1．Methods of Lateral Viewing with a Borescope

There are primarily two methods of lateral viewing using a borescope. I will introduce the characteristics of each method.

◆ Utilizing a lateral (90°) viewing borescope

The lateral viewing type of borescope, characterized by an optical path arranged in a single direction, may exhibit uneven brightness across the observed surface due to its directional lighting configuration.

The optical path is arranged unidirectionally.		Imbalance in brightness occurs across the observation surface

Additionally, since the illumination is not ring-shaped but directional, uneven brightness may occur on the screen when observing reflective objects.

◆ Covering a direct-view borescope with a side-view tube (side-view adapter).

– A side-view tube (side-view adapter) is an accessory designed for enabling lateral viewing with a direct-view borescope. Simply fitting it over the tip allows for easy lateral observation.

– Note: The diameter of the side-view tube (side-view adapter) for a φ4mm borescope is φ5.5mm, which makes it slightly thicker.

– Image of a Side-View Tube (Side-View Adapter) Installation

– The advantage of the side-view tube (side-view adapter) is that it can be rotated while attached, allowing for easy observation of a 360° field of view.

– The disadvantage is that the edges of the mirror are visible, preventing the use of the entire field of view.

– Using a direct-view type results in ring-shaped illumination. Additionally, the mirror is more susceptible to the effects of dust and dirt (reflections).。

2． When connecting a camera to a borescope.

– When connecting a camera, the differences in this method significantly impact the results, as cameras generally have a lower dynamic range than the human eye.

– Advantages and Disadvantages of Lateral Viewing Type	– Advantages and Disadvantages of Direct-Viewing Type
– Bright and dark areas occur on the same surface. – In the presence of lateral holes, the walls and bottom surfaces of these holes will be shadowed.	– When observing the same surface, the central area appears bright while the periphery remains dark. – Light also reaches the walls and bottom surfaces of lateral holes. – The edges of the mirror are reflected in the view. – The attachment and removal of the side-view tube allow for both direct and lateral observation.
– However, depending on the reflectivity and shape of the object, the lateral viewing type may provide a clearer view.
＜Lateral Viewing Type＞ ・The observation surface is easier to see.。	＜Direct Viewing Type with Side-View Tube＞ ・Illumination is reflected in the central area.

3. Recommended Camera Feature for Borescope Observation: “WDR (HDR)”

Our company recommends cameras with WDR (HDR) functionality for borescope use.

WDR (HDR) stands for Wide Dynamic Range (High Dynamic Range), a feature that expands the camera’s dynamic range.

Below is an image taken with a camera equipped with WDR functionality connected to a side-view type borescope.

The “Lateral Viewing (90°) Type” and “Direct Viewing Type” borescopes introduced here are available through our company.

For more details, please visit the product pages below.

<SAMPLE>

Given the difficulty in obtaining engine cylinders, we conducted tests using aluminum cans for this study. The dimensions of the aluminum can were φ100mm×H130mm. We inscribed numbers from 1 to 5 on the interior wall and introduced several scratches in various locations.

<CAMERA>

Methods 1 to 5 utilized our company’s full high-definition camera. The details of the camera used can be found here. By standardizing the camera, we were able to conduct a pure comparison of lenses. Additionally, for method 6, we employed an S-mount UVC camera as an additional edition.

1. Method for inspecting the entire circumference of the inner wall in one shot using a wide-bore scope.

1. Wide-bore scope: φ4mm
2. Flat dome-type illumination: DC-30D-127W-CH1
3. Illumination for borescope: LED-3WDB

		Left: Scene of the capture Right: Magnification of the insertion part The borescope can be observed slightly protruding from the entrance of the can. Due to the distance and proximity to the bottom, visibility of scratches near the depths is reduced.
		The borescope was positioned slightly away from the entrance to capture the entire area within a single frame.
		To magnify the view, the borescope was slightly inserted from the entrance and captured.

The operability is rated at ★4 due to the ability to confirm the entire circumference of the inner wall in one shot.

The visibility level of scratches is rated at ★3.

2. Method for inspection using a 90° side-view borescope (φ4mm) (requires rotation of the bore).

1. Borescope: φ4mm, 90° side-view
2. Flat dome-type illumination: DC-30D-127W-CH1
3. Illumination for borescope: LED-3WDB

		Scene of the capture: The borescope is inserted into the can. Rotating the bore is necessary for complete circumference inspection (requires rotating the camera). Additionally, during magnification, the entire top-to-bottom view cannot be observed in a single frame, necessitating vertical movement.
		To ensure the entire height fits within one frame, the borescope was positioned slightly away from the inner wall for the capture.
		To magnify the view, the borescope was brought close to the inner wall for the capture.

Rotating the bore is necessary for inspecting the entire circumference of the inner wall, requiring rotation of the camera itself, resulting in a usability rating of ★2.

The visibility level of scratches is rated at ★4.

3. Method for inspection using a 90° side-view (interchangeable tip) rotatable borescope (φ8mm) (requires rotation of the bore).

1. Rotatable borescope (interchangeable tip): φ8mm, 90° side-view
2. Flat dome-type illumination: DC-30D-127W-CH1
3. Illumination for borescope: LED-3WDB

		Scene of the capture: The borescope is inserted into the can. While rotation of the bore is necessary for complete circumference inspection, the rotatable borescope features an interchangeable tip that allows rotation of the tip tube, eliminating the need for camera rotation.
		The borescope was positioned away from the inner wall for the capture, but capturing the entire top-to-bottom view in one frame proved challenging, necessitating slight vertical movement.
		To magnify the view, the borescope was brought close to the inner wall for the capture.

For inspecting the entire circumference of the inner wall, rotation of the bore is unnecessary with the rotatable borescope. However, vertical movement is required, resulting in a usability rating of ★3.

The visibility level of scratches is rated at ★4.

4. Method for inspecting the entire circumference of the inner wall in one shot using a microscope for observing hole walls.

　1. Microscope for observing hole walls (for diameters ranging from φ20mm to φ120mm): PH200BA-D30

		Left: Scene of the capture Right: Product photograph
The lens is positioned near the entrance (no need to insert into the can), allowing for a complete circumference inspection of the can interior in one shot. Visibility is reasonably good. Since there’s no need to insert the lens portion into the can, the risk of damaging the sample is low.
		To ensure the entire area fits within one frame, the lens was positioned slightly away from the entrance for the capture.
		To magnify the view, the lens was positioned at the very edge of the entrance, but it’s not particularly suited for magnification.

Operability is rated at ★4 due to the ability to confirm the entire circumference of the inner wall in one shot.

The visibility level of scratches is also rated at ★4.

5. Method for inspection using a high-magnification lens with a 90° side-view mirror attached to the tip (requires rotation of the lens).

1. High-magnification lens: FZ lens
2. Custom-made 90° side-view mirror attached to the tip of the lens
3. Custom-made LED illumination for attaching the 90° side-view mirror

		Left: Scene of the capture Right: Magnification of the insertion part The lens is fully inserted into the can for observation.
		Minimum magnification: Approximately 40 times
		Maximum magnification: Approximately 200 times

Mainly focused on magnified observation, the visible area at once is narrow, making it difficult to navigate, resulting in a usability rating of ★1.

The visibility level of scratches is rated at ★5.

However, it’s worth noting that for scratch detection purposes, this method may not be practical, and it’s primarily intended for magnified observation purposes.

6. [Special Edition] Method for inspecting the entire circumference of the inner wall in one shot using an S-mount camera and fisheye lens.

　1. UVC camera
2. Fisheye lens
3. Flat dome-type illumination: DC-30D-127W-CH1

		A fisheye lens is attached to a tube camera with interchangeable lenses. This allows for both direct viewing and side-view observation simultaneously.。
* With a lens diameter of 28mm, unlike borescopes, it cannot observe narrow objects. * Additionally, it is not suitable for deep holes.
		Capturing the image slightly away from the entrance of the can.
		Capturing the image right at the entrance of the can.

Operability is rated at ★4 due to the ability to confirm the entire circumference of the inner wall in one shot.

The visibility level of scratches is rated at ★3.

However, it’s worth noting that the visibility can vary significantly depending on how the lighting is applied, resulting in extreme contrasts between bright and dark areas.

<Summary>

When observing inner walls, it’s essential to select a camera system that aligns with your budget and intended purpose.

Considering usability is also recommended during the evaluation process.

Selecting a camera system based on your specific application. Recommended camera systems:

If you aim to inspect the entire circumference of the inner wall in one shot for scratch detection purposes:

4. Method for inspecting the entire circumference of the inner wall in one shot using a microscope for observing hole walls.

– The PH200BA-D30 microscope for observing hole walls (for diameters ranging from φ20mm to φ120mm) is recommended.

If you desire magnified observation of scratches:

5. Method for inspection using a high-magnification lens with a 90° side-view mirror attached to the tip (requires rotation of the lens) is recommended.

If you want to ensure comprehensive observation without missing any area in the 90° inner wall direction:

3. Method for inspection using a 90° side-view (interchangeable tip) rotatable borescope (φ8mm) (requires rotation of the bore) is recommended.

– The components mentioned, including the interchangeable tip rotatable borescope (φ8mm, 90°), flat dome-type illumination (DC-30D-127W-CH1), and illumination for borescope (LED-3WDB), are recommended.

If you want to observe both the bottom and inner walls with a single device:

1. Method for inspecting the entire circumference of the inner wall in one shot using a wide-angle borescope is recommended.

If price is a primary consideration:

6. [Special Edition] Method for inspecting the entire circumference of the inner wall in one shot using an S-mount camera and fisheye lens is recommended.

I’ve summarized the camera systems that can be used for inspecting engine cylinder walls or can walls. I’ll introduce them with actual images, as well as their respective merits and drawbacks.

●Test conditions

<Sample>

Since engine cylinders are difficult to obtain, we conducted the test using aluminum cans this time.
The size of the aluminum can is φ100mm × H130mm.
We marked numbers 1 to 5 on the inner wall.
We made scratches in several places.

<Camera>

Methods 1 to 5 used our full high-definition camera. ⇒ Camera used here
By using the same camera, we can compare the lenses purely.
*For method 6, we used an S-mount UVC camera as a special edition.

●Inspection Method and Results

1.　Method for inspecting the entire circumference of the inner wall in one shot using a wide bore scope

　①ワイドボアスコープ　φ4mm　ボアスコープ　0°
　②平型ドーム式照明　DC-30D-127W-CH1
　③ボアスコープ用照明　LED-3WDB

		Left: Shooting Scene Right: Insertion Port Enlarged The borescope can be observed slightly away from the entrance of the can. There is a distance, and scratches close to the bottom are less visible.
		The borescope is positioned slightly away from the entrance to capture the entire area in a single frame.
		Position the borescope slightly inside the entrance to capture an enlarged view.

The operability is rated at ★4 since the entire circumference of the inner wall can be checked in one shot.

The visibility level of scratches is rated at ★3.

Method 2: Inspection using a 90° side-view borescope (φ4mm) (Requires bore rotation)

　①ボアスコープ　φ4mm　ボアスコープ　90°

　②平型ドーム式照明　DC-30D-127W-CH1

　③ボアスコープ用照明　LED-3WDB

		Shooting Scene The borescope is inserted into the can. Rotating the bore is necessary to inspect the entire circumference (requires rotating the camera along with the bore). Additionally, when enlarging, the top and bottom cannot be observed in a single frame, requiring vertical movement as well.
		Position the borescope slightly away from the inner wall to capture the entire height in a single frame.
		Bring the borescope close to the inner wall to capture an enlarged view.

If inspecting the entire circumference of the inner wall, bore rotation is necessary, requiring rotation of the camera as well, thus rated at ★2 for operability.

However, the visibility level of scratches is rated at ★4.

３.　Method: Inspection using a 90° side-view (interchangeable tip) swivel borescope (φ8mm) (Requires bore rotation)

　①（先端交換式）くるっとボアスコープ　φ８㎜　90°

　②平型ドーム式照明　DC-30D-127W-CH1

　③ボアスコープ用照明　LED-3WDB

		Shooting Scene The borescope is inserted into the can. To inspect the entire circumference, bore rotation is necessary, but since it’s a swivel borescope, the tip tube can be rotated. (Camera rotation is not required)
		The borescope was positioned away from the inner wall for the shot, but capturing the top and bottom in a single frame is not possible, so some vertical movement is required.
		Bring the borescope close to the inner wall to capture an enlarged view.

If inspecting the entire circumference of the inner wall, a swivel borescope eliminates the need for camera rotation, but vertical movement is necessary, rated at ★3 for operability.

However, the visibility level of scratches is rated at ★4.

４.　Method: Inspecting the entire circumference of the inner wall in one shot using a microscope for observing hole walls

　①穴内壁観察用マイクロスコープ（φ20mm～120mm用） PH200BA-D30

		Left: Shooting Scene Right: Product Photo
The lens is positioned near the entrance (no need to insert into the can) to allow for a one-shot inspection of the entire circumference inside the can. Visibility is reasonably good. Since there’s no need to insert the lens portion into the can, the risk of damaging the sample is low.
		Position the lens slightly away from the entrance to capture the entire area in a single frame.
		Capture the image with the lens positioned right at the entrance, allowing for maximum magnification. However, it’s not particularly suitable for significant magnification.

Operability is rated at ★4 since the entire circumference of the inner wall can be checked in one shot.

The visibility level of scratches is also rated at ★4.

５.　Method: Inspection using a high-magnification lens with a 90° side-view mirror attached to the tip (Requires lens rotation)

1. High-magnification lens: FZ lens
2. Custom-made: 90° side-view mirror attached to the tip of the lens
3. Custom-made: LED illumination for attaching the 90° side-view mirror

		Left: Shooting Scene Right: Insertion Port Enlarged The lens is fully inserted into the can for observation.
		Minimum magnification: Approximately 40x
		Maximum magnification: Approximately 200x

Operability is rated at ★1 because the main focus is on magnification, and the visible area at once is narrow, making it difficult to search.

However, the visibility level of scratches is rated at ★5.

It’s worth noting that while it’s not very practical for scratch detection purposes, it’s primarily intended for magnification observation.

。

６.　[Special Edition] Method for inspecting the entire circumference of the inner wall in one shot using an S-mount camera and fisheye lens

1. UVC camera
2. Fisheye lens
3. Flat dome-type lighting DC-30D-127W-CH1

		Attach a fisheye lens to a tube camera with interchangeable lenses. This allows for side-view observation while maintaining direct viewing.
* Since the lens diameter is 28mm, it cannot observe small-diameter objects like borescopes. It’s also not suitable for deep holes.
		Capture the image with the camera positioned slightly away from the entrance of the can.
		Capture the image with the camera positioned right at the entrance of the can.

Operability is rated at ★4 since the entire circumference of the inner wall can be checked in one shot.

The visibility level of scratches is rated at ★3.

However, the visibility greatly varies depending on how the lighting is applied, resulting in extreme differences between bright and dark areas.

Summary:

When observing inner walls, it’s essential to choose a camera system that fits your budget and purpose.

Considering operability is also recommended during the evaluation process.

Recommended camera systems to choose from based on usage

<If you want to check the entire circumference inside the can in one shot for the purpose of finding scratches>

4. Method for inspecting the entire circumference of the inner wall in one shot using a microscopewith an aperture wall observation function.

① The aperture wall observation microscope (for φ20mm to φ120mm) PH200BA-D30 is the best option.

<If you want to magnify the scratches>

5. Method for inspecting using a high-magnification lens with a 90° side-view mirror attached to the tip (Requires lens rotation) is the best option.

<If you want to ensure absolute visibility of the inner wall direction at 90° without missing anything>

3. Method for inspecting using a 90° side-view (interchangeable tip) swivel borescope (φ8mm) (Requires bore rotation)

① (Interchangeable tip) Swivel borescope φ8mm 90°

② Flat dome-type lighting DC-30D-127W-CH1

③ Borescope lighting LED-3WDB is the best option.

<If you want to observe the bottom and inner walls with one device>

1. Method for inspecting the entire circumference of the inner wall in one shot using a wide-angle borescope is the best option.

<If price is a priority>

6. [Special Edition] Method for inspecting the entire circumference of the inner wall in one shot using an S-mount camera and fisheye lens is the best option.

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.
		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.

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.

Without cooling device

	120℃対応ボアスコープ（φ4.0mm） 製品詳細はこちらから   ●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)
	120℃対応ボアスコープ（φ2.7mm） 製品詳細はこちらから

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).

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

Without cooling device

	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)
	120℃ compatible borescope (φ2.7mm) Click here for product details

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).

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

■When using an f=16mm lens

Focal length approximately 35mm f=16mm lens + 5mm close-up ring

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

For more details, please visit the product page below

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

＜Reference＞

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.

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 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.)

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

[Attention]

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.

～Steps～

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

[Attention]

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

[Attention]

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.

[Attention]

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.

[Attention]

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

Telecentric lens

Telecentric lenses allow you to obtain images with less distortion.

I experimented with our telecentric lenses RT3 and RT5.

Telecentric lens RT3, RT5 Attach it to the USB camera. I took a photo of the glass scale.

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.

	I attached an 8mm fixed-focus lens to a USB camera and took a picture of graph paper.
	It is evident that the four corners of the graph paper are distorted.

	“I attached a 25mm fixed-focus lens to a USB camera and took a picture of graph paper.”
	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.

Summary:

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.

両側テレセントリックレンズ RT1 RT3 RT5

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. )

		テレセントリックレンズ（W.D.65mmタイプ）   テレセントリックレンズ（W.D.110mmタイプ）
		テレセントリックレンズ（同軸照明対応・W.D.65mmタイプ）   テレセントリックレンズ（同軸照明対応・W.D.110mmタイプ）
		メガピクセル対応テレセントリックレンズ（W.D.65mmタイプ）   メガピクセル対応テレセントリックレンズ（W.D.110mmタイプ）
		メガピクセル対応テレセントリックレンズ（同軸照明対応・W.D.65mmタイプ）   メガピクセル対応テレセントリックレンズ（同軸照明対応・W.D.110mmタイプ）

Special telecentric lens

■Long distance telecentric lens

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)

■Space-saving, high-magnification telecentric lens

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
(⇓Enlarge the red frame above)	(⇓Enlarge the red frame above)

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.

Summary

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.

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?

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.

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.)

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:

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 angle（LED-A2）	Mounting Example

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