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HI Guys,
I got some of my negatives back form the lab ... I´m doing here some color correction but on the edge of the picture you will see a vignette... What do you think - how can avoid this ?
Portra 160
by the way a massive green cast - picture 6x6 negatives vs 4x5 - same lab - portra 400 on 6x6 - portra 160 on 4x5
THX !
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That doesn't look like vignetting, but like the surge patern caused by a rotation development system. My guess is that the lab used a Jobo system and for one reason or the other haven't got their process under control. There is nothing much you can do about it, except returning to the lab and show them the issue. If necessary and possible, try a different lab.
Vignetting would look like completely dark corners or part of a circle or a more or less a straight line at the upper or lower side of the image. It is often caused by running out image circle of the specific lens, a lens shade that is intruding into the image or a saggy bellows obscuring part of the picture. This can be checked by looking through the clipped corners of the ground glass with an open shutter and a closed aperture. When you can see the full aperture through the clipped corners you are fine, if part of the aperture is obscured, you have an issue. And when your camera doesn't have clipped corners, look into the lens form the front side and check if you can see the complete groundglass and some more...
Thank you so much for this information... yes I also thought it could be a development issue - i will talk to the lab.
(I have to say that I use my 125mm 90 mm and 150mm 4x5 lenses and stop down to f45... but as you said - this could be a development error.....)
Why areyou stopping down to F 45? If they’re not classic lenses they’re sharpest at F 22 if classic that’s a different story. You’re shooting at infinity so you don’t need the DOF, Or use a little front tilt.
What thing can cause this problem during Jobo rotation development, rotation speeds? I had the similar problem when I developed my color film (Kodak Portra NC 160) using a fresh C41 kit. Thanks!
Quote:
Originally Posted by Huub
i have a
apo sironar-s 150mm
fujinon w 125mm
nikkor sw 90mm
fujinon w 300mm
i always thought f45 will be the best aperture for those lenses... ???
Diffraction limited at f22.Quote:
Originally Posted by gmfotografie
okay... but when i set my front an rear standard correctly - sharp in the nearest point and sharp in the most distant point --- and you get the middle unsharp when you look the ground glas -> we have to close the aperture... does f22 be okay to get a good result if you want to have near to far sharp ?
I am not sure what can be the cause this problem, but i struggled with it in black and white for years. Often the negatives were perfect, but frequently there were misses as well. Tried al sorts of things, like changing rotation speed, pre-soaking, changing film, changing developer, but those surge paterns kept appearing. In the end i gave up and changed to a replenishment system with XTOL, reversing the tanks the good old fashioned way, using 1.25 and 2.5 L of fluid. This solved the problem in B&W, but for colour work this ain't an option of course.Quote:
Originally Posted by diversey
Thank you - but i Think they have a big problem.... also my negatives are completely green... and I told them to develop portra 160