Lens Coverage?

[David Gardner]

First, thanks to those who have answered my previous questions. This is a very f riendly and helpful board.

I have had a (several?) recurring problem with my setup, a Calumet CC400 with a Schneider-Kreuznach Angulon 90mm. I don't seem to be able to use much if any cam era movements without losing focus. Last week I took a shot with full rise, and a little added rise via a base tilt-type maneuver. The upper corners were vignet ted, and a circular, arc-shaped band extending about an inch below that was very out of focus.

A friend told me that the vignetting was likely caused by the bellows, but I hav e the short bellows wide angle version of the camera. And that still doesn't exp lain why large portions of my shots go completely out of focus whenever I try to add tilt or swing (and I have attemtped to refocus, BTW, to no avail). Am I usi ng the movements incorrectly?

Any help is appreciated, and thanks in advance.

David

[M.]

No, it's the lens. Even stopped 'way down, an Angulon will barely cover 4x5 with only a little room for movements (less than 1/2" of rise). As to the out of focus problem; I'll bet that the central portion of the image can be refocused sharply, only the periphery is smudged. I'm afraid you need a SUPER-Angulon. Either that, or call it ART and sign your prints "Atgent."

[John Hicks]

The Angulon just covers 4x5 and has hardly any coverage for movements. For more coverage you'll need a Super-Angulon, Grandagon-N, Nikkor-w or something similar .

The soft band you see is a hallmark of older lenses; there's a circle of good definition that's somewhat smaller than the total coverage, while with modern le nses the circle of good definition is pretty much right out to the limit of cove rage.

I think it's probably time to go shopping for a new lens. The 90 f8 Nikkor has about the same coverage as the bigger and more expensive f5.6 Super-Angulon and f4.5 Grandagon-N but otoh the faster lenses can be much easier to focus.

[william blake]

I have the 90mm f6.8 Linhof and I love it despite it's limitations -- with bw film at f22 it is equal to or better than my 90 f8 Caltar. I have a couple shots ruined where I tried to shift too much -- still gets me once in a while -- for a press camera like mine, where fewer movements are availible the Angulon is fine. And so small! I use the Angulon on my press camera and the Caltar on my view -- I don't have an extra board to put the Caltar on my press camera.