Why am I getting unexposed area on 4x5 sheet film?

[Hao]

First and foremost, greetings to all the friends here in the LFP forum!

Recently I've gotten negs with unexposed area at the top side of the image when shooting vertically.
The camera is Wista Rittreck View with 4x5 back. I also use the original extension hood to block out the unwanted light.
I employ some movements as well, front tilt and back tilt/swing.

I've been going back to do some test shots, trying to figure out what went wrong in the workflow.
The result seems to be consistent. The negs from the same location/setup would show the same amount of unexposed area at the top.
I paid attention when viewing the ground glass if the bottom is blocked (the top of the neg), however cannot be 100% certain when I reviewed the negatives...

I remember that "what you see is what you'll get" rule in large format view camera. If that's the case, could people tell me what else I might have missed in the process?

I will post some example below for the reference.

Thank you very much!

[Randy]

Has me baffled.
Do you pull the dark all the way out?...no, that would be showing at the bottom of the image.
Not having the film holder inserted all the way in?
Lens rise / fall beyond lens coverage?
The only other I can think of is the lens hood.

[Michael Clark]

Could be the lens shade blocking the view when using front movements, like tilt, rise, fall etc.

[Doremus Scudder]

It's probably bellows or your lens hood blocking a bit of the image. Unfortunately, what you see wide open focusing is often NOT what you get. Whatever is blocking the image is likely not really noticeable when viewing wide open for focusing, but comes "into focus" when you stop down. Set up your camera for a similar shot and then stop down to your taking aperture and check again. I'll bet you'll find the culprit in no time.

Best,

Doremus

[Vaughn]

I vote for sagging bellows. If you GG had cut corners, you should be able to see whatever is blocking the light. If you do not have cut corners: After setting up the camera and before you put the film holder in (also no dark cloth), try looking in from the lens and making sure you can see all of the GG.

The image is pretty dark around the edges -- easy to miss seeing something like this.

[richardman]

Sagging bellow would make the BOTTOM area unexposed, not top.

[LabRat]

So if the top is being cut-off, that means something is shading at the bottom of the camera... (Or a hood, as suggested...)

How much front rise are you using??? Any excessive movements will cause the bellows to flex, and sometimes end up in the optical path...

Also, the inner lining of the bellows might be loose inside, and when using movements, might pop a little away, getting into the optical path...

Take the rear focusing panel off the rear, and extend the bellows to your shooting extension... Have a lens on the front... Then look through the camera (without GG), put your eye or ruler at the bottom corner of the rear cut-out and line it up with the edge of the lens, and the center (where the stopped-down iris would be) and check that there is nothing that might be sticking out that would cross that line... Repeat while using you movements...

Also, if you are using a reduction back, some of them are a little thick, and one of the edges might be getting into the optical path on extreme movements... Check that, too...

Steve K

[ic-racer]

I also use the original extension hood to block out the unwanted light.

This has all the components of a frequent beginner's mistake.
You need to stop down your lens to check the compendium shade. A lens 'Sees Around' any object smaller than the aperture diameter. Wide apertures don't show the shade (or finger held in front of the lens etc.) Aperture has no effect on the angle of view on the film, so don't think you want a wide aperture to see the shade at the bottom edge of the frame.

[Paul Metcalf]

Sagging bellow would make the BOTTOM area unexposed, not top.

The bottom is the top (of image) with a view camera

[Jac@stafford.net]

I have done accidentally that exactly as ic-racer described with a messed up (improvised) compendium.

The bottom is the top (of image) with a view camera

To clarify: the image is inverted in the lens. An object intruding in front of the lens is a different matter, but I'm sure you know that.