ITI's Camera Dedicated Borescopes

Direct Video Imaging

Camera Dedicated Borescopes are borescopes that focus their optical images directly
onto video cameras without use of auxiliary eyepieces, adapters, or magnifiers.

When borescopes were first attached to video cameras, the very small borescope images
(2mm to 4mm diameter) had to be magnified several fold to fill the large 16mm diameter
format of 1" vidcon cameras. With these high 4X to 8X magnification factors, came two
major problems:

• High magnifications resulted in very dark video images.
  Magnification is inversely proportional to image brightness.
• Existing image distortions in borescopes were also magnified.
  Magnification is directly proportional to aberrations

Magnification was accomplished by attaching a video adapter containing magnification
lenses onto the eyepiece of borescopes. The addition of this extra mechanical / optical
component often further distorted performance due to misalignment, while the addition
of extra lenses further reduced image brightness. (See Figure 1)

              

             Figure 1. Typical Borescope With Video Magnification Adapter

Beyond all of the optical and mechanical problems associated with coupling borescopes to
video cameras was the major physical problem of the size and weight of video cameras.
Cameras overwhelmed small diameter borescopes and made handling very difficult.

Beyond all of the optical and mechanical problems associated with coupling borescopes to
video cameras was the major physical problem of the size and weight of video cameras.
Cameras overwhelmed small diameter borescopes and made handling very difficult.

A major breakthrough came with the development and miniaturization of solid state video
cameras. First came the 2/3" camera (11mm diameter) quickly followed by the 1/2" camera
(8mm diameter). Today we now have 1/3" cameras (5.5mm diameter) and 1/4" cameras
(4mm diameter) with both 1/5" and 1/6" cameras in development stages. (See Figure 2)

              
                           Figure 2. Evolution of Camera Formats

Along with size reduction came tremendous improvements in resolution and low light level
sensitivity. Cameras became smaller, better and less expensive. Because the camera format
has been reduced to practically match the borescope image size, there was no further need
of adapters with magnification lenses. Borescopes could now deliver images directly to the
camera without increasing light losses or degradations due to eyepiece and adapter interfacing.
The time came to consider attaching cameras directly to borescopes.

Other recent advancements in electronics and digital information processing have helped
make video imaging the preferred method of borescope use. Images on a monitor can be
seen simultaneously by others, studied, enhanced, recorded, documented and even transmitted. 
The cost to do so became reasonable.

Digital camera development made it possible, customers requested it; now was the time for
Camera Dedicated Borescopes.

But first borescopes had to be redesigned to take full advantages of these new opportunities.
Since video cameras are not as forgiving as the human eye, borescope optical systems had to
be improved in several areas to meet critical camera performance requirements. The most
difficult requirement was greater uniformity from center of image to edge. Higher resolution
to edge, brighter illumination to edge, and most important, flatter fields center to edge.

The newest Camera Dedicated Borescopes by ITI were developed to meet these new standards
with better clarity, better resolution, faster systems and increased uniformity. Borescope images
have never been better. (See Figure 3)

                                

                                  Figure 3. Camera Dedicated Borescope

Fortunately, visual performance is also improved as a result of the new camera dedicated design.
A variety of eyepieces are available, all of which quick - connect to the borescope as readily as
a video camera. The visual inspector benefits from camera improved optics by "seeing" clearer,
brighter images with far less distortions than previously available.

Previously, borescopes were primarily visual instruments with camera adapters required for video
presentation. Now borescopes have become highly corrected camera lenses also optimized for
visual use through use of detachable eyepieces.

Direct Video Imaging is now a reality and the overall gain is total system performance improvements.  

Instrument Technology, Inc. (ITI) again leads the way with the introduction of industry's first Camera
Dedicated Borescopes.