Videoscopes: Discovering new horizons!

No secret that Medit Inc offers a wide range of inspection devices: borescopes, fiberscopes and videoscopes. But what many people don’t know is that these medical and industrial tools are also used to make movies and television programs. Here we’d like to take a look at a bright example of videoscopic film-making.

Today, these interesting devices are widely used for tasks ranging from emergency rescue to aircraft engine and nuclear power plant maintenance. Wonderful that as technology has advanced, the image quality and mobility of videoscope systems have improved, thousands of unexpected new uses have been found for these versatile tools. Two cinematographers, Jeff Morales and Alastair MacEwen, made an interesting film for National Geographic Television & Film’s popular Explorer series and television specials. Their one-hour program, titled ‘Insect Wars,’ gives viewers an inside look at a world they would otherwise never see.

Murder, torture and imprisonment may be the standard tools of repressive regimes – but humans do not have a monopoly on such tactics. But I'm sure we shouldn't act like insects - we are human beings!

Videoscopes played a key role in capturing some of ‘Insect Wars’ most dramatic footage. When you watch Matabele warrior ants mount an attack in South Africa, or slave-taking Polyergus ants conduct a raid in Arizona, you feel the presence of giant insect empires engaged in war.

Videoscopes also take us inside a hive of honeybees to show the unique defense mechanism of bees to protect their nest – with heat generated by vibrating their bodies.

No doubt, the future will discover new fascinating examples of videoscope application. Maybe you will pioneer these new areas of application. And our company will do help you! 

Borescope Illumination

If you use a borescope it is necessary to illuminate the object you are observing. There are two basic types of borescope illumination: hot light and cold light. Hot light means the borescope contains a bulb at the tip. This is no longer common but some scopes still use this type of illumination. It has the downside of heating the object as well as the potential to break the bulb. Cold light means that there is an external light source and the illumination is transmitted through the scope using optical fiber. 
Light sources vary from portable flash light types, which attach directly to the borescope, to metal halide arc lamps, or even 300 watt Xenon lamps. For the line powered light sources it is necessary to use a fiber optic light guide (or a liquid light guide) to connect the light source to the borescope. 
The amount of light you need depends on the size of the cavity that you need to illuminate, the amount of Illumination fiber in the borescope and the sensitivity of the detector, be it a camera or your eye. For illuminating most machined metal parts, metal tubes, rifle barrels, etc. a simple hand held portable light source can be used very effectively. When viewing larger cavities such as engine cylinder, large casting, inside of walls, fuel tank, oxygen tanks, etc, then you will need a higher-powered light source.

More details on borescope light sources can be found here

How Do Borescopes Work?

There are three major types of borescopes: Rigid, Flexible and semi-rigid. All borescopes have an objective lens at the tip, much like a camera lens, to form an image of the object to be viewed. The objective is followed by an optical relay, to transmit the image down the tube. The eyepiece then magnifies the image to be viewed by the eye. The major difference in the three types of borescopes in the optical relay.

Rigid borescopes

Rigid borescopes use lenses to relay the image down the tube. These can either be a series of achromatic doublets, Hopkins relay lenses (often referred to as rod lenses or Hopkins rod lenses), or a GRIN relay lens. These rigid borescopes give the best image quality of the three types. The resolution is typically diffraction limited at about f/5, meaning that the relay lenses have a resolution of resolve 5 microns. This means that a typical 4 mm diameter rigid borescope having a roughly 2 mm diameter optical channel, can resolve 400 lines(200 line pairs), or approximately 130,000 pixels. A typical 8 mm diameter rigid scope may have a 4 mm diameter image and therefore 800 lines (400 line pairs) or about 500,000 pixels. Rigid scopes have the best resolution by far. Prices range from $500 to $3000 depending on the features. The rule is always use a rigid if you can. Only use a flexible if you have to.

Rigid borescopes can typically be purchased with various directions of view for looking at different things. Zero degree (Straight ahead) and 90 degree are the most common. Ninety degree scopes are often used to inspect tubing, rifling, weld joints, cross, holes cylinder walls, turbine blades, etc. Seventy degree and 110 degree scopes are also commonly used for viewing valves in engines. Different fields of view are also available.

Flexible Borescopes

Flexible borescopes use coherent fiber optic imaging bundles to relay the image from the objective to the eyepiece. These bundles allow the scope to be flexible but at a high cost in resolution. Typically these bundles resolve 10,000 to 30,000 pixels … roughly a factor of 10 less than a rigid borescope. There are two types of fiber optic image relays: fused and leached. Fused fiber bundles tend to have smaller diameter fibers, giving higher resolution. However, they have cross talk between the fibers reducing contrast. Blacks aren't as black and whites aren't as white. They are also less flexible than leached bundles and are therefore more prone to break. Leached bundles have typically 10,000 to 20,000 pixels. The fibers are separated so that there is no cross talk, giving much higher contrast. It is hard to emphasize the importance of contrast in writing, but when you see the image, it is dramatic. High contrast is important, often more important than the number of fibers. Having more fiber doesn't do you a lot of good if the image is low contrast. You won't get the resolution you want anyway. Quality flexible borescopes are also much more expensive than rigid borescopes. Prices range from $1500 for non articulating to $15,000 for high-end articulating models. Once again, use a rigid borescope if you can, use a flexible scope if you have to.

Flexible borescopes can be either articulating, or non articulating. A 4 way means that the tip of the scope can be articulated up/down and left/right. A two-way scope would only be left/right. If you need to snake through a bent tube, a non-articulating borescope may be just fine, but if you want to go through a hole and look around inside a cavity, then you probably need articulation.

If you're looking to buy a rigid borescope find them here
If you're looking to buy flexible borescopes see them here

Flexible or Rigid?

Rigid borescopes give higher quality images, are easier to use and are less expensive than flexible scopes of similar quality. Choose a rigid borescope unless the rigidity is a problem, and always choose the largest diameter scope possible. A flexible fiberscope lets you see inside spaces that a rigid borescope can't penetrate. Viewing inside dark cavities is easily accomplished through a variety of optional light sources. For field inspections, high-power handheld rechargeable light sources work best. However, an external AC powered light source and light guide will provide the most amount of light.
You can find a good selection of rigid borescopes and fiberscopes at the Fiberscope.net specialized online store.

Why Do I Need a Borescope?

There are many applications where borescopes are useful and even critical. Borescopes are used routinely by quality control departments to inspect machined parts for automotive and aviation components. Key components such as fuel nozzles, manifolds, hydraulic components and systems, welded tubing, engine cylinders, valve seats are all inspected using borescopes. The borescope allows the inspector to see defects inside the part that would otherwise go undetected, causing a potential failure down the road. Without borescopes, quality control people often resort to destructive testing which is both costly and time consuming. Borescopes can pay for themselves quickly by finding problems BEFORE the parts get to the customer, by eliminating the need for destructive testing, and by improving overall quality.

Gunsmiths and precision shooters also use borescopes to inspect rifle bores. for defects, wear, fouling and erosion.

Aviation mechanics use borescopes to inspect turbine engines, to inspect compressors and fuel nozzles to inspect combustion chambers and many structural inspections as well.

Auto and diesel engine mechanics use borescope to inspect cylinders, piston crowns, valves and valve seats. This often prevents costly time consuming tear down.

Building inspectors use borescope to view behind walls for structural issues, mold, termite damage, water damage, etc.

Find a convenient borescope for your industry here

Video Borescope Is Easier To Use

I found an article describing the convenience of videoscope using for engine maintenance. It's just an example of borescope application, and we offer far better products than described here. If you are looking for a good instrument for engine servicing, you are welcome here.

by Dick Bernier

JT8D engines are borescoped on an "as needed" basis, such as when significant fan-blade FOD is found and maintainers suspect compressor damage farther downstream. Another reason to look at a compressor is when an engine experiences a stall, surge or chug. The only way to know if the problem was caused by compressor-blade damage is to use a borescope. Older borescope equipment found at each squadron's Raytheon on-site storeroom (OSS) has a large eyepiece and is difficult to use. The Navy now has a six-millimeter videoprobe borescope available for C-9B and DC-9 squadrons. This new gear uses a hand-held videoscreeen in place of an eyepiece, has the capability to measure damage found by the probe, and saves the image to floppy disk. You can view these photos on a computer screen and transmit them by e-mail. The small diameter of the insertion tube, 6 mm vs. 8 mm on the old type borescope, allows easier access to the 13th stage blades. Access is gained by going through the igniter-plug hole near the compressor-discharge area.

What is a videoscope?

A flexible Videoscope or Video Borescope is an advanced type of borescope that houses a very small Borescopes with CCD chip embedded into the tip of the scope. The video image is relayed from the distal tip and focusable lens assembly back to the display via internal wiring. This is unlike a traditional Borescope and Fiberscope. Borescopes use hard optical relay components to transfer the image from the tip to an eyepiece and Fiberscopes use coherent image fiberoptics to relay the image to one's eye through an eyepiece. The image quality of a videoscope is superior to a fiberscope and could be compared to that of a high-end Video Camcorder.
Videoscopes are normally 10 mm or less in diameter and come in lengths up to 50 ft. Several integral features include the insertion probe section, the articulated tip, articulation controls (up down left right) on the control handle, lighting bundle, high intensity external light source and cable interface with outputs to the display (LCD or CRT) and external media recording device such as computer hard disk or compact flash card. The system normally will record either live video or still photos.
As either an AC or DC portable visual inspection system, the components are designed to be compact and be hand carried without shipping cases on wheels or large boxes.
You can find additional information and/or buy these devices here

Basics about borescopes

Borescope is a rigid (industrial endoscope) or flexible (fibrescope, flexible borescope) tube with an eyepiece on one end, an objective lens on the other linked together by a relay optical system in between. Borescopes are used for inspection work (borescope inspection) where the area to be inspected is inaccessible by other means. There is 2 main types of borescopes. Flexible borescopes also are called Fiberscopes - because their relay optical system that trasfer image consist of thousands of tiny fibers (fiber optic image bundle). Rigid borescopes (bore scope) are similar to a fiberscope, but have a higher quality image and are not flexible. Rigid borescopes are therefore better suited to certain tasks such as inspecting automotive cylinders, fuel injectors, hydraulic manifold bodies and gunsmithing. Rigid Borescope on sale or flexible fiberscope may be fitted with a magnifying device and a way to illuminate the work being inspected, usually illumination fibers contained in the insertion tube of the borescope. The eyepiece may be fitted with a coupler lens to allow the borescope to be used with imaging devices such as a video cameras for borescopes. Borescopes can be used for rifle inspection and precision shooting as well.

You can find additional information and/or buy these devices here: http://www.fiberscope.net/