View Full Version : Schneider-Kreuznach Xenar 150mm F/4.5 Copal 1

13-Feb-2019, 21:42
I bought this lens the other day but didn't notice the aperture cover doesn't have f/stop numbers on it. Like it's blank. I took the aperture cover off hoping it was inverted for some reason but there wasn't any numbers on the reverse side either. Any clues from those in the know? I did try searching the forum but didn't find anything specific to this particular lens.



13-Feb-2019, 22:56
If you search this forum, you will find lots of information on this subject. Here is one link:


13-Feb-2019, 23:01
Looks like the lens cells were transplanted into that shutter...Mine is in a Linhof-selected Synchro-Compur.
I recommend that you send it to SK Grimes. It shouldn't cost too much for them to engrave it. They can do half-stop and third-stop scales, also.
Check their website for pricing info.

14-Feb-2019, 05:10


Pere Casals
14-Feb-2019, 07:37
but didn't notice the aperture cover doesn't have f/stop numbers on it.

No problem, just DIY calibrate the aperture scale.

You need a $15 lux meter.

Or download a lux meter app for your smartphone, in the front face there is a lux meter that is used for screen auto-bright, the app uses that sensor, not a good lux meter (very directional) but perfect for this job as we use relative values.

Take another lens with a valid aperture scale, focus a distant object, measure LUX in the back at all apertures.

Take your Xenar and in the same situation (focus infinite, same subject) stop down to have the LUX measured for each aperture in the other lens, make the marks for each aperture.

For convenience you can do that in a room with dim light, with camera pointing at sky, then you can even remove the bellows to make it easier if your lux meter cannot rotate.


This $16 one has a head that can swing, so it's easier to take a reading in the back.

This gadget would also be useful to check aperture scales of your other lenses and to make film/paper calibrations, etc.

A sekonik that says lux is also good for that. But metering with stops is not as precise.

14-Feb-2019, 11:27
Lots of solutions. Thanks very much.