Proper setup? Sinaron 80mm digital lens

[Richard Levy]

Having just purchased an 80mm Sinaron digital lens at auction I now find I cannot focus the lens when objects are more than just several feet away.

Sinar 4x5 P2.

My configuration:
The lens is in a db mount on a large recessed board and I use Sinar auto aperture (not electronic) shutters. I'm using the wide angle bellows. The front and back standards can meet.

I've tried changing to the small square lens board, not recessed, that mounts into, not onto, the front standard. (To eliminate the extra distance the larger board adds).

Can anyone suggest what I may be doing wrong or what I may need in my setup?

Thanks in advance, Richard Levy

[ic-racer]

The seller indicated it would focus at infinity? The chart on the Sinar site does not indicate that it will focus at infinity. http://www.sinar.ch/downloads/category/8-objektive#

[Richard Levy]

Thanks for you reply.

The seller made no claims whatsoever besides condition.

But if I read that chart correctly it claims 141' max distance and I cannot get past 3'-4' before the camera will no longer focus.

[Ari]

The chart is a bit confusing; to me it looks like 141cm (roughly 4 feet), not 141 feet.

[Richard Levy]

You're right, very confusing. The label suggests "feet" are in the data somewhere. For what purpose is a lens that can only focus objects 15 to 55 inches away? Something's wrong.

[engl]

The lens can be focused at any distance, provided the camera is capable of holding the lens at the required distance.

The 37-141cm application range only indicates the distances for which the lens is optimized. The 80mm Sinaron is optimized for close focus, with reproduction ratios from 1:2 to 1:15. You can use it focused at infinity, just like you can with any macro lens, but performance won't be as good as a lens optimized for general photography. The more you stop down, the less it will matter though.

[Sdrubansky]

You should first try with the lens only 80mm from the groundglass/focus screen.

(Even if it's a close up lens you should be able to focus@∞
Which brings me to ask: what lenses that can't be focused at infinity?)

[Richard Levy]

Thanks for the info guys, I am glad to hear I can make this work. I can tell you that in the optimized range and shooting at f/8 the resolution, contrast and color are all stunning which is saying something because I am accustomed to working with Sinaron film lenses captured on a Phase One H25 back.

Now, where do I get the proper spacer that the DB mount uses to adjust the distance the rear element sits in front of the sensor (film plane) when focused at distances beyond about 14" (my current max)? The current spacer is about 1" wide.

Any sources/leads much appreciated.

Thanks, Richard

[Sdrubansky]

Can't help you with DB mount stuff, since I've no experience with it.
May I ask what camera you are using?

[Richard Levy]

I use Sinar 4x5 cameras. An X and a P2. I also have an 8x10 P but haven't used it in years as my work, commercial tabletop, is better suited to digital. Turnaround, client demands, image approval, etc.