Is this bellows flare?

[Scott Whitford]

Just finished making contact sheets of 16 4x5 negs I shot yesterday and was frustrated to find almost every sheet is fogged.

The fogging is mostly in the center of the frame...sometimes even appearing as a 2-3 inch diameter circle in the center of the sheet.

Details: I was shooting still-lifes with a Linhof TechV and 210mm Sironar lens. I was stopping down to F/32 or even f/45 for dof, and the exposures were up to 60 seconds.

I noticed that the shots taken at f/45 have more fogging than those at f/32, which have more fogging than those at f/22. Maybe this isn't surprising due the correnspondingly longer exposures (?)

The bellows were cranked out to 12 inches or so for these shots, and I know that the 210 Sironar would probably just about cover 8x10 under these conditions (especially when stopped down so far...). That's why I suspect bellows flare.

The lens was not shaded, but there was not much light falling directly on the front element (using light from a north-facing window).

The bellows have no pinholes the last time I checked (but I'm going to check again this afternoon to make sure).

My only confusion is that in other posts regarding bellows flare, it seems to mostly occur along the edge of the negative...mine's definitely concentrated in the center.

Any thoughts?

If this is typical of bellows flare, any tips for avoiding it in the future? (Never had this problem under identical circumstances with my Graphic View II....yeah, yeah, I know - I should have used the GVII...).

Scott

[Donald Qualls]

It sounds as if your fogging is proportional to exposure time (you said the smaller apertures had worse "spot" fog, I'm assuming reasonably constant light). That sounds more like a light leak, similar to the translucent bellows on most Aletta cameras as originally sold, than any kind of flare. Another potential source of a center-weighted light leak would be around the lens board or around the shutter within the board -- and depending on your exposures in this session, the same problem might not have been noticeable with other subjects (dark slide open time would determine the fog level with a light leak, but that's going to be a lot longer with, say, a 1 minute exposure than with a 1/25 second).

My limited experience with bellows flare is that it's pretty much overall, or may show slight shadowing along one or two edges of the negative on the side where the bright light would strike the bellows (shading by the folds). I would surely not expect anything vaguely like a large circle. However; if the general light level inside the camera is high enough, you might be picking up a reflection or scatter off the film, refelected back and partially focused by one of the glass-air surfaces in the lens to cause the circle, in which case it would likely be dependent on exact focus position as well as excess coverage or other source of stray light.