The “Hole Inspection Lens PHL178” allows for 360° observation of the inner wall surface. Due to its compact size, the lens can be inserted into and used for inspection of holes with a diameter of φ45mm or greater.

Hole Inspection Lens PHL178

A black rubber sheet was attached to a cylindrical PVC pipe with a diameter of approximately φ100mm, and the inner wall was observed.

(Equipment used: Inner Wall Inspection Microscope PHL200BA)

▼camera setup

Since black rubber tends to absorb light, the image can easily become dark. However, by adjusting the lighting and camera settings, it was possible to observe with sufficient brightness.

Even if the light is insufficient, it can be brightened by modifying the illumination. We experimented by attaching commercially available LED tape lights to the side of the lens.

By using the Matsuden Corporation CS/EG series cameras, which are compact, the entire camera can be inserted into the interior, allowing for 360° observation of the inner wall.

The camera can be inserted into a cylinder with an internal diameter of φ45mm, enabling observation of the inner walls.

By manufacturing a jig for inserting the camera, it is possible to observe the inner walls of deep holes.

The endoscopic series of cameras for borescopes typically involve visual confirmation of the imagery on the main monitor. However, as the main unit outputs video signals (AV terminals), if a monitor with a 4:3 aspect ratio and video terminals is available, one can connect via a video cable to view the imagery on an external monitor.

During this process, visual confirmation of the imagery on the main unit’s monitor becomes unavailable. If one wishes to connect to a PC, converting this AV output to USB signals via a converter like the one described below enables input.

Industrial endoscopes are showcased on the Shodensha product website.

What cameras are necessary for a borescope?

Attaching a camera to a borescope results in diminished brightness. Consequently, cameras with high sensitivity or intense illumination are requisite. While our BA200HD model offers both affordability and high sensitivity, certain conditions of the object or the type of borescope may still result in insufficient brightness even with this model. While using intense illumination is an option, it can be costly.

Recommended feature: “Auto Exposure Master”

Here, we introduce our sophisticated high-definition camera. It combines advanced functionality with high sensitivity, rendering it highly effective in dim conditions, especially when coupled with the “Auto Exposure Master” feature. One drawback is the smaller camera sensor size, at 1/2.8 inches, resulting in a slightly narrower area captured in the imagery. However, this model performs well with borescopes with diameters below φ2.7.

What cameras are necessary for a borescope?

Attaching a camera to a borescope results in diminished brightness. Consequently, cameras with high sensitivity or intense illumination are requisite. While our BA200HD model offers both affordability and high sensitivity, certain conditions of the object or the type of borescope may still result in insufficient brightness even with this model. While using intense illumination is an option, it can be costly.

Recommended feature: “Auto Exposure Master”

Here, we introduce our sophisticated high-definition camera. It combines advanced functionality with high sensitivity, rendering it highly effective in dim conditions, especially when coupled with the “Auto Exposure Master” feature. One drawback is the smaller camera sensor size, at 1/2.8 inches, resulting in a slightly narrower area captured in the imagery. However, this model performs well with borescopes with diameters below φ2.7.

The sensor size of the camera connected to the borescope affects the extent of blurring. Conversely, it approaches the image seen directly by the eye.

The focal length (f-value) of the adapter lens also varies.

Confirmation was conducted using a φ4mm 0° borescope.

■ When using an 18mm focal length adapter lens:

(1) With a camera featuring a 1/1.8-inch imaging sensor:

(2) With a camera featuring a 1/2.5-inch imaging sensor:

■ When using a 35mm focal length adapter lens:

(1) With a camera featuring a 1/1.8-inch imaging sensor:

(2) With a camera featuring a 1/2.5-inch imaging sensor:

The field of view when a camera is connected to a borescope and observed on a monitor changes depending on various factors.

This time, we compared the following three points.

　(1) Borescope diameter (φ4mm and φ2.7mm)
(2) Number of camera inches (1/2 inch and 1/3 inch)
(3) f number of connected lens (mm) (35mm and 27mm)

(1) Comparison of borescope diameter between φ4mm and φ2.7mm
(Fixed camera size to 1/3 inch and lens to 35mm)

■φ4mm		■φ2.7mm

As mentioned above, increasing the diameter of the borescope will increase the field of view on the monitor.

(2) Compare camera inches between 1/3 inch and 1/2 inch

(Borescope φ4mm, lens fixed at 35mm)

■1/3inch		■1/2inch

As mentioned above, reducing the camera sensor size will increase the field of view on the monitor.

(3) Comparison of connected lenses between 35mm and 27mm

(Borescope φ4mm, camera fixed at 1/3 inch)

■35mm		■27mm

As mentioned above, increasing the focal length of the connecting lens will widen the field of view on the monitor.

In addition, our connection lens BA-A1835 allows you to adjust the field of view, so you can further widen the field of view on your monitor.

■■Full-field observation (using 1/2 inch camera)		■During magnified observation (using 1/2 inch camera)

By reducing the camera’s sensor size, it can be expanded to almost cover the entire monitor.

(When using 1/3 inch camera and magnifying observation)

For product details of the camera adapter, please see the product page below.

Basically, it fixes the handy light part and camera part.

 The feasibility of observing the interior of a hole using surface-emitting coaxial illumination depends on the diameter of the hole; larger diameters facilitate more effective observation.

The subject is the hole in a cylindrical metal object.	I utilized surface-emitting coaxial illumination to observe the interior of the hole
	– The coaxial illumination allowed light to penetrate deep into the hole, enabling clear observation of any imperfections or scratches within its depths.
	Surface-emitting coaxial illumination

– Endoscopes and borescopes are also effective methods for observing the interiors of holes.

	– High-function industrial endoscope with a 3.5-inch monitor MIGS300-V551 – Cable lengths of 1 meter and 2 meters are available for selection.
	– Flexible, user-friendly cable with a diameter of 5.5mm. The tip features a slim 4.0mm diameter type. MIGS300-401 (available in 1m and 2m lengths).
	– Borescope BAL-0418L (0°) – Available in 0° (direct view), 30° (side view), 70° (side view), and 90° (side view) types. – The outer diameter of the tube is 4mm.
	– Ultra-slim industrial endoscope – Equipped with a 0.7mm ultra-slim probe, enabling the inspection of precision-engineered components.

For more details about the product, please feel free to contact our technical support. We also accept requests for testing.

– When using a side-viewing (90°) borescope, attention must be given to the focal length.

Utilizing a side-viewing configuration inevitably results in a shorter distance to the wall surfaces (indicated by the red arrow).

– Upon magnifying the tip of the side-viewing borescope, it appears as follows.

• Compared to the direct-viewing type, the side-viewing type has a shorter actual focal distance (indicated by the blue arrow) due to the distance represented by the red arrow.

• In practice, a 4mm diameter side-viewing borescope was employed to observe the sidewalls of holes with diameters of 4.5mm, 6mm, and 7mm.

Even when utilizing the focal adjustment feature of the side lens with a diameter of φ4.5mm, the focal point remains entirely unaligned.

■The focal point barely aligns on the side with a φ6.0mm aperture.

However, discrepancies in product manufacturing may result in misalignment.

■On the side with a φ7mm aperture…

There is ample room for adjustment in the lens’s focal adjustment capability. Even accounting for variations in product quality, the distance remains sufficiently usable.

Observation of the side with aperture diameters smaller than φ6mm is made feasible through the utilization of a macro lens attachment ring.

I observed the side with a φ4.5mm aperture diameter by inserting a 5mm macro lens attachment ring.

■Observation of the side with a φ4.5mm aperture diameter (with the addition of a 5mm macro lens attachment ring)

Even at φ4.5mm (with a distance to the wall of 0.25mm), the focal point aligns.

(The presence of a distance between the lens and the mirror within the borescope allows for focal alignment even at 0.25mm.)

■Observation of the side with a φ6mm aperture diameter (with the addition of a 5mm macro lens attachment ring)

There is still room for further adjustment.

When observing the side with a φ4.5mm aperture diameter using direct (0°) wide-angle viewing, the macro lens attachment ring is unnecessary. (Adjustment is possible within standard specifications.)

■Observation of the side with a φ4.5mm aperture diameter (wide-angle, direct viewing)

The appearance when observed with the standard type of direct viewing is as follows for reference.

Please refer to the following for detailed product information on the “φ4mm side-view borescope” and the “5mm macro lens attachment ring” being used this time.

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.