VA-LADAP-LCM-4xF-150, 4x focal length extender

Focal Length Extenders

A focal length extender is an optical adapter ring between the (C-) mount of the camera and the C-mount lens. With this Adapter, you are able to increase the focal length of an industrial c-mount lens. As a result, with a 2x focal length extender you zoom a factor 2 and with a 4x focal length extender you zoom a factor 4. It’s used for microscopic views at short working distances or looking at small objects at larger working distances.

Practical examples

If you combine a 50mm lens with a 2x focal length extender, the new focal length will be 100mm. If you combine a 50mm lens with a 4x focal length extender, the new focal length will be 200mm.

Application examples

Applications where you are looking at microscopic an object with a field of view of 1x1mm and a working distance of 100mm or the inspection of objects with a distance of 3 meters while the field of view is just 100x75mm.

Important remarks

There are a few important remarks you have to keep in mind when using a focal length extender:
-    The adapter only works with c-mount lenses, not with M12 lenses
-    The maximum supported sensor size is 2/3 inch.
-    You cannot combine multiple focal length extenders.
-    Some lenses will lose the ability to focus until infinity. The minimum working distance will not change.
-    You will lose light intensity. When using a 2x focal length extender, you lose 2 aperture stops of light. A F1.4 lens becomes a F2.8 lens. With a 4x focal length extender, you lose 4 stops. A F1.4 lens becomes a F5.6 lens.

Below you can find a comparison with and without the 4x focal length extender

Camera: MER2-503-36U3C
Lens: VA-LCM-5MP-50MM-F1.4-015
Working Distance (WD): 700 mm
Field of View (without extender): HFOV 120 mm, VFOV 100 mm

4x Extender (VA-LADAP-LCM-4xF-150): 
Quadruples 50 mm lens to 200 mm; causes 4 stops light loss (example: F1.4 → F5.6) requiring brighter illumination.