JAI TM-1327GE Series, User Manual

Page: 34 / 52

TM/ RM-1327GE Series
34 Hardware Installation
7.2.4 Attaching the Camera Lens
The TM-1327GE camera accepts 2/3” or larger format size C-mount lenses. To attach the C-mount
lens1
2
to the camera, carefully engage the threads and rotate the lens clockwise until it firmly seats
on the mounting ring. Do not force the lens if it does not seat properly.
Note: Some lenses with extremely long flangebacks may exceed the mounting depth of the camera.
7.2.5 Adjustable Back-Focus
Before cameras are shipped, back focus is carefully set using a collimator, oscilloscope and other
specialized equipment. While the factory-set focus serves well in most cases, an adjustable back
focus makes it possible to improve image sharpness when using lower-cost zoom lenses, custom
optics, or in unusual parameters.
There should be an obvious need to refocus the lens before attempting to change the back focus.
This is a very exacting task. Some cameras have been returned to the factory to reset the back
focus after failed attempts to change the focus by customers. It might be wise to label cameras
whose back focus was adjusted
1. The camera must be connected to a monitor before attempting to adjust the back focus.
2. To back focus the camera, first attach a C-mount lens in the mount. Be certain that the lens is
properly seated.
3. Next set the lens focus to infinity (if the lens is a manual iris, set the iris to a high f number
while still retaining a well illuminated image).
4. Loosen the three miniature hex set-screws (use a 0.9 mm hex wrench) that lock the focus ring
in place (two screws for a CS-mount). Slowly turn the lens and focus ring assembly back and
forth until you obtain the best image of the desired object. This sets the back focus. Once the
best image is obtained, tighten the focus ring set-screws until they are snug. Do not over-
tighten the screws.
Note: Mini-bayonet cameras adapted to C-mount do not have the back focus feature.
Figure 29. Back-Focus Set-Screw Locations
2
C-mount to F-mount and C-mount to K-mount adapters are available for larger format lenses (35mm). Check with local
photography dealers for these lens adapters.