dennis Lee
15-Oct-2000, 21:55
Hello all, I'm having a hard time getting a sharp image at infinity and close to infinity. I'm using a Century Graphic with Schneider 105/4.5 Xenar and an RH8 back. The back is in good shape and I keep the film tight while loading. Image softness is minor but 'soft' none the less. For a 6x9 image it's simply not useable.
The softness is even across the board (frame) on all frames. The GG matte is facing forward (towards the lens).
With a cheap caliper I checked the difference between GG mounting (front of glass) and film plane mounting. They are very close if not right on. Though the caliper is very cheap.
I spent a couple hours the other day setting the infinity marks so the GG was sharp across the board. It's possible the tree line I used was only a quarter mile away instead of half, but the images I shot later that day were at about the same distance if not a little closer. They are all soft.
My exposure was 1/60 - f16/f22 and I did not use a cable release. I wish I had but I didn't. I'm new to large format but I've been shooting for a long time, including 14 years at dailies, and this softness just doesn't look like camera shake to me. I'm going to do the old 'down the fence' focus test and see what that tells me.
NOTE A: I did shoot a close-up shot a couple weeks ago(camera on a tripod, inside the car, shooting a plastic whale on the dash in a rain storm, no cable release, f16 - 1/8), it's not razor, but it's sharper than my treeline.
Here are the questions: Could this lens be falling apart, some kind of image dispersion at small aperatures? Note A makes me think not.
If I were close to infinity but maybe not exactly on, wouldn't depth of field carry it (especially at f16/22)?
Does 'depth of field' reciprocate to the rear of the lens, back to the film plane? ie: smaller aperature=less film plane distance preciseness?
Could not using the cable release give me a slight softness or rather a dullness around what should be sharp edges? An example would be that the edges of leaves and tree branches simply aren't nice and razor sharp.
Thank you, DL
The softness is even across the board (frame) on all frames. The GG matte is facing forward (towards the lens).
With a cheap caliper I checked the difference between GG mounting (front of glass) and film plane mounting. They are very close if not right on. Though the caliper is very cheap.
I spent a couple hours the other day setting the infinity marks so the GG was sharp across the board. It's possible the tree line I used was only a quarter mile away instead of half, but the images I shot later that day were at about the same distance if not a little closer. They are all soft.
My exposure was 1/60 - f16/f22 and I did not use a cable release. I wish I had but I didn't. I'm new to large format but I've been shooting for a long time, including 14 years at dailies, and this softness just doesn't look like camera shake to me. I'm going to do the old 'down the fence' focus test and see what that tells me.
NOTE A: I did shoot a close-up shot a couple weeks ago(camera on a tripod, inside the car, shooting a plastic whale on the dash in a rain storm, no cable release, f16 - 1/8), it's not razor, but it's sharper than my treeline.
Here are the questions: Could this lens be falling apart, some kind of image dispersion at small aperatures? Note A makes me think not.
If I were close to infinity but maybe not exactly on, wouldn't depth of field carry it (especially at f16/22)?
Does 'depth of field' reciprocate to the rear of the lens, back to the film plane? ie: smaller aperature=less film plane distance preciseness?
Could not using the cable release give me a slight softness or rather a dullness around what should be sharp edges? An example would be that the edges of leaves and tree branches simply aren't nice and razor sharp.
Thank you, DL