Wierd Lens Q.

[iMacfan]

Hi,

A recent GAS attack resulted in the arrival this morning of a Canon FTb (has mirror lock-up for macro, and was only about $20) - however the lens that came with it has me puzzled. It's a 'Coligon' Japanese 135/3.5, and is not coupled in any way to the body, and reminds me of my Jupiter-11. What is so very odd (apart from the focus marks being way off - like the other side of the lens!) is that there are two apeture rings. Why? They both appear to control the same iris. Does anyone know?

Thanks,

David

 

[Sonnar Brian]

This is a "Pre-Set" lens. One ring should have click stops and the second ring should move freely. Set the Desired F-Stop using the ring with fixed stops. While focussing, leave the 2nd ring in the fully-opened position. Before shooting, move it until it hits the stop "Pre-Set" with the first ring. Not the most convenient, but better than full manual.

$20 for a Canon Ftb. And who says Digital Cameras are all-bad...

 

[pshinkaw]

The Coligon is probably a T-mount lens. If it uses a T or T2 adapter, you can move the focusing marks wherever you want them to be. Just set the camer on its back with the lens facing up. Use a small jeweler's screw driver to loosen the three set-screws on the T-mount adapter and rotate the lens to the desired position. re-tighten and you are all set.

-Paul

 

[iMacfan]

This is a "Pre-Set" lens. One ring should have click stops and the second ring should move freely. Set the Desired F-Stop using the ring with fixed stops. While focussing, leave the 2nd ring in the fully-opened position. Before shooting, move it until it hits the stop "Pre-Set" with the first ring. Not the most convenient, but better than full manual.

$20 for a Canon Ftb. And who says Digital Cameras are all-bad...

Thanks, that appears to be the intention with this lens, but I think someone has been 'at' it. In addition to the DOF markings being 90 degrees askew from the correct focus point, the preset apature will let you stop down completely, set a click stop and open up to that point before you get any resistance. When I have a bit more time, I'll dismantle the lens, and at least I might learn something if nothing else...

David