Two problems with new Ansco 5x7

[djdister]

So I tried the wall trick. The lens as a whole focused at infinity measured 5 3/8" from the wall.

Front group only - 11 1/2" to center
Rear group only - 5" to center

This was holding the groups with larger side toward the window. Is this correct?

By larger side you mean you were pointing the lens towards the window as if taking a picture of the window, then yes, that was correct. I'd say the results of this test show that the rear lens group is not the right match for a 180mm lens, and is a mismatched set of elements.
Keep the camera, get another lens.

[Joe Smigiel]

I'd agree. It would seem the rear group is not in the expected range.

[Jim Jones]

A diagram of the Sironar-N http://www.prograf.ru/rodenstock/lar...#Apo-Sironar-N suggests that it is fairly symmetrical. Thus, both the front and rear group should have somewhat similar focal lengths as Joe Smigiel says. The rear cell may well be missing one of its elements, or may be the wrong cell. Oops, two others replied while I was seeking information. I agree with them.

[brian steinberger]

Thanks guys for all your help! I will return the lens. In the meantime I will look for another lens. I may go with a 210mm to give me even more room for movements.

[Liquid Artist]

Has anyone mentioned getting a Recessed Lens board. It may correct problem 1 anyways.

[graywolf]

Actually, from the description in the original post, I thought he had a 180mm telephoto lens for a 6x9 camera; but his photos show a Sironar. Any chance it has a telephoto rear element on it?