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Screw diameter is exactly the same for C mount and CS mount.

It only differs from the back flange (the distance from the end of the lens to the image sensor).

CS mount is shorter by 5 mm.

Depending on the camera, 5 mm thick ring (C mount ring) may be attached to the tip to make C mount.

Therefore, if you remove C mount ring, it becomes CS mount.

This is image of C mount.

remove the c mount ring.

 

it will be cs mount.

C mount is a screw mount that fixes the camera and lens by screws.

Inner diameter 25.4 mm (1 inch), screw pitch 0.794 mm, flange back 17.526 mm is C mount standard

With the miniaturization camera, there is also a CS mount that reduces C flange back by 5 mm.

(The caliber and screw pitch are the same.)

 

 

Depending on the camera, 5 mm thick rings may be installed to both C mount and CS mount, so that It’s necessary they can be removed.

 

Summary 

 

Both C mount and CS mount can be mounted with the same aperture and screw pitch.

However, please take a note that the performance of the lens can not be fully demonstrated.

(The symptoms such as ” out of focus”, “the focal length fluctuates even though it is a zoom lens (* 1)”, “the magnification changes”, etc.)

(* 1) Please refer to “Macro lens and macro zoom lens”.

CMOS and CCD generally have the following differences.

However, CMOS function has improved recently, there is no clear difference.

 

<CCD is …>

1. CCD gives more natural color representation.
2. Shadow image clear
3. High price.
4. High power consumption.
   → It is difficult to achieve high resolution with battery operated digital cameras, video cameras, etc.
   (It does not much matter with USB camera for FA)

5. Partial readout of the image sensor can not be performed.
   → It is impossible to increase the display speed by lowering the resolution.(Therefore, there is no resolution changes in our CCD camera GR140CCD.)

 

<CMOS is …>

1. A little bit of blurring appears in the image and the clarity drops.
2. Cheap price
3. Partial readout of image sensor can be performed.
   If you reduce the resolution with CMOS camera, you can raise the display speed.

4. Vulnerable to movement
   Distortion (deformation) and afterimage will occur. It is a weak point of CMOS such as “dropping frames” or “awkward movement”.
   (It can be said to the rolling shutter type sensor in general.)

 

CCD（Global shutter）	CMOS（Rolling shutter）

 

Recently, the CMOS feature of the camera used in the industry has been enhanced.

In the past,

CMOS → rolling shutter → weak motion

CCD → global shutter → strong motion

The figure was completed.

Recently, there is a type of global shutter in CMOS to replace CCD.

Electricity is denoted by [VA] and [W]

 

Calculation for direct current:

Electricity (W) = voltage (V) × current (A)

Alternating current will change periodically not fix as direct current

Not all the product of voltage and current are consumed by the load.

 

For direct current, the power consumed purely by the load is called active power.

Active power (W) = Actual value of voltage (V) × Actual value of current (A) × Power factor (cos θ)

There is also power (reactive power) that does not actually work.

The power indication is called apparent power

Apparent power (VA) = actual value of voltage × actual value of current.

With standard software, you can not record for a long time.

 

The high-speed camera image has a large number of frames with very large capacity.

The high recording speed is also required

I think that I can not catch up unless I write directly to hard disk or SSD.

Since recording speed is also necessary, combining between high function PC and SSD is also required.

However, if you use about half of the capacity for SSD, the recording time will drop sharply. Therefore, it is very important what to choose.

In the case of long-time recording, you should to check not only software but also hard disks too.

 

At our company, we provide high function PC with built-in SSD, camera and recording software (custom order) as one set.

(Recording time also changes depending on the capacity of SSD, the speed of the high speed camera and resolution)

 

Combining high speed camera (CHU 130 EX), SSD built-in high function PC, long time recording software, the price is about 1.2 – 1.3 million yen.

Using buffer memory or not will much affect to long-term recording of high-speed cameras

Shodensha’s low price high speed camera has 2 GB memory for recording.

 

If you are using a high-speed camera without a buffer memory, the video captured by camera is written directly to RAM (memory) of the PC.

Tempoary video will be saved to HDD.

 

In conslution, the balance between HDD saving and PC memory is an important factor in whether long-time recording or not.

 

If the saving speed to HDD is slow, the memory will overflow.

 

・Equip as much memory as possible.

・It is necessary to equip SSD instead of HDD on PC.

 

It is necessary to evaluate with PC although there is a long-time recording software

In the case of purchasing a new PC, it is also possible to conduct experiments at our company.

 

Incidentally, if you record for 15 minutes with 1.3 million pixels (1280 x 1024), it will be a 120 GB file.

TILT is a method to adjust the depth of focus by tilting the optical axis of the lens.

It is possible to focus on the entire tilted object that does not parallel to the lens area.

 

The upper row connects to the lens as usual The optical axis is tilted in the lower row. (The connecting part is handmade)
Use these two types to look at the board.
< Normal shooting>	<Tilt shooting>

 

The mounting screws of most cameras are unified with tripod screws.

It usally called “Camera screw”, “tripod screw”

There are few differences between manufacturers and types of cameras.

 

The screw size is 1 / 4-20 UNC (1/4 inch coarse).

The screw diameter is about 6 mm.

There is no difference in single lens reflex cameras, small digital cameras, surveillance cameras, FA cameras..

The mounting screws shown in the bottom photo are all the same size.

 

 

With a small camera or an old camera, it may be used 3 / 8-16 UNC (3/8-inch coarse) The screw diameter is about 9 mm.

You can prepare a screw for camera fixing, but fixtures are also sold in various ways for both civilian and industrial.

Since the angle can be changed. Thus, it is one more way to use existing products.

 

Since it is a standard screw for the camera, you can use commercially available camera (tripod, pan head etc).

Since various conversion screws of 1/4-inch ⇔ 3/8-inch are available, tripods can be used even if the screw diameters are different.

 

 

Examples of camera fixing devices

Below is a part of LPL’s catalog.

・Examples of industrial camera fixtures

The following is a part of the catalog of SFC Co., Ltd.         

If the lens is long and heavy, there are also lens mounts

(All our lenses for microscope are φ50 mm (fixed part)

 

 

In camera function, we have Dynamic Range.

 

Dynamic range is the numerical value that represents the signal reproduction capability and the ratio between the minimum value and the maximum value in dB (decibel).

 

A camera with high value of dB is less prone to halation even if the object is bright and dark areas are less likely to shade. (High reproduction ability against changes in brightness.)

 

When viewing the interior of a metal workpiece like a borescope with a single lighting, the difference between the direct light and the shadow is large. The camera with a large dynamic range is more suitable for observation.

 

Normal C mount cameras can not be used for observation and monitoring in radiation areas such as nuclear facilities and laboratories.

In particular, it is necessary to use a sensor with radiation resistance performance for the imaging element.

Although it is not our product, it seems that the following radiation-resistant CMOS cameras are also on sale.

 

In order to perform UV observation (ultraviolet observation), it is necessary to have a UV (ultraviolet) sensitive camera and a UV compatible lens.

 

Shodensha cameras mainly observe visible light.

As picture shown below, there is no sensitivity in the ultraviolet region.

 

 

UV observation is divided into two types:

(1) Observe scratches, spots, irregularities on the surface of objects

(2) Observation of weak fluorescence phenomenon of objects

For cameras, you need to choose one of the following:

(1) A camera sensitive to ultraviolet rays. It is a camera like the one below.

 

 

(2) A camera is not merely an ultraviolet range. But an ultrahigh sensitivity camera is necessary to catch a weak fluorescence phenomenon. In general, I use a cooled CCD camera. It becomes the camera as follows.

 

For lenses, it is necessary to use UV-compatible lenses as below.

(The following is the zoom lens of Navitar USA)

 

Our camera has an infrared filter. Therefore, the screen in the infrared ares can not be taken.

However, depending on customer’s request, you can also create by removing the infrared filter. Please contact our technical advisor for more details.

There are monochrome (black and white) mode and pure monochrome in camera (black and white camera).

Either case may be good when used for applications such as contrast emphasis of edge noodles of observation objects.

Monochrome mode of color camera originally expresses color image in black and white

What is the advantage of a pure monochrome camera?

Generally, monochrome camera  is more sensitive than color camera

 

Higher sensitivity works well for adjusting the shutter speed and depth of focus.

Besides that, wavelength sensitivity characteristics are different.

The sensitivity of the sensor itself may not change very much.

　 　 　 　 　 　

Example of spectral characteristics for color camera	Example of spectral characteristics for monochrome camera
Example of filter characteristics for color camera

 

However, color cameras often contain filters. Thus, most of color cameras has the wavelength cut at about 650 nm.

When you attach the lens with the same magnification, the number of inches in the image size is smaller, the magnification and the narrower the field of view will be smaller.

 

Please see the picture below.

I shot the picture with lens, monitor, and focal length under the same conditions.

1/2 inch camera	1/2.5 inch camera	1/3 inch camera

 

You can realize that the 1/3-inch camera has a narrower field of view than the 1/2-inch camera.

Besides that, when selecting lenses, you need to check the size of the camera’s corresponding image sensor.

Please note that vignetting will occur if you select a lens that is less than the camera’s compatible image sensor size.

 

A black part (vignetting) is present at the four corners of the screen

We will also select lenses and cameras that is suitable for your requirements. Please contact our technical advisor for more details.

The specifications of C mount camera always include “image size” and “image sensor size”.

In addition, this size is the value needed to calculate the field of view (when selecting the lens).

(To calculation of field of view, please refer to “f value of lens”.)

 

 

The use of “image sensor size”

 

 

You can also calculate the size of one pixel.

For example: The image sensor of 1 / 2.5 inch of 1.3 million pixels (1280 X 1024) is:

Horizontal  5.6 mm / 1280 pixels = 0.0044 mm / dot

Vertical    4.2 mm / 1024 pixels = 0.0041 mm / dot.

 

Image Sensor Size Meaning

 

Typically, when referring to monitor sizes, it indicates the diagonal length. However, the size of an image sensor is not measured diagonally.

For instance, in the case of a previously mentioned 1/2.5-inch sensor with 1.3 megapixels, the horizontal dimension is 5.6mm and the vertical is 4.2mm, resulting in a diagonal length of approximately 7mm.

 

However, the actual 1/2.5-inch sensor measures 10.16mm diagonally. This discrepancy originates from the historical representation of imaging tubes using vacuum tubes, where the size indication was based on the diameter of these tubes. Consequently, the size representation of image sensors has been aligned with this convention.

 

The Actual image sensor size 

 

 

 

 

 

 

 

The practical use of imaging sensor size

The actual utilization of imaging sensor size pertains to the selection of the requisite lens and the calculation of the distance to the subject.

 

(1) In the case of CCTV lenses (fixed focal length lenses)

 

We shall calculate the required lens based on the desired dimensions of the subject to be captured. At this juncture, the essential factors are the “imaging sensor size of the camera” and the “distance to the subject (W.D.).”

 

 

 

 

 

If we aim to ensure a vertical field of view of 300mm at a distance (W.D.) of 1 meter, what focal length lens should be selected? Assuming the use of a 1/2-inch camera sensor, the dimensions are as follows:

Imaging sensor size for a 1/2-inch camera:

 

 

 

The formula for the f-value is as follows:

f-value = (Distance to the subject (mm) × Vertical size of the imaging sensor (mm)) / Vertical field of view

By substituting the values:

f-value = (1000mm × 4.8mm) / 300mm = 16mm

By selecting a lens with a focal length of 16mm, the desired vertical field of view can be achieved.

The calculation for the horizontal field of view can be done in a similar manner.

By the way, if either the vertical or horizontal field of view is known, the other can be easily calculated without additional computations.

For a square-shaped imaging sensor with a 4:3 aspect ratio, as in this case, the horizontal field of view would be 300mm × 4/3 = 400mm.

 

(2) In the case of macro lenses 

In the case of macro lenses used for capturing magnified images of subjects, the focal length is typically predetermined. In such instances, the f-value alone does not adequately represent the lens characteristics. Instead, the optical magnification is used as a measure.

For macro lenses, the optical magnification expresses the desired level of enlargement. With a lens at 1x (1:1 magnification), the observed field of view matches the size of the imaging sensor.

For example:
– For a 1/3-inch sensor, the dimensions are 4.8mm × 3.6mm.
– For a 1/2-inch sensor, the dimensions are 6.4mm × 4.8mm.

Considering these specifications, I recommend referring to our company’s macro lens specification sheet for more detailed information.

 

 

 

Additionally, when using a macro lens, the imaging sensor size is also utilized in calculating the overall magnification (the final magnification displayed on the monitor). The imaging sensor size plays a crucial role in determining the effective magnification of the captured image.

 

For more detailed information, I recommend referring to the concept of magnification in microscopes, as mentioned in the “Concept of Magnification in Microscopes” resource.

 

USB Camera CS series	USB Camera DN series	GigE Camera
1/1.1 inch	CS1200-GC（12MP・color） ／ CS1200-GB（12MP・monochrome）		EG1200-GC（12MP・monochrome）／ EG1200-GB（12MP・monochrome）
1/1.7 inch	CS1200-C（12MP・color） ／ CS1200-B（12MP・monochrome）		EG1200-C（12MP・color） ／ EG1200-B（12MP・monochrome）
1/1.8 inch		DN3RG-130（1.3MP・color） ／ DN3RG-130BU（1.3MP monochrome）   DN3RG-200（2MP color ） ／ DN3RG-200BU 2MP – monochrome	EG320-C（3.2MP color） ／ EG320-B（3.2MP monochrome）   EG600U-C（6MP color）／ EG600U-B（6MP monochrome）
1/2.3 inch		DN3R-1000（10MP color）
1/2.5 inch	CS500-C（5MP color） ／ CS500-B（5MP monochrome ）	DN3R-500（5MP color）
1/2.9 inch	CS41-C（0,04MP・color） ／ CS41-B（0,04MP・monochrome）		EG41-C（0,04MP・color） ／ EG41-B（0,04MP・monochrome）
1/2 inch	CS130U-C（1,3MP・color） ／ CS130U-B（1,3MP・monochrome）   CS500U-GC（5MP・color） ／ CS500U-GB（5MP・monochrome）		EG130U-C（1,3MP・color） ／ EG130-B（1,3MP・monochrome）
1 inch	CS2000-C（20MP・color） ／ CS2000-B（20MP・monochrome）		EG2000-C（20MP・color） ／ EG2000-B（20MP・monochrome）
2/3 inch			EG501-C（5MP・color） ／ EG500-B（5MP・monochrome）

Summary:

The imaging sensor size is a crucial value required for calculations such as “field of view” and “lens selection.” In the case of CCTV lenses, the f-value can be computed as follows to determine a lens that can achieve the desired vertical field of view:

f-value = (distance to the subject (mm) × vertical size of the imaging sensor (mm)) / vertical field of view.

For macro lenses, the imaging sensor size is utilized in calculating the overall magnification (the final magnification displayed on the monitor).

 

The phenomenon of flickering” refers to irregularities observed in footage captured by a camera, such as “repeated variations in brightness” and “shifts in color tone,” which are not perceptible to the naked eye.

In this article, we will provide an overview of “flickering phenomenon” and discuss methods to prevent it.

 

(1) WHAT IS FLICKERING?

 

 

The phenomenon known as “flickering” occurs with certain lighting devices that either flicker in sync with the power frequency or pulse in a dimming system.

Although the human eye cannot perceive the flickering of light, when the camera’s shutter speed is faster than the frequency of the flicker, it results in irregularities in the captured footage, such as “repeated variations in brightness” and “shifts in color tone.” This is referred to as the flickering phenomenon.

Flickering occurs under lighting conditions that involve periodic flashes, such as fluorescent lights, while it does not occur with direct current lighting.

There are two types of symptoms associated with flickering phenomenon:

1. In cameras with a global shutter, the entire image experiences cyclic changes in brightness.
2. In cameras with a rolling shutter, the image exhibits horizontal stripes of brightness variations, and these stripes may appear to flow vertically.

 

 

The phenomenon of “flickering” in cameras with a rolling shutter results in the appearance of horizontal stripes of brightness variations. 

 

 

 

 

Methods to prevent the phenomenon of flickering can be categorized into three primary approaches:

1. Utilize lighting devices employing direct current illumination.
2. Adjust the shutter speed to a pace slower than the flicker frequency.
3. Employ a camera equipped with the “flicker-free feature.”

 

 

1. Utilize lighting devices employing direct current illumination.

Flickering occurs in the presence of lighting sources that exhibit periodic emissions, while it does not occur when using lighting fixtures that operate on direct current illumination.

2. Adjust the shutter speed to a pace slower than the flicker frequency. 

 

The phenomenon of flickering can be somewhat mitigated by adjusting the exposure time or shutter speed settings of the camera, but it cannot be completely eliminated.

Even if it appears to have disappeared, there are still variations in brightness occurring at intervals of several tens of seconds or longer.

In particular, when capturing images with a high-speed camera under fluorescent lighting, significant flickering phenomena occur.

* If it is not possible to adjust the shutter speed on the camera, one can compensate for the reduced illumination by narrowing the aperture of the lens and using lighting fixtures with direct current illumination. This helps to comparatively reduce the impact of pulse lighting.

 

 

3. Employ a camera equipped with the “flicker-free feature.”

 

 The “flicker-free feature” enables the camera to automatically detect the flickering of the light source and capture images at optimal moments with minimal impact on brightness and color tones.

To avoid flickering phenomena, it is recommended to use lighting for high-speed cameras that either operate on direct current illumination or synchronize with the camera shutter, such as strobe lighting.

At our company, we offer a range of products including high-speed cameras, lighting specifically designed for high-speed cameras, and strobe lighting. If you are experiencing difficulties with flickering phenomena, please don’t hesitate to contact us for assistance.

Resolution means a numerical value indicating of pixels in a bitmap image. It is the fineness of the grid that expresses the image and it is represented how many pixels are divided in 1 inch.

For microscope, each camera, lens and monitor has different resolution.

1. Cameras and lens resolution are the detail of grid that represents the image.

It is a term that expresses the details of objects (screen, printed result, photographic film, etc.) that can define the size of the physical image.

Therefore, the physical resolution means the minimum unit that can be distinguished from the image (pixel, in the case of a printing result or photographic film, a line / space where the image can be resolved by a resolution chart) is determined per unit length of the object. It is expressed by the number that can be included and represents the definition level not the total number.

Camera and len resolution is very important in selecting resolution.

For example: If camera resolution is high and lens resolution is low, the image will be poor in resolution. Please be careful

2. What is monitor resolution?

Have a look at this. “about monitor resolution“

We will also select cameras and lenses. Please feel free to contact our Technical Advisor.

GigE camera is connected by LAN port.

However, there is no power supply line in LAN port attached to normal PC.

(Of course, power is necessary to operate the camera.)

 

There are two ways to use GigE camera.

1. Prepare individual separate power supply for camera.

2. Prepare NIC for PoE (Power over Ethernet) interface (LAN port with power supply line).

1.

There is no problem if an AC adapter is attached to the camera. But in order to connect between PC and camera, power support equipment is very necessary. It is called PoE injector. It can be obtained easily around 10,000 yen. It is possible to purchase with PC peripherals manufacturer (Elecom, Sanwa Supply, Buffalo etc.).

2.

NIC is short of Network interface card. NIC has the same meaning as the LAN board and indicates an expansion board. As mentioned above, there is no power supply line in the standard LAN port of a normal PC. Therefore, you need to add such an expansion board (card) to the PC.

 

When taking pictures by the camera, there are some cases which the part is too bright (halation / overexposed), and the part is too dark (blackened).

Dynamic range is called the range of contrast difference (defense range) which can be concealed at the same time to the edge before the halation (white jump) from black collapse (too dark to nothing). The unit is db (decibel).

The larger dynamic range number, the better camera.

However, when comparing human eyes and cameras, naked eyes are superior even with excellent cameras.

For example, even if you can see it with naked eyes, shooting with a camera may cause halation (white overexposure) or may not be visible.

It is a technique to express a wider dynamic range than normal image.

Reducing the contrast of the original image with large contrast and take a wide dynamic range.

Even with images with differences in brightness and darkness, it is possible to reduce blackout and whiteout.

The following is an excerpt from cameras specifications made by other companies, but WDR (wide dynamic range) has the same function.

 

There is what is called a dynamic range in the camera vocabulary. The dynamic range is the range of the brightest part and the dark part that the imaging element can feel.

 

If it exceeds this range on the bright side, it becomes halation (white jump).

The screen becomes black when exceeding this range in the dark.

 

HDR and WDR are functions that widen this range and reduce the difference between bright and dark areas. It is used for remove halation.

(However, if you use this function, the contrast will be lowered.)

 

For example: If you shoot a picture with differences in light and darkness, it will be like the picture below.

 

Normal function shooting	HDR function shooting

 

Our HDTV camera has HDR function.

By applying this, you can shoot images with reduced halation.

(It is an effect of widening the dynamic range. Although it does not make infinite, it can not be removed completely)

 

Normal function shooting	HDR function shooting
Normal function shooting	HDR function shooting

 

If this HDR function is combined with a filter and V character block, the performance will be further improved.

<HDR function + polarization filter>

<HDR function + White V character block (background)>

The size of the imaging element written in the specification etc. is not the actual diagonal dimension in notation following the “tube diameter” of the imaging tube age.

For example, 1/2 inch CCD means 「A CCD with the same image size as the image size produced by a 1/2-inch imaging tube」

However, the size will be confirmed with this notation.

If it is a 4: 3 elements, the size will be identified as below.

“CCD Camera image size”