Closest distance of endoscope and borescope

The closest distance to the object within the in-focus range (observation distance) is called the closest distance.


The closest distance has characteristics depending on the type of endoscope.


1. Endoscope equipped with advanced camera

Since there is a camera at the tip, the optical closest distance is longer.


In the case of our endoscope, the closest distance is 10 mm.
The recommended viewing distance is 10-60mm.





Although it is made by another company, some low-priced models seem to have a closest distance of about 40mm.






2. Borescope


Borescopes and fiberscopes have relatively short closest distances.

This is not a guaranteed value as there are individual variations, but when connecting a camera with our borescope, the closest distance is approximately 5 mm.



Lens focus tonality can be adjusted, but there are limits.

The limit is around 5mm.

ボアスコープの最至近距離02   When we checked with our current product, the closest distance was 4.5mm.





◆How to shorten the closest distance


By inserting a close-up ring (5mm), the closest distance can be reduced to about 3mm.






When using our current product with a close-up ring (5mm), the closest distance was 2.5mm.





The “borescope camera” used this time is available at our company.

Additionally, our Borescope Camera Adapter Lens is equipped with a 5mm close-up ring as standard.

For details, please see the product page below.


How to cool a heat-resistant borescope

For heat-resistant borescopes that exceed 150℃, we cover them with a heat-resistant jacket (custom-made product).









Insert water for cooling and air for tip purge into the heat-resistant jacket.

In other words, a chiller device (low-temperature circulation high-temperature water tank) that circulates cooling water is required.

Set the water cooling outlet of the heat-resistant jacket so that the temperature is approximately 60℃ or less.

We can also propose a chiller device (low-temperature circulation high-temperature water tank) that circulates cooling water.

We will have a detailed meeting with the customer, but the following information is required at a minimum.

① Distance from chiller device → water cooling inlet

②Water cooling outlet → Distance to chiller device

③Height difference between chiller device and borescope mounting position

④ Size of heat-resistant jacket, etc.


Heat resistant borescope

A bore is installed in the observation section (high temperature section), and a camera is connected to the end of the bore for observation.





When observing images under high temperature using a heat-resistant borescope,
The following two methods are the main methods.


Without cooling device

Our borescope also has a heat-resistant type (compatible with 120℃).



耐熱ボアスコープ 120℃対応ボアスコープ(φ4.0mm)


●Heat-resistant borescope that can handle up to 120℃
●Enables non-destructive visual inspection of the inside of narrow parts that cannot be directly reached by the human eye.
●Compatible with various types of lighting such as M10 P=1.0 and M10 P=0.5
●Viewing direction: 0° (direct view), 30° (side view), 70° (side view)

耐熱ボアスコープ 120℃対応ボアスコープ(φ2.7mm)


The compatible temperature is 120℃, but it is usually in stock and low price.



If it is a made-to-order product, we have borescopes that can handle up to 150℃.


Please refer to the website for details.



With cooling device

If a cooling device is attached to the borescope, it can handle temperatures up to quite high temperatures.
It can also handle extremely high temperatures exceeding 2000℃.
This can be achieved by covering our borescope with a diameter of 4 mm or more (see our website for details) with a heat-resistant jacket (custom-made).






Insert water for cooling and air for tip purge into the heat-resistant jacket.




Most of the super heat-resistant borescopes are made to order.
Production begins after detailed discussions with the customer.
The price will be several million yen.


For details on borescopes
Please feel free to contact Shodensha technical staff 
We will make individual proposals tailored to each company.


Heat-resistant Borescope



In the observation section (high-temperature area), a bore is installed, and a camera is connected to the end of the bore for observation.





When observing images under high temperature using a heat-resistant borescope,
The following two methods are the main methods.


Without cooling device


Our borescope also has a heat-resistant type (compatible with 120℃).



耐熱ボアスコープ 120℃ compatible borescope (φ4.0mm)
Click here for product details


●Heat-resistant borescope that can handle up to 120℃
●Enables non-destructive visual inspection of the inside of narrow parts that cannot be directly reached by the human eye.
●Compatible with various types of lighting such as M10 P=1.0 and M10 P=0.5
●Viewing direction: 0° (direct view), 30° (side view), 70° (side view)

耐熱ボアスコープ 120℃ compatible borescope (φ2.7mm)
Click here for product details


The compatible temperature is 120℃, but it is usually in stock and low price.



If it is a made-to-order product, we have borescopes that can handle up to 150℃.


Please refer to the website for details.



With cooling device


By attaching a cooling device to the borescope, it can withstand significantly high temperatures. It can even handle ultra-high temperatures exceeding 2000°C. This can be achieved by covering our borescopes with a heat-resistant jacket (custom-made) for borescopes with a diameter of φ4mm or larger (please refer to our website for details).






Insert water for cooling and air for tip purge into the heat-resistant jacket.




The ultra-heat-resistant borescopes are mostly made to order. After detailed discussions with the customer, production will commence. However, please note that the price for these custom-made products can reach several million yen.

For further details regarding the borescopes, please feel free to contact our technical staff at shodensha. We are more than happy to discuss your requirements and provide individual proposals tailored to your company’s needs.


Features of the φ1.8mm Borescope:

About φ1.8mm Borescope
Inspection of workpiece interiors and holes that couldn’t be directly observed before can now be conducted through non-destructive inspection using an ultra-thin borescope with a tip diameter of 1.8mm. With an effective length of 95mm, it offers excellent maneuverability, making it easy to inspect small parts and molds. Due to the proximity of the target object to the eyes during inspection, it helps reduce physical and eye strain.
When it comes to ultra-thin scopes, one might think of a narrow field of view, but our model features a wide 80° field of view despite its slim design. Additionally, the lenses provide extremely sharp images, allowing for comfortable observation without discomfort.
Of course, by using a camera adapter, you can connect it to a C-mount camera and view the images.

You can view it in our showroom.


Due to its ultra-thin design, it is highly fragile, so we do not lend out demonstration units. We apologize to those who wanted to try it out, but we would be grateful if you could consider visiting our showrooms in Osaka or Tokyo.

When using a fixed-focus lens alone, close-up photography is not possible due to its minimum focusing distance.

We have confirmed the conditions necessary to secure a 10mm field of view. (The camera uses a 1/3-inch sensor)


■When using an f=25mm lens



“Focal length approximately 70mm

f=25mm lens + 5mm close-up ring”



The field of view is approximately 10mm in the vertical direction


固定焦点レンズで10mm視野確保02   固定焦点レンズで10mm視野確保03




■When using an f=16mm lens



Focal length approximately 35mm

f=16mm lens + 5mm close-up ring




固定焦点レンズで10mm視野確保05   固定焦点レンズで10mm視野確保06




The ‘fixed-focus lens’ used in this observation is available from our company.

For more details, please visit the product page below

The difference in appearance due to the aperture control of the macro zoom lens

We have a macro zoom lens with aperture control available at our company.

We’ll compare the differences in appearance due to the aperture





The shooting range is as shown in the above photo, but for a clearer comparison, we will enlarge and compare the red-framed area (including scratches, rough surfaces, and metallic surfaces)





1.Fully open aperture

The image becomes brighter and the resolution increases, but the contrast decreases






2.Stop down a bit

The image achieves a balanced mix of color reproduction, contrast, and resolution.






3.As narrow as possible.

The depth of field becomes deeper, but the resolution decreases







If you observe the same field of view with a medium magnification macro zoom lens, it will look like the following






The details of the ‘macro zoom lens with aperture control’ used this time can be found on the following product page.

Cách đạt được độ phóng đại 100 lần với tiêu cự 300mm

The silver part of our company’s long-distance lens (rear converter) is removed.



It’s a long-distance lens with a magnification ranging from 4x to 40x when the focal length is 300mm.
※ Magnification is calculated based on a 1/2.5 inch camera, equivalent to a 17-inch monitor.

A 5x rear converter is attached.



However, attaching a 5x rear converter will decrease both brightness and resolution.

Our long-distance lens is equipped with a focusing adjustment function, so you can use it with focal lengths ranging from 200mm to 400mm. When attaching the 5x rear converter, if the focal length is set to 200mm, the magnification will be approximately 150x.

The method of attaching ring lighting to a slim lens

1. Attach a dedicated fixed ring to the tip
2.Utilize an easy arm for ring lighting


You can move the three joints freely

It can be attached to a 3D arm (horizontal branch
When attached to a 3D arm, tilting the lens also tilts the LED ring light simultaneously, which is convenient  
“Of course, it can also be attached to a support pillar.”

The method of attaching the filter

The filters to be attached to the lens usually have ‘male and female threads of the same size’.



If it’s a 30.5mm filter, both would be labeled as M30.5mm. Therefore, you can stack multiple filters of the same size and use them together



Of course, it can also be attached to a 30.5mm lens. In the case of a universal lens, since the lens side has a female thread, you would attach the male threaded side of the filter.。





If you need to change the diameter, conversion rings like the following are available.

(The following is a ring for attaching a 37mm filter to a 28mm diameter lens.)



Lens and Filter Cleaning Method



I will describe the cleaning method for lenses and filters.

Lenses and filters can accumulate dust, debris, dirt, fingerprints, and other particles.

When cleaning, please follow the steps below.


**Items Needed:**


– Commercial lens blower
– Commercial lens cleaning tissues, paper, or lens cleaning cotton swabs
(Items with low or no dust generation)
– Commercial lens cleaning solution or high-purity ethanol

There are products available that combine the above items into one set.





Product by KING (Asanuma Corporation):

Camera Cleaning Kit


While a canned air duster can be used as a substitute for the blower, some canned air dusters may release fine water droplets. Please avoid using this type for lens and filter cleaning.




(1)Use the blower to blow away coarse debris from the surface of the lens or filter


If you wipe while dust is still adhered, it may scratch the lens surface or cause the coating to peel off. Please ensure thorough blowing to remove dust completely.






(2)Wrap lens cleaning paper around a lens cleaning stick or similar tool


While tweezers can be used as a substitute, if the paper tears and the metal directly touches the lens, it may scratch the lens surface or cause the coating to peel off. Please avoid using metal tweezers or those with sharp tips.





(3)Drip a few drops of cleaning solution onto the wrapped cleaning paper to moisten it.


(4) Wipe the surface of the lens

“There are two methods for wiping: radiating from the center to the periphery and spiraling from the center to the periphery. Choose according to the direction of dirt.




Please wipe gently. Wiping vigorously may cause the coating on the lens surface to peel off.”







(5)When there are water droplet residues, dry wipe.


Please wipe gently during this process. Wiping too hard may cause the coating on the lens surface to peel off.

How to attach the lens to the small diameter ring light

Introduce two types of ring lights


省スペースLED照明 細径40灯LEDリング照明
Space-saving LED lighting LED-16



40 small diameter LED ring lights



Outer diameter φ48mm
Inner diameter φ15mm



Outer diameter φ63mm
Inner diameter φ27mm



16 lights flat
(The LED angle is 0°, pointing straight down.)



40 lights direct
(The LED has an angle)







<mounting method> <mounting method>
Exclusive for M28/M42
(M42 is a standard called T-mount)
The M28 female thread uses three fixed screws.
省スペースLED照明 細径40灯LEDリング照明
The slim lens is secured using M28.省スペースLED照明 The slim lens is secured using M28.細径40灯LEDリング照明
The standard lens (SDS-M) is secured using M42.

The standard lens (SDS-M) is secured using three-point screws


To reduce image distortion

Telecentric lens


Telecentric lenses allow you to obtain images with less distortion.

I experimented with our telecentric lenses RT3 and RT5.



テレセントリックレンズ RT3、RT5 Telecentric lens RT3, RT5
Attach it to the USB camera.
I took a photo of the glass scale.
テレセントリックレンズ RT3 テレセントリックレンズ RT5で撮影
Photographed with telecentric lens RT3 Photographed with telecentric lens RT5
You can see that there is no distortion in the four corners of the screen.
This is the feature of telecentric lenses.



CCTV lens

If you are using a CCTV lens, a telephoto lens will have less distortion than a wide-angle lens.
I experimented with a 6mm fixed focus lens and a 25mm fixed focus lens.


8mm 固定焦点レンズ I attached an 8mm fixed-focus lens to a USB camera and took a picture of graph paper.
方眼紙の四隅が歪んでいる It is evident that the four corners of the graph paper are distorted.


25mm 固定焦点レンズ “I attached a 25mm fixed-focus lens to a USB camera and took a picture of graph paper.”
方眼紙の四隅に歪みがあまり見られません。 There isn’t much distortion observed at the four corners of the graph paper


If it’s a macro lens, some lenses have less distortion depending on their performance, but they tend to be more expensive as a result.





– By using a telecentric lens, you can obtain images with minimal distortion.
– The characteristic of a telecentric lens is that there is no distortion even at the four corners of the screen.
– If you are using a CCTV lens, using a telephoto lens rather than a wide-angle lens will result in less distortion.

Types and characteristics of telecentric lenses

Main features of telecentric lenses


1. There is no expansion or contraction of the image within the depth of focus.
→It is possible to reduce measurement errors when measuring dimensions.
2. Less image distortion due to parallax
3. When used in conjunction with coaxial lighting, the brightness of the object is less uneven.
There are two main types of lenses: bilateral telecentric lenses and unilateral telecentric lenses.
We also handle both double-sided and single-sided telecentric lenses.


The characteristics of each are as follows.



Bilateral telecentric lens




A feature of this camera is that the projected size of the subject remains the same regardless of the distance between the camera sensor and the subject.
In other words, by changing the distance on the camera sensor side using a close-up ring, etc., you can change only the distance between the lens and the subject without changing the magnification.
However, the diameter of the lens is physically larger than the area to be projected, so the lower the magnification, the larger the lens size and the higher the price.
Used in precision measuring equipment and projectors.


両側テレセンリックレンズ   両側テレセントリックレンズ




Unilateral telecentric lens



This lens has a telecentric lens structure only on the subject side.
Unlike a double-sided telecentric lens, when the distance to the camera sensor side changes, the size of the subject will change, just like a non-telecentric lens.
The lens is smaller and less expensive than a double-telecentric lens.
If changing the magnification like a macro zoom lens is not necessary for dimension measurement purposes, it may be used as a fixed magnification replacement.


(In addition to the subject-side telecentric lenses that we handle, there are also image-side telecentric lenses that have a telecentric lens structure only on the camera sensor side.
This is rarely used when photographing workpieces using a regular camera. )






















Special telecentric lens

■Long distance telecentric lens


特殊なテレセントリックレンズ01   特殊なテレセントリックレンズ02


A distance of 170 mm can be secured from the tip of the lens to the object.

At this level of magnification, there is not much difference in resolution compared to our zoom lens.

This is effective if you really want to make the lens and camera smaller.


telecentric lens


(Working distance:170mm)

TG lens + 0.5x auxiliary lens

(focal length: 170mm)

特殊なテレセントリックレンズ03 特殊なテレセントリックレンズ04




■Space-saving, high-magnification telecentric lens


特殊なテレセントリックレンズ05   特殊なテレセントリックレンズ06


The lens is small and the focal length is short at 40mm, making it convenient for installation in tight spaces.

Although the magnification is high, the resolution is lower compared to our zoom lens.



Space-saving, high-magnification telecentric lens

FZ lens + 2x auxiliary lens

特殊なテレセントリックレンズ07 特殊なテレセントリックレンズ08
(⇓Enlarge the red frame above) (⇓Enlarge the red frame above)
特殊なテレセントリックレンズ09 特殊なテレセントリックレンズ10

2Kigou pitch discrimination and number discrimination are not possible with a telecentric lens.




(Reference) When viewed with our highest resolution lens, it looks like the following.









The main features of telecentric lenses are

1. Since there is no expansion or contraction of the image within the depth of focus, measurement errors can be reduced when measuring dimensions.
2. Less image distortion due to parallax
3. When used in conjunction with coaxial lighting, the brightness of the object is less uneven.

And so on.

Double-sided telecentric lenses used in precision measurement equipment and projectors.
There are single-sided telecentric lenses, which have a telecentric lens structure only on the subject side.
Double-sided telecentric lenses are large and expensive, while single-sided telecentric lenses are small and relatively inexpensive.

The difference between back focus and flange back?

Q: What is back focus


A: Back focus refers to the distance from the rear end of the lens to the focal plane (the imaging sensor of the camera).


If the back focus is misaligned, it will result in a focus shift.


Q: What is flange back?



A: Flange back refers to the distance from the lens mount’s mounting surface to the imaging sensor.



There can be confusion between flange back and back focus, but they are distinct concepts.

The distance from the camera’s C-mount to the imaging sensor surface (flange back) may vary slightly depending on the camera. Therefore, when changing lenses or cameras, it may be necessary to adjust the back focus.
(We ship products that combine cameras and lenses with precise adjustments.)
Additionally, for lenses with a back focus adjustment mechanism, customers can also make fine adjustments themselves.

We also offer lenses with a back focus adjustment mechanism as optional accessories.



Back focus mechanism lens SDS-M19

For detailed product information, please contact our technical support.

Accessory to extend the focal length of a microscope

There is an option called the ‘0.5x auxiliary lens’ that approximately doubles the operating distance. (Please note that some models may not have the option of auxiliary lenses available.)


標準レンズ用0.5倍補助レンズ TG-0.5
0.5x Auxiliary Lens for Standard Lens: TG-0.5

<Changes in Operating Distance>
* With the optional 0.5x auxiliary lens (TG-0.5) for the standard lens:


Without TG-0.5
(installed on TG500CS)
With TG-0.5
(installed on TG500CS)
Working distance


When using the 0.5x auxiliary lens, the operating distance becomes longer, and the distance between the lighting and the object also increases. Therefore, it is necessary to use the lighting LED angle (bottom: LED-A2) to fix the lighting near the object.



LEDアングル(LED-A2) LEDアングル(LED-A2)取付例
LED angle(LED-A2) Mounting Example

If you have any questions, please feel free to contact technical support.”

What is chromatic aberration?

Chromatic aberration refers to the displacement (color shift) of an image created by a lens due to the wavelength of light. Even when using the same lens, the refractive index of the lens varies depending on the wavelength of light, causing differences in focal length based on color. As a result, when looking through the lens, the position where the image is focused shifts, causing blurring.


In a state where chromatic aberration is occurring:
Blue, red, and green light are not focused together, but are dispersed separately.


To mitigate chromatic aberration, there are compound lenses such as achromatic lenses, which are made by bonding several types of lenses together. While using these lenses can minimize chromatic aberration as much as possible, it cannot be completely eliminated.

Useful goods when you want to increase your W.D

If you don’t mind sacrificing magnification, use a 0.5x auxiliary lens to increase W.D.


標準レンズ専用0.5倍補助レンズ 標準レンズ専用0.5倍補助レンズ


When a 0.5x auxiliary lens is attached to the TG500PC2, the standard 23x to 140x becomes 11x to 70x, and the standard focal length of 90mm increases.
Changes to 160mm.


However, in this case, the position of the LED ring light attached to the tip of the lens will be moved away from the object and the light will become dark, so it is necessary to improve the lighting by changing to a higher brightness light or removing the diffuser plate. will become necessary.



高輝度80灯LEDリング照明 GR-80N2 高輝度80灯LEDリング照明
着脱可能な拡散板付き With removable diffuser plate



It is possible to change the position of the lighting using the LED angle, but this will interfere with the extended W.D., so use twin arm lighting (SPF-D2), LED spot lighting (SPF-FL3), etc. We recommend.



LEDアングル Even though I used a 0.5x auxiliary lens to extend the W.D.
If you lower the position of the lighting using an LED angle
This will interfere with the W.D. that you have worked so hard to develop.



Therefore, we recommend using twin arm lighting (SPF-D2), LED spot lighting (SPF-FL3), etc.


ツインアームLED照明 SPF-D2 ツインアームLED照明 SPF-D2


Stationary type dimmable LED twin arm lighting.


Please contact technical support for details.

Lens numerical aperture and resolution

1.What is lens resolution?


When observing an object with magnification, magnification is of course important, but

It is also important to be able to discern fine details.

This ability is called resolution,

It is expressed as “the minimum distance that allows two points that are close to each other to be distinguished.


Resolution = Distance at which two points can be identified


*If you are observing the presence or absence of minute objects, it is possible to check even smaller objects.

Expressed mathematically, resolution = kλ/NA.

k is a coefficient and values ​​of 0.61 and 0.5 are used.

λ is the wavelength of light. For normal visible light, use 0.55μm.

NA is the numerical aperture of the lens. (This value indicates one of the lens’s performance.)

The larger the numerical aperture, the higher the resolution (smaller the numerical value).


(Example) If the lens has a numerical aperture (NA) of 0.9,

Resolution = 0.5×0.55/0.9 = 0.30μm.


If the distance between two points is 0.30μm, two points can be identified.

There is no relationship between resolution and magnification, so no matter how much you increase the magnification with this lens,

The discrimination between two points is 0.30μm.



2. Numerical aperture of lens


This is an important value that determines the performance of the lens.

Numerical aperture (NA) = nsinθ

n is the refractive index of the medium from the object to the lens, and if it is air, n = 1.

θ is the amount of light that enters the lens from the point where the optical axis intersects the object.

This is the outermost angle.




The larger the numerical aperture

This will be a bright lens.

Also, since resolution = kλ/NA, the larger the numerical aperture, the

The resolution will be higher. (The number will be smaller.)


3. Examples of our megapixel compatible telecentric lenses



The numerical aperture is 0.026.

Resolution = (0.61×0.55)/0.026 = 12.9μm. 

This almost matches the resolution (12.7μm) in the table above.



4. Examples of our medium magnification zoom lenses


The numerical aperture of our medium magnification zoom lens (SDS-M) ranges from 0.014 (at the lowest magnification) to 0.036 (at the maximum magnification).

Resolution at lowest magnification = (0.61×0.55)/0.014 = 23.9μm

Resolution at maximum magnification = (0.61×0.55)/0.036 = 9.3μm.

What is an auxiliary lens (rear converter lens)?

By installing it between the camera and the main lens, you can change the magnification without changing the W.D. (working distance).
However, the disadvantages are that the brightness decreases (the F value increases), the resolution and contrast decrease, and the focus becomes poor.


Attach it between the camera and the main lens.

What is a macro lens/macro zoom lens?

A lens designed for close-up photography is called a macro lens.
A macro zoom lens is one in which the magnification can be changed continuously and the focal length is constant (does not change).




Strictly speaking, lenses that can change the magnification continuously but whose focal length changes are not called zoom lenses.
Sometimes called variable magnification lenses to distinguish them from zoom lenses.



If you want to keep the price down without changing the magnification frequently, we recommend a variable magnification lens, and if you change the magnification frequently, we recommend a macro zoom lens.

Relationship between depth of field and working distance

The following two methods are typical for deepening the depth of field.

(1) Increase the depth of field distance.

(2) Narrow down the optical path *For information on aperture, please refer to “What is depth of focus/depth of field?”


This time I will explain (1).



■ Relationship between depth of field and working distance

Below is a spec table for lenses of the same manufacturer, same series, and same magnification (X4).
The longer the W.D., the deeper the depth of field.






■Actual measurement of depth of field due to differences in working distance


Comparative imaging using lenses from the same manufacturer and series but with differing working distances, observing a glass scale with a 0.2mm pitch tilted at a 45-degree angle and viewed from directly above.






(1) Observation using a lens with an optical magnification of 6x and a working distance of 40mm.




If you determine that the focus is aligned with one increment (0.2mm), then the depth of field can be calculated as 0.2mm x (1/√2) = 0.14mm.



(2) Verification using a lens with an optical magnification of 6x and a working distance of 110mm.




If you determine that the focus is aligned with two increments (0.4mm), then the depth of field can be calculated as 0.4mm x (1/√2) = 0.28mm.

Automation and efficiency of metallographic grain size measurement


1.What is graphite nodularity rate?

Metal materials are used in all fields, and there are many types of metals.
Appropriate materials must be selected according to the application and purpose.
Cast iron is one of those metal materials.




Cast iron is a composite material in which graphite (nonmetal) is dispersed three-dimensionally within steel.
Depending on which form of graphite exists, mechanical properties such as tensile strength and elongation, and physical properties such as thermal conductivity vary.
In particular, mechanical properties such as tensile strength and elongation require an average graphite spheroidization rate of 80% or more when observed under a microscope (100x magnification).
Therefore, graphite nodularity is an important evaluation criterion to guarantee tensile strength and elongation.





2. Method of graphite nodularity analysis

To analyze the graphite nodularity rate, follow the steps below.

① Pre-treatment process: Rough cutting for large samples
②Pre-treatment process Resin embedding
③Pre-treatment process: Cutting the sample
④Pre-treatment process: Rough polishing of the cut surface
⑤Pre-treatment process Fine polishing of the cut surface
⑥ Pre-treatment process Buff polishing of the cut surface to a mirror finish
⑦ Pre-treatment process Etching treatment with chemicals (burning the surface with chemicals)
⑧ Microscope observation
⑨Classification, counting, calculation

There are many pre-processing steps and it takes a lot of time.
For observation, microscopic observation (100x magnification) is performed using a metallurgical microscope.
“We use classification based on roundness coefficients standardized by JIS industrial standards and numbers based on size.”
These are used to calculate the graphite nodularity rate, such as area calculation and counting.




Calculation of graphite nodularity in microscopic structure
① In principle, the magnification is 100x, and the test is performed on 5 fields of view, and the average value is calculated.
② Graphite and inclusions smaller than 2mm (actual size 20μm) are not covered.
③ Compare and classify with the classification table.
④ Find the ratio (%) of the number of graphite grains with shapes V and VI to the total number of graphite grains and use it as the graphite nodularity rate.
I will do it.
It is an analog method and requires complicated work and is time consuming.
Including the pretreatment process, the work requires a considerable amount of time and effort, is prone to human error, and is difficult to evaluate.



3.Improving the efficiency of graphite nodularity analysis

Therefore, we would like to propose a method using graphite spheroidization software.
This is a method of clearly photographing spherical graphite magnified with a microscope and analyzing it using software.
This is done through image analysis processing according to the calculation method described above.
The image shows graphite spheroidized into various shapes and sizes.
In addition, it is possible to automatically measure the area and count graphite from the high-definition image.
Additionally, still images and accurate values ​​can be output in Excel format, streamlining the entire process leading up to report creation.


Click here for details on graphite nodularity measurement software

黒鉛球状化率測定ソフト(日鉄テクノロジー株式会社製) KKS04



4. What is the set that can efficiently analyze graphite nodularity rate?

Recommended for those who want to analyze large cast iron, carry it around, and easily measure graphite nodularity!
●Set of small and simple metallurgical microscope (with camera) and graphite nodularity measurement software



小型簡易金属顕微鏡 KKKI-STD6-130DN



Easy to observe large cast iron
A small and portable metallurgical microscope








Recommended for those who want to seriously measure graphite spheroidization rate!

●Set of metallurgical microscope, microscope camera, graphite nodularity measurement software


倒立型金属顕微鏡 (超高倍率顕微鏡) 倒立型金属顕微鏡 (超高倍率顕微鏡) GR-29J-C3J


顕微鏡用USB3.0カメラ(500万画素) HDCT-500DN3









It is efficient to use software to measure graphite nodularity.
We have convenient simple sets and full-scale sets available.

Replaces visual inspection with a microscope

Visual inspection from microscope to microscope

I think the use of microscopes for inspections in inspection lines and similar settings is quite common. Inspections with microscopes can be very tiring, placing a significant burden on inspectors. That’s why many people are considering replacing microscopes with magnifying scopes. However, there are also many types of magnifying scopes, and choosing the right one is crucial to avoid adding unnecessary strain. There are three key points to consider when switching from microscopes to magnifying scopes.




Three important points for replacement


①Choose a model with a high frame rate


The magnifying scope displays images on a PC or monitor. If the frame rate is low, the displayed images won’t move smoothly, causing additional stress. Frame rate is expressed as a numerical value, and the optimal range where people don’t feel discomfort is around 50 to 60 frames per second (fps). Below 30 fps, discomfort becomes more noticeable. Models that can be connected to a PC often suffer from low frame rates due to USB communication speed issues. Therefore, it’s recommended to choose a model that can be directly connected to a monitor.




②Choose a model with good color reproduction


The appearance through the camera used in the magnifying scope can vary. Consequently, there are cameras with excellent color reproduction and those with less impressive performance in this regard. When colors are not accurately represented, it can cause discomfort and stress as our brains perceive discrepancies. Even a slight shift, like red appearing slightly orange, can induce stress. Opting for a Full HD camera can provide relatively high color reproduction accuracy, resulting in clear and vivid images.


③Choose a model with a wide dynamic range


You might not often hear the term “dynamic range,” but I’ll explain it simply. It refers to the ability to capture both bright and dark areas simultaneously without overexposing or underexposing either. When adjusting brightness for one, the other may become washed out or too dark.

To overcome this, a camera with a wide dynamic range is necessary. Dynamic range is a characteristic of cameras, and it varies between different models. Compared to typical cameras, the human eye is remarkably adept, with a wide dynamic range.

Many discrepancies between what we see with our eyes and what is captured by a camera can be attributed to differences in dynamic range. Some models highlight their wide dynamic range capabilities, so choosing such models would be optimal.



The recommended model


It sounds like your company offers a model that meets all three criteria mentioned. The Full HD microscope with a frame rate of 60fps ensures smooth viewing, while the color reproduction is exceptionally clear due to the Full HD resolution. Additionally, the model features HDR (High Dynamic Range) functionality, providing a wide dynamic range to capture both bright and dark areas effectively.

With demo units available, I encourage you to give it a try. It seems like an excellent opportunity to experience the capabilities of the microscope firsthand.

About cameras for fluorescence microscopes

Fluorescence is a weak amount of light emission and requires a highly sensitive camera.

Therefore, the camera used for fluorescence microscopy is usually a cooled CCD camera (monochrome).


Recently, there is also fluorescence emission in the visible light range, and if there is an amount of fluorescence emission at the visible light level (a level that can be seen with the naked eye), fluorescence observation can be performed with a single color camera.


In that case, there are some things to keep in mind, so please check the following.







Sensitivity is the ability to distinguish between noise and signal.

Noise occurs when the original signal cannot be distinguished from the signal emitted by the equipment.

Camera shooting under low light usually produces noise.


There is one more thing, another noise.

Noise occurs during fluorescence observation when “dark current” is generated due to an increase in exposure time.

Dark current is the leakage of electrons during camera exposure, and dark current has the property of doubling for every 7°C rise in temperature.

Sensor temperature has a large effect on dark current, but especially when shooting under low light and the exposure time is long, it can lead to a decline in the signal-to-noise ratio and image quality.

To prevent this, the camera usually has to be cooled. Therefore, a cooled CCD is used.

However, depending on the fluorescence conditions, this may not be necessary.

Generally, cooled CCD cameras are often expensive, and as long as the fluorescence reaction is strong enough, there is no problem even if the camera is forced to cool using a fan or Peltier device.




・Check wavelength sensitivity

Is the camera sensitive to fluorescence wavelength?

Light has wavelengths, and we need a camera sensor that can detect the fluorescent wavelengths. Although it depends on the conditions, fluorescence emission is generally a very weak amount of light.

First, we need to make sure that the camera can detect and is sensitive to that fluorescence wavelength.

You can tell whether a camera has a sensitivity characteristic by looking at its spectral sensitivity characteristic diagram.




・dynamic range

A camera sensor converts light into a signal with a “dynamic range” (the ratio of the maximum to minimum required amount of charge), which determines the camera’s light detection performance.




・Is the camera sensor CCD or CMOS?

Although CCD sensors are still installed in high-end cameras, they are becoming less common due to the rise of CMOS sensors.

In particular, recent CMOS sensors have almost the same performance as CCD sensors in terms of cost, number of pixels, speed, noise, power consumption, etc., so I don’t think you need to worry about that.




・Is the shutter method global shutter or rolling shutter?

CCD sensors only have a global shutter method.

For CMOS sensors, you can choose between global shutter method and rolling shutter method.

If the subject is moving, this difference in shutter method will greatly affect the image quality.


Rolling shutter has poor ability to follow movement. This method sequentially exposes each sensor row at a time, so if the subject moves, the image will be distorted.

On the other hand, global shutter has good ability to follow movement. This is because the sensor is exposed all at once, so there is no difference in exposure time.

However, if you are photographing while the object is still under microscope observation, there is often no problem with the rolling shutter method.




・Monochrome camera or color camera?

For general fluorescence observation, monochrome cameras are preferred due to their high sensitivity.

Color cameras have lower sensitivity than monochrome cameras. The cause is the Bayer filter.

This filter is necessary to capture the color information of the image, but it only allows light of certain wavelengths to pass through, reducing the amount of incoming light.

Furthermore, the use of an IR cut filter in front of the camera sensor that cuts out infrared light is another factor contributing to the decrease in sensitivity.


Therefore, when analyzing coexisting molecules using multiple fluorescent substances, it is generally necessary to combine light sources and filters according to their respective excitation and fluorescence wavelengths, and to take images with multiple monochrome cameras.


Recently, there is also fluorescence emission in the visible light range, and as long as the amount of fluorescence emission is at the visible light level (a level that can be seen with the naked eye), fluorescence observation is often performed with a single color camera.




・Number of pixels

You can choose a camera with the number of pixels that suits your purpose.

If you want to shoot with a high pixel count, you tend to choose a camera with a high pixel count, but if you have a high pixel count, the sensor size (number of sensor inches) will generally be larger, making it more likely that vignetting will occur when taking pictures with a microscope. Caution is required.

Therefore, it is necessary to select a camera with the optimal number of pixels that suits the purpose and microscope.





A cooled CCD is not absolutely necessary for fluorescence photography.

There is also fluorescence emission in the visible light range, and if the amount of fluorescence emission is at the visible light level (a level that can be seen with the naked eye), fluorescence observation is often performed with a single color camera.



Although we do not handle cooled CCD cameras, we do have color cameras that emit fluorescent light in the visible light range, and that emit fluorescent light at the visible light level (a level that can be seen with the naked eye).

Please see below for product details.

How to take microscopic photos with a compact digital camera

No special equipment is required when taking microscopic images with a small digital camera.
If you hold it close to the eyepiece, you can take beautiful pictures.
However, it is susceptible to camera shake, so it takes some getting used to.


There are various fixing devices on the market to prevent camera shake.
I’m sure there are specialized equipment, but I’d like to introduce an easier and cheaper way to take pictures.


There is a product called a quick bracket for astronomical telescopes.
You can easily get it online for less than 10,000 yen.



Usually used for astronomical telescopes and field scopes.



In fact, it can be attached to the eyepiece of a microscope using the same attachment method shown in the photo above.
Since it is made for astronomical telescopes, the fixed part is a little large and cannot be attached to all microscopes, but it can be attached to φ30mm eyepieces such as stereo microscopes.


Just use this bracket to align the optical axis and release the shutter to take microscopic photographs.。



If your camera has a zoom function, you can also take a slightly improved version of the overall photo.



It can also be attached to the three-eye part (JIS tube) of a microscope to take pictures.
This requires some tips, so if you are interested, please contact us.


How to connect a camera to a monocular (microscope)


There are various types of monoculars.
Some have removable eyepiece lenses, while others cannot.


■If the eyepiece lens cannot be removed
When the eyepiece diameter is φ30mm to φ32mm and made of hard material such as resin




You can attach a camera by connecting an adapter lens like the one below to the eyepiece part.。




可変倍率カメラアダプタレンズ BA-A1835 可変倍率カメラアダプタレンズ BA-A1835
カメラアダプタレンズ BA-A35 カメラアダプタレンズ BA-A35


■When the eyepiece lens can be removed
When the inner diameter of the straight cylinder after removing the eyepiece is 23.2 mm (JIS standard)




You can connect a C-mount camera by removing the eyepiece and inserting a relay lens in its place as shown below.









About the appearance when using a microscope camera with a microscope

Observation with a camera attached to a microscope

A microscope is a device that is used by looking through an eyepiece with the naked human eye.
The premise is that humans can see small objects by enlarging them.
If you want to take and save images of what you see through the microscope, or share the images with other people, you can use a camera.
Our microscopes come in binocular and trinocular types.


Binocular type Trinocular type


Binocular types have two eyepieces that you look through with your eyes.
The trinocular type has two eyepieces for viewing with the eyes + one camera connection port, for a total of three eyes.
It becomes.


Our microscope camera can be attached to either binocular or trinocular type to take pictures.
If you use a binocular type, you have to remove the eyepiece and replace it with a microscope camera.
If you plan on installing a camera, we recommend the trinocular type.
If it is a trinocular type, you can observe with the binocular eyepieces while the camera is attached to the trinocular part.


Example of installation on binoculars Example of attachment to trinocular part




●What problems occur when attaching a camera to a microscope?

As mentioned above, microscopes are originally used to magnify small objects and observe them with the naked eye.
This is the main purpose of the premise.
Attaching the camera to the microscope and taking pictures is the second objective, and it is a rather forced and brute force method.
As a result, the following problems occur.



When observing through a microscope, even though the entire field of view is clearly in focus,
When I attached the camera and looked at it on the monitor, it was out of focus.






●The microscopic image taken with the camera is out of focus. What is the reason?

Due to its structure, a microscope has two characteristics that make it difficult to focus on the entire surface when using a camera.


・Feature 1


As mentioned above, the main purpose of a microscope is to magnify small objects and observe them with the naked eye.
Shooting with a camera is a brute force method with a secondary purpose.
Therefore, due to its structure, the objective lens of a stereomicroscope is intentionally placed at an angle.


Objective lens arrangement of stereomicroscope


In this way, the objective lens of a stereomicroscope points slightly inward.
This structure is purposely designed to create a three-dimensional effect when viewed with both eyes.
This is the same as attaching the lens to the camera at an angle when using the camera.
Also, the situation where you use a camera and view the image on a monitor is not the same as looking through both eyes.
This is how you see it with one eye.
Therefore, even if the camera is installed directly above the microscope,
The situation is the same as taking a picture by tilting the camera at an angle.
Since the image is shot from an angle, there is also the problem of depth of field, which makes it difficult to focus on the entire image.



Feature 2


Many industrial cameras use elements that are a little smaller than 1/2 inch.
If you try to take a magnification image that is close to what you see when looking through a microscope,
It is necessary to use a camera adapter lens that lowers the magnification, such as 0.45x or 0.37x.
Lenses that reduce this magnification are prone to lens distortion, making it difficult to focus on the entire camera image.




*Recently, high-resolution industrial cameras have come out, and 1-inch elements are being used.
In that case, a 1x (1x) lens can be used, which reduces the effects of distortion.
Please contact us for details.


I actually took a photo.
The photo below was actually taken of a 10 yen coin using a microscope, camera, and 0.45x lens.


The left side is in focus, but the right side is blurry.


When attaching a camera to a microscope for photography, it’s common to encounter situations where the entire screen is not in focus, unlike the clear view observed when using the microscope with the naked eye. This discrepancy can indeed feel disconcerting. However, as mentioned earlier, achieving focus across the entire field of view when using a camera with a microscope is challenging.





●How to focus a microscope image

However, by focusing on the center of the image while looking at the camera image, the out-of-focus area can be divided into left and right parts.
It is possible to adjust the image to be relatively easy to observe.



Focus on the center of the screen, and the left and right sides are evenly out of focus


The image is that the center of the image is in focus, and the sides are slightly out of focus.
If you adjust the focus position to the center of the screen in this way, you can take relatively clear microscope images.





●How to match the focus of the eyepiece and camera (C mount)

・The focus between the eyepiece and the monitor often does not match!?

When taking microscope images, it is preferable that the focus of the naked eye observation and the camera image be perfectly aligned.
However, due to “differences in optical paths” and “variations in manufacturing,” the focus of the eyepiece (naked-eye observation) and camera port (camera observation) often do not match.




① When observed from the eyepiece

② When observed on a monitor


The focus of both of the above is often not the same.


If each is individual, just adjust the microscope up and down.

Focus can be adjusted.




・The point of matching is the C mount on the microscope side.

The C-mount eyepiece tube on the microscope side comes in various types from different manufacturers, but as long as it’s a C-mount, any of them should not affect the focusing adjustment.




However, the choice of C-mount eyepiece can affect the field of view. On the C-mount side, the magnification affects the field of view as follows:

– Higher magnification → Narrower field of view
– Lower magnification → Wider field of view


▼Example of changing only the C-mount magnification without changing anything about the microscope body





・C-mount that can match focus

If you absolutely need to align the focal plane of the C-mount with that of naked eye observation, it’s advisable to choose a C-mount eyepiece with built-in fine adjustment capabilities. For example, with Olympus, you might opt for one that comes with the “Focus LOCK” feature.





Additionally, there are non-OEM (Original Equipment Manufacturer) C-mount adapters available for sale, such as the ones listed below.













Comparison of field of view between stereo microscope and autofocus microscope

The practical field of view of the autofocus digital loupe is almost the same as the NSZ405 stereo microscope with a 0.5x auxiliary lens attached.

(In terms of the total magnification of a stereo microscope, it is 3.5 to 15 times.)




The autofocus loupe has a focal length of 150mm.




Stereo microscope NSZ405 is equipped with a 0.5x auxiliary lens (WD180mm)


実体顕微鏡 NSZ405は0.5倍の補助レンズを装着 実体顕微鏡 NSZ405は0.5倍の補助レンズを装着


■Autofocus digital loupe


・Set optical zoom to “5.5”




・Set optical zoom to “14”



・Set optical zoom to “14” and digital zoom to “1.7”

*Digital zoom “1.7” is practical range

光学ズーム「14」 デジタルズーム「1.7」に設定


■Stereomicroscope NSZ405 + 0.5x auxiliary lens

・Objective lens set to “0.7”


実体顕微鏡 NSZ405 + 0.5倍補助レンズ


・Objective lens set to “1.5”


対物レンズ 「1.5」に設定


・Set objective lens to “3.0”




In terms of total magnification of a stereo microscope, it is a microscope that covers an area of ​​3.5x to 15x.

Pretreatment for metallographic observation and measurement




1. What is pretreatment for observing and measuring metal structure?


Pretreatment is required to observe the metallographic structure using a microscope.
Broadly speaking, the following four types of pretreatment are common.

2. Each pretreatment method


①Sample cutting
A large sample specimen is cut into small pieces using a cutting machine.



②Resin embedding
The cut sample is hardened with resin.

The reasons and purposes for embedding it in resin are as follows.


・Maintenance of sample edge shape
・Holds the shape of the sample so that it does not deform.
・Create a flat shape that is easy to observe


<Representative resins>


·acrylic resin
・Bakelite resin
·Epoxy resin
・Melamine resin




Each resin has different properties and colors, as well as different curing methods.
There are various types such as thermoplastic, thermosetting, natural curing, UV light irradiation curing, and two-component mixture curing.


The sample is placed in a cylindrical case and hardened with resin.
For heat curing, use a heating embedder, and for UV light curing, use UV light.

It may be omitted depending on the observation target.



③ Grinding and Mirror Finishing

The surface of the metal sample specimen is polished.
Generally, a grinding machine is used.
There are manual and automatic types of grinding machines, with the former being suitable for experts and the latter for beginners.
The manual type is prone to uneven polishing due to the force applied by hand to hold the sample, making it suitable for experts.
The automatic type, when the sample specimen is fixed to the sample fixing fixture, automatically polishes it, making it less prone to uneven polishing and suitable for beginners.

Rough polishing to precision polishing of the sample specimen is done using waterproof abrasive paper.
Polishing is done in wet conditions (while dripping water) from coarse to fine.
In precision polishing, the sample is finished to a mirror surface using cloth or buff polishing, diamond slurry, alumina powder, etc.
Therefore, it is necessary to change the grit of the waterproof abrasive paper many times.
There are single-layer and double-layer types of grinding machines, with the double-layer type being more expensive but convenient.

Once the mirror surface is achieved, the specimen surface is washed with flowing water.
After washing, it is dried using a dryer or similar equipment.



④ Etching Treatment (Surface Corrosion)

The polished surface of the sample specimen is immersed in etching solution (corrosive solution) suitable for the material and properties of the sample.
Etching treatment is performed for a duration that corresponds to the concentration of the etching solution and the material and properties of the sample specimen.

Example: For graphite spheroidization, a 3% nitric acid alcohol solution (Nital solution) is used.

After etching, rinse the sample specimen with water to remove the etching solution, then clean with ethyl alcohol or similar solvent before drying with a dryer or similar equipment.



Graphite spheroidization rate before etching

Graphite spheroidization rate after etching

3. Microscopic observation of metal structure


After undergoing the aforementioned pre-treatment processes, the metal structure can finally be observed. The polished mirror surface of properly pre-treated sample specimens is observed under a microscope. By enlarging the structure and adjusting the focus, the metal structure is observed.

At our company, we offer “metal microscopes,” “microscope USB cameras,” and “sets combining metal microscopes and cameras.” Please refer to the following for product details.


However, for advanced measurements such as observing non-metallic inclusions, measuring graphite spheroidization rates, and analyzing grain sizes (ferrite grain size, austenite grain size), specific measurement methods and counting techniques are utilized.

Observing metal structures requires appropriate pre-treatment processes, which can be time-consuming and labor-intensive. Therefore, it is recommended to efficiently perform these tasks in a shorter time frame using dedicated software.

How to clean lenses and filters

This section describes how to clean the lens and filter.

Dust, dirt, dust, dirt, fingerprints, etc. adhere to lenses and filters.


In that case, please follow the steps below to clean it.


~Things to prepare~

・Commercially available lens blower

・Commercially available lens cleaning tissue, paper, or lens cleaning swab

(Things that do not or generate little dust)

・Commercially available lens cleaning liquid or high purity ethanol


There are also products that include all of the above in one set.





Products from KING (Asanuma Shokai Co., Ltd.)

camera cleaning kit




【please note】

You can also use canned air duster instead of a blower.

Some of those canned air dusters emit small water droplets.

Avoid this type when cleaning lenses and filters.




(1)Use a blower to blow away coarse dust from the lens and filter surfaces.

【please note】

If you wipe with dust still attached, it may damage the lens surface or damage the lens surface.

The coating may peel off. Please blow it away enough.





(2) Wrap lens cleaning paper around a chopstick, etc.

【please note】

You can use tweezers instead, but the paper will tear and the metal will come into direct contact with the lens, damaging the lens surface or peeling off the coating on the lens surface.

Avoid using metal tweezers or the type with sharp tips.





(3)Add a few drops of cleaning solution to the wrapped cleaning paper to dampen it.


(4)Wipe the lens surface.

At this time, there are two methods: wiping radially from the center to the periphery, and wiping in a spiral pattern from the center to the periphery. Please use them depending on the direction of the dirt.

【Please note】

Please wipe it gently at this time. If you wipe too hard, the coating on the lens surface may peel off.






(5)Wipe dry if there are any remaining water droplets.

【please note】

Please wipe it gently at this time. If you wipe too hard, the coating on the lens surface may peel off.

Color? Monochrome? How to Choose a High-Speed Camera

Shodensha’s low-cost high-speed camera achieves filming at up to 1000 frames per second, all for just around 200,000 yen. We offer both monochrome and color options, both at the same price.


There’s often a misconception that if color is available, monochrome isn’t necessary. However, monochrome cameras have their own advantages. Firstly, since they don’t use RGB, their sensitivity is exceptionally high. They can even capture footage at 800 frames per second under fluorescent lighting (although flickering may occur depending on the type of fluorescent light). Additionally, monochrome footage has smaller file sizes compared to color, allowing for longer recording times.


If you absolutely need to determine the color of the subject, then color is necessary. However, if color isn’t particularly important, monochrome is recommended.

Furthermore, traditional high-speed cameras required storing footage in the camera’s internal memory, which limited recording time. Our new cameras don’t have built-in memory; instead, they use the computer’s memory for recording. This means that the more memory your computer has, the longer you can record. Additionally, we offer optional long-duration recording software, allowing for recording by the minute or hour.


We also offer demo units for lending, so if you’re interested, please don’t hesitate to contact us anytime.

Must-See! How to Choose a High-Speed Camera

High-Speed Camera


“High-speed cameras are those capable of capturing footage at frame rates exceeding the standard video frame rate (30FPS). In other words, they are cameras used to capture high-speed phenomena. While there isn’t a precise definition, high-speed cameras typically have frame rates of 100FPS or higher. There is a wide variety of manufacturers and models of high-speed cameras available, ranging from high-grade specifications to expensive models costing millions of yen. So, what criteria should you consider when purchasing a high-speed camera?”


Selecting a High-Speed Camera: What Information Do You Need?


When it comes to selecting a high-speed camera, what information is essential? While we’ve discussed frame rates earlier, that’s not the only necessary piece of information.

You’ll also need details such as ‘frame rate (speed),’ ‘resolution,’ ‘recording time,’ and whether the camera is ‘monochrome or color.’

Let’s dive into each of these factors in the following sections.


Selecting a High-Speed Camera: Frame Rate (Speed)

When it comes to high-speed cameras, different manufacturers and models offer various maximum frame rates (FPS) that they can achieve. Generally, as the frame rate increases, so does the price.

For example, if the desired phenomenon to capture requires a higher speed than what the camera can provide, capturing it effectively becomes challenging. On the other hand, if the camera’s frame rate is too high, it becomes overkill and unnecessarily expensive.

So, what frame rate (speed) of a high-speed camera should you choose? It’s crucial to ensure that the camera’s frame rate covers the speed of the high-speed phenomenon you want to capture.   


Selecting a High-Speed Camera: Resolution

High-speed cameras come in various maximum resolutions (in pixels). Generally, as the maximum resolution increases, so does the price. Additionally, higher resolutions result in larger data sizes, which can lead to shorter recording times.

So, what resolution of a high-speed camera should you choose?

It’s essential to consider what you’ll do with the footage after capturing it. This includes tasks like ‘video storage,’ ‘frame-by-frame playback,’ ‘extracting and saving still images,’ and ‘software analysis and evaluation for motion analysis or fluid dynamics.’

For instance, if you require detailed analysis and evaluation after capturing, you might opt for a higher resolution. Conversely, if the resolution is higher than what you need, it becomes overkill and unnecessarily expensive.

The resolution you need depends on what you plan to do after capturing the footage. It’s crucial to ensure that the required resolution falls within the camera’s maximum resolution. Additionally, if the camera allows for selecting resolution within its maximum resolution, choose the resolution appropriate for your shooting needs.

Selecting the highest resolution can lead to unnecessary data sizes, resulting in slower frame rates (speed) during shooting or shorter recording times.

In reality, the required frame rate (speed) and necessary resolution are closely related and affect the recording time. If you find it challenging to compare different manufacturers and models, it’s recommended to compare and select based on VGA (640×480) resolution.


Selecting a High-Speed Camera: Recording Time


High-speed cameras are available in monochrome and color options. While there’s often a preference for color, monochrome cameras actually produce cleaner footage. If color information isn’t necessary for analysis, evaluation, or assessment, I recommend choosing a monochrome camera. Monochrome footage not only looks cleaner but also tends to be brighter compared to color footage, resulting in smaller file sizes.


In conclusion, the key information needed when selecting a high-speed camera includes ‘frame rate (speed),’ ‘resolution,’ ‘recording time,’ and ‘monochrome or color.’ These four factors are closely related and essential when choosing a high-speed camera. Additionally, factors such as lighting, lens selection based on shooting distance and magnification, and choosing image recording media and methods also play crucial roles.

If you encounter any difficulties in selecting a high-speed camera or related equipment, please don’t hesitate to contact us. When doing so, please provide the following information:

– What is the subject of the shooting?
– How large is the subject?
– How fast is the subject moving?
– What is the distance from the subject to the lens?
– How long of a recording time is needed?
– Monochrome or color?
– What do you want to do after capturing the footage?

Regarding long-duration recording with high-speed cameras:

Standard software cannot handle long-duration recording.

High-speed camera footage contains a high number of frames, resulting in significant data volume. Additionally, fast data writing speed is required.


In terms of capacity, it is necessary to write directly to hard disks or SSDs to keep up. Furthermore, considering writing speed, a high-performance PC combined with an SSD is required. However, depending on the SSD product, if about half of the capacity is used, the writing time may drop significantly, so it’s important to carefully select the components.


For long-duration recording, it’s essential to consider both the software and hardware aspects.


In our company, we provide a set consisting of a high-performance PC with SSD, camera, and custom recording software, verified for operation. (Recording time varies depending on SSD capacity, high-speed camera speed, and resolution.)


However, when combining a high-speed camera (CHU130EX) with an SSD-equipped high-performance PC and long-duration recording software, the cost will be approximately 1.2 to 1.3 million yen.

Về việc ghi hình lâu dài bằng camera tốc độ cao

Khi xem xét về việc ghi video trong thời gian dài bằng camera tốc độ cao, có hoặc không có bộ đệm trên máy ảnh sẽ quyết định nhiều.

camera tốc độ cao CHU130-EX của Matsuden có bộ nhớ ghi video tích hợp dung lượng 2GB.

Trong trường hợp camera tốc độ cao không có bộ đệm, hình ảnh từ máy ảnh sẽ được ghi trực tiếp vào RAM (Bộ nhớ) của PC, và sau đó sẽ được lưu trữ trên HDD hoặc ổ SSD.

Tóm lại, khả năng ghi video trong thời gian dài phụ thuộc vào sự cân bằng giữa dung lượng RAM của máy tính và tốc độ ghi của ổ HDD.

Nếu tốc độ ghi vào HDD chậm, bộ nhớ có thể bị tràn.

Đối với các giải pháp, bạn có thể:

– Tăng dung lượng RAM trên máy tính.
– Sử dụng ổ SSD thay vì HDD.
– Để ý rằng, việc thử nghiệm cùng với máy tính là cần thiết để đánh giá thực tế.

Thông tin thêm, về việc ghi video với độ phân giải 130 vạn điểm ảnh (1280×1024) trong 15 phút sẽ tạo ra một tập tin có dung lượng 120GB.

Recording a 24-hour video with a video microscope

When recording for extended periods like 24 hours, using a hard disk recorder with a video microscope makes it straightforward to achieve long-duration recordings.

For example, with a 2TB (terabyte) hard disk, you can record for more than 10 days continuously.


The terminals compatible with attaching to the hard disk include BNC connectors as well.


It is also possible to convert the video terminal to USB and directly save the video to a PC. In this case, as a guideline, the file size will be approximately 1MB per second for VGA (640×480) resolution. Therefore, you will need to prepare an HDD or SSD with a capacity that accommodates the required recording time. We can also assist you with recommendations for suitable hard drives. Please feel free to contact our technical support for assistance.

What is vignetting?

What is vignetting?
A black tunnel-like area that occurs when a lens that is incompatible with the camera’s image sensor is used.
It will look like you are looking through a tunnel.



ケラレ Black areas (vignetting) can be seen at the four corners of the screen. 



Cause of vignetting


●If the camera sensor size is larger than the compatible camera sensor inch of the lens


●For borescopes
The wider the sensor size of the camera connected to the borescope, the wider the vignetting area. 

On the other hand, the image is closer to what you would see directly through a borescope.


●For microscopes

Usually, microscope cameras are made to avoid vignetting (shadows at the four corners).

We design with a margin to avoid vignetting, but the degree of vignetting varies depending on the manufacturer.

How to program our industrial UVC camera using Python

Python is a programming language known for its simplicity, rich libraries, cross-platform compatibility, open-source nature, and versatility. Here are some key features:

1. Simple Syntax: Python’s syntax is straightforward and easy to read, making it accessible even to programming beginners.

2. Rich Libraries: Python boasts a vast array of libraries that enable easy execution of various tasks across different domains.

3. Cross-Platform: Python runs on various platforms, including Windows, Linux, and macOS, ensuring broad compatibility.

4. Open Source: Python is open-source and freely available for anyone to use, contributing to its widespread adoption.

5. Versatile Use: Python is suitable for a wide range of applications, including web development, data analysis, machine learning, artificial intelligence, automation, and game development.

Given these characteristics, Python is widely used by both beginners and professionals for various development purposes.

To utilize our UVC camera and capture video using Python, you can execute the following code:

How to capture long-duration videos using a high-definition camera

When it comes to recording long-duration videos lasting several hours with a high-definition camera, there are primarily two approaches: using a computer (PC) and not using a computer.

Using a computer allows direct recording of videos onto the PC’s storage, facilitating extended recording sessions. For details on how to utilize a computer for this purpose, please refer to the following page.


If you’re not using a PC, another option is to use our HDMI recorder with an external HDD connected to it.


You can achieve long-duration recording by connecting a high-capacity external HDD (up to 1TB) instead of a USB flash drive.

Please note that externally powered HDDs are required as bus-powered external HDDs will not function properly.


Moreover, ensure that the HDD is formatted in NTFS format for recording long videos as FAT32 has a file size limit of 4GB per file. exFAT format is not supported for this purpose.

If you want to use an industrial camera on Linux

■ The Genesis of Linux
Linux, unlike Windows, comes in various distributions.

Linux distributions can be developed and distributed freely by anyone, allowing individuals, small groups, and even corporations to provide distributions tailored for different hardware and purposes.

Popular distributions for personal computers and servers include “Debian GNU/Linux,” “Ubuntu,” “CentOS,” “Raspbian,” and “Fedora.”

However, not all applications are compatible with every distribution.

Below, we outline the process of using our cameras with Linux.

■ Using Industrial UVC Cameras
UVC cameras are compatible with many distributions.

Many Linux distributions already have UVC camera drivers built-in.

Additionally, the OpenCV image processing library supports UVC cameras, making it much easier to program compared to industrial USB3 Vision / GigE Vision cameras.

Traditionally, UVC cameras have been associated with built-in lenses, mass production, and low-cost sales akin to webcams. However, our company offers cameras with external terminals (trigger terminals) and interchangeable C-mount lenses.