Try this: Take the lens off the camera and point the camera so the GG is illuminated. Focus the loupe so the texture of the GG is sharply defined.Originally Posted by Axel
Try this: Take the lens off the camera and point the camera so the GG is illuminated. Focus the loupe so the texture of the GG is sharply defined.
One man's Mede is another man's Persian.
Axel, I seriously doubt that it's your eyes. If it was your eyes, you wouldn't see anything as being sharp. Do you know if your camera had shims between the GG-Fresnel set and the frame?
From what it sounds like, your GG-Fresnel combo is out of plane with the film. My Super Graphic's original GG-Fresnel had been replaced with just GG, and so I had to buy a replacement set, test it and shim it. Now it's a camera I won't give up. IIRC, before I shimmed it I had the same front-focus problem as you describe, but a bit worse. As has also been suggested, something may have hung up in the holder path. If your camera has a felt light trap, check to see that it's in its proper place.
"It's the way to educate your eyes. Stare. Pry, listen, eavesdrop. Die knowing something. You are not here long." - Walker Evans
The Sinar's back has milled bosses to position any thickness of ground glass in the proper position without shims or any fuss. The Sinar fresnel is external and only used for composition, not focusing.
I suspect that you gradually began to focus improperly over time as your eyes aged and changed. For me it all occurred in less than a year, and if you use longer lenses stopped down you might never notice that you've missed focus.
Try some reading glasses, try to focus on the ground glass without any loupe, then confirm that focusing with a loupe. What looks good and sharp at a distance should also agree with your loupe. If not then it is time for glasses.
For three different GG/frame combos? You can rule out the Fresnel, by the way, that is a instant removable behind-screen accessory on Sinars.
Hmmm, my experience with Fresnel lenses comes from Toyo and Graflex, where the Fresnel is between the GG and the lens. My other cameras don't have Fresnel lenses, just plain GG.
I really think something is funky with the equipment, especially if all of this happened after trying the DaYi holder. On my Graflex and Toyo holders, the backs have clips to seperate the GG and springs from the back, exposing the Graflok clips. So Axel tried three different backs, but I don't know if that is like the small section that pops off the back, or if it is the entire rear standard section that clamps on the rail, and the bellows attach to it. If the "backs" just clip on to the rear standard, then there could be something that is throwing off alignment.
"It's the way to educate your eyes. Stare. Pry, listen, eavesdrop. Die knowing something. You are not here long." - Walker Evans
Thank you all again !
(I seriously hope it is NOT my eyes)
The main Norma back... let me take a photo, it'll be easier.
The fresnel rests unattached on the bottom of the Norma frame (ie, the lens side) while the GG rests on the two clear patches (the "milled bosses" ; no shims indeed) and secured by the regular screws and tin bits.
This back is the one I've used since 1990 ; no reason it should suddenly "stop working" ; the other one is the same except it has no fresnel under the GG but the GG rests on the same places and is attached with the same system.
Both frames, fresnels and GGs are absolutely identical ; when I swap them to check for focus, the results are also absolutely identical.
@ von Hoegh
Try this: Take the lens off the camera and point the camera so the GG is illuminated. Focus the loupe so the texture of the GG is sharply defined.
Playing with the loupe, I don't see any difference : it's all sharp to me. But I don't see any "texture", or grain, only the concentric circles (for the one with "built-in" fresnel) or indeed the grain (for the other).
@ Brian C. Miller
As has also been suggested, something may have something may have hung up in the holder path. If your camera has a felt light trap, check to see that it's in its proper place.
I'd then to think the crux would be of that kind but the felt is fine, nothing anywhere, either in the Norma or on the chassis/Horseman/Calumet.
@ Otto
[...]and if you use longer lenses stopped down you might never notice that you've missed focus.
When I see the full-size 4x5" scans of the Perrault and Nouvel images, trust me... I'm on focus :) By that I mean "spot on on focus", not the focus I'd get only because I'm stopped at f16 or f22 : it's exactly where I meant to place it when doing each shot.
@ Sevo
For three different GG/frame combos? You can rule out the Fresnel, by the way, that is a instant removable behind-screen accessory on Sinars.
I have three backs but actually only use two (since this problem crept up) : one has the detachable front fresnel, the other has it under the ground glass. Practically speaking, if I focus with one then check with the other there is absolutely no difference in focus point.
Never mind now -
I'll see an optician tomorrow and see what, if anything, has to be seen after. And if it ain't my eyes, I guess my old Norma has done its time (I think it's a mid or late 50s model) and I'll either have to go get my P2 (for field work - argh) or buy a decent F2 with no ageing issues.
Will keep you posted - thanks for your help and suggestions.
ax.
Why not try the back from the P2 on the Norma and vice-versa? Seems impossible that the camera would be the problem.
Ah Yes on the oldest Normas the fresnel was between the ground glass and lens, they claimed the backs were calibrated for it.
On the contrary, I'd think that all those backs and all those lenses exhibiting the same problem would indicate that it has to be the camera.
I once had a 67mm polarizer that caused a focus shift (it was a Hoya) with all my lenses, I had cleverly adapted all my lenses to 67mm so I could use one set of filters, which meant...the same polarizer. Careful photographer that I am, I focused without the filter then applied the filter factor, and judged the polarizing effect before I put the filter on the lens. Could be something as simple as that.
JD
Polarizers can indeed develop a focus shift. I've had it happen with maybe two 52mm Nikon polarizers. Probably it is because of the sandwich construction of polarizers. Mine had been subjected to extremes of temperature, and a difference in the coefficient of expansion between metal, glass, and plastic might have been responsible.
Perhaps try focusing with GG and then try inserting a film back but put a piece of tape or frosted/waxpaper in the place of the film and check the focus on that. That can rule out the groundglass being too close. Use Wide open lens and focus on a flashlight or other light source to be sure.
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