Building a AV-Xenotar 150mm 2.8 lens for 4x5

**johnjuang** · 26-Nov-2021, 07:29

Originally Posted by Xifoideus

I have made a cardboard aperture around f22 ish. I have tried that in various locations. By complairing the preview on the ground glass I was able to see the best location. Just behind the 4th lens is the optimal spot to place it. Now I know where I have to cut the lens.

hi, many thanks for the information.
how the test go forward ? is there any details about the aperture position?
I got one a few days ago, and like to place an aperture with m58 mounting thread into the lens. hope you can clarify the optimal way to make it clear. thank you very much.

**Xifoideus** · 4-Dec-2021, 01:46

You should have the aperture as close as possible behind the 4th glass element.
It's not the most dificult to adapt. But it does not cover 4x5 and is not anything like the Xenotar. But a nice lens anyway.

**johnjuang** · 4-Dec-2021, 17:19

thank you for your answer. currently, I can't remove the rear element because of the fix ring was stuck very tight. I think it's a good way if I can get some information about the distance from the 4th element to the end edge of the lens body. is it possible ?

**johnjuang** · 14-Jan-2022, 17:46

because of the rear element cannot be removed (I think it's stuck tightly), I cut 38mm length off from the rear edge and that's the exact position just behind the 4th element. every thing is done for the modification and the result is great, it is really fantastic lens even without an aperture. I am very happy to finish the job and thank you very much for your information.