Focusing problems with Iskra

[Diomedes]

I've found that my Iskra is focusing about 10cm behind the focusing point (at 1m). A vertical and horizontal alignment is accurate, I've checked that. So the problem is distance between the film and the lens. What is the best way to collimate it. I assume that I must push the lens slightly forward in my case.

Regards,
Vjeko

[Diomedes]

Daniel,

Thank you very much. I've found your instructions very useful. I've checked the rangefinder patch and found that lower right corner is the most useful at close range, just as you sad. I will test that with film very soon. Must I use that part of the rangefinder patch every time, even at infinity setting?

Regards,
Vjeko