LF technique question

k_jupiter · Jun 4, 2008

For my first shooting outing with my Deardorff 8x10, I went to a fairly known place to me and shot a couple of images on 8x10, a couple on 5x7.
5x7s look nice. Used the Arista Ultra 100 I did them in WD2D+. I then did one of the 8x10s in PyroCat HD rotary in a Jobo drum on a Unicolor motor, swapping ends every minute. To be honest, it looks just like the 5x7 in tone, scale, exposure, etc.

But... There is a line going down the end of the film, about 1/4 inch to 3/8 inch, straight but not parallel to the edge of the film. There is an image on both sides, but the image on the end side is about 2 stops less than the the main negative. I don't think it's development. It's too straight, and by rotating the drum end to end every minute, there would be no way to make it that consitantly under-developed.

So... COuld it be that I used too much movement in my 8x10 while shooting? Could I have caused an internal shadow in the Deardorff that I didn't pick up on the GG? My previous experience with LF has been primarily 4x5 or 3x4 based Speed Graphics. You know how much movement you get on those.

So anyone else found shadows in their LF field cameras?

tim in san jose

BradS · Jun 4, 2008

just guessing but...bellows sag? well...maybe? I dunno.

keithwms · Jun 4, 2008

Film holder leaks? If you put your neg back into the film holder in the orientation it was shot, do you see any correlation with the seals?

k_jupiter · Jun 4, 2008

BradS said:
just guessing but...bellows sag? well...maybe? I dunno.

Horizontal shot, shadow runs vertical in this position. I believe bellows, I just have not experienced bellows getting in the way of the light path from movements.

keithwms said:
Film holder leaks? If you put your neg back into the film holder in the orientation it was shot, do you see any correlation with the seals?

Light leaks would cause over exposure. This is apparently underexposure on one edge.

tim

TheFlyingCamera · Jun 4, 2008

Sounds a lot like bellows sag. This is rarely a problem on 4x5 or even 5x7, but it becomes much more common on 8x10 and larger, where the bellows are huge, and exponentially heavier, making them more likely to droop mid-bellows.

df cardwell · Jun 4, 2008

A Vertical line, but a Horizontal picture ? How do a Deardorff bellows sag horizontally ?

Can you post a snap of how the camera was set up when you made the picture ?

It is always a good idea to set up the shot, and peak through the cut out corners of the ground glass to look at the open diaphragm of the lens.

k_jupiter · Jun 4, 2008

TheFlyingCamera said:
Sounds a lot like bellows sag. This is rarely a problem on 4x5 or even 5x7, but it becomes much more common on 8x10 and larger, where the bellows are huge, and exponentially heavier, making them more likely to droop mid-bellows.

Scott, Why would the shadow be down the left side, not across the top if it was droop?

tim

TheFlyingCamera · Jun 4, 2008

You're right, it wouldn't. How much movement did you have applied? Could it be you were at the edge of the image circle, or the bellows vignetted due to horizontal movement?

removed account4 · Jun 4, 2008

hey tim

make a paper negatives when you test
your camera, it is much cheaper than film ( and easier too! )

could the line be something dangling inside the camera ?
you mention it is not parallel to the edge of the film,
does it go down the entire length of the film?

john

Deckled Edge · Jun 4, 2008

One of my 'dorffs has the orig. leather bellows, and they do droop. When it happens there is complete mechanical vignetting, not a 2 stop loss of exposure.
Was there pre-exposure of most of the film before the final exposure? A darkroom light leak, a holder malfunction, or user error? A bad sheet of film (I, too, use Efke, though I'm sure Arista has less problems here).
What lens and what movements?

Alex Hawley · Jun 4, 2008

Sounds like bellows interference to me, interfering on the side, not drooping from the top. Never have seen it on my 8x10 Dorff but its happened on the 7x17. I had to ask someone else the same question before I realized what it was.

k_jupiter · Jun 4, 2008

Deckled Edge said:
One of my 'dorffs has the orig. leather bellows, and they do droop. When it happens there is complete mechanical vignetting, not a 2 stop loss of exposure.
Was there pre-exposure of most of the film before the final exposure? A darkroom light leak, a holder malfunction, or user error? A bad sheet of film (I, too, use Efke, though I'm sure Arista has less problems here).
What lens and what movements?

300mm Kodak Comercial Ektar. Lots of movements (how was I suppose to know *L* ?

I would thinkedge falloff would be in a circular pattern. Perhaps not though at that image circle. I am thinking it's bellows interference from too much movement.

tim

df cardwell · Jun 4, 2008

post a picture of how the camera was set up

SAShruby · Jun 4, 2008

A spider net inside the bellows close to lensboard? I had that before...

Alex Hawley · Jun 4, 2008

k_jupiter said:
300mm Kodak Commercial Ektar. Lots of movements /QUOTE]

Tim, I use a 300 Commercial Ektar most of the time on the 810 Dorff. I've never had a problem with lens coverage except in very extreme cases of front tilt. I'm still betting on side bellows interference. The other possibility is a thin place on a bellows pleat. Have you checked the bellows for a light leak?

Don12x20 · Jun 9, 2008

Test for bellows sag is similar to compendium check....

With lens open, and set at the desired aperature, look through the lens and see if you can see all four corners of the ground glass. You'll see the bellows in the path if it is there. Note that this test is easier than looking through the corners of the ground glass to see if you can see the round lens aperature - both from the physical angles (especially top two gg corners) as well as the GG seems brighter at even low light conditions than the lens opening seen from the gg...

And for your deardorf with flatbed, get some scrap pieces of mounting board, and some mounting tape. Make a bottom piece that fits on the flat board of your rail section. Put some 1/4 inch strips across this piece, separated by gaps. Now take two sections of mounting board - the width of the belows and long enough to form an upside-down V between the bellows bottom and the horizontal rail platform. Use mounting tape to tape the two as a flexible V. Now tape these to the bottom mounting board along one end only -- the other goes into one of the slots you've created.

This allows it to be collapsed when traveling, and to open up and adjust to the belows height needed (one presumes you'll have to work out the lengths but this should describe the concept.
I made one of these for sagging bellows on my Canham 12x20. Works great. Cheap. With thick mount board it lasts forever. The center discard portions of mounted work are free...if you don't do your own mounting, ask a local framing shop. IF it gets wet or dirty, make another.

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