light leak or dev error?
Hi! I've read this forum for a little while and enjoyed a lot of good tips and trix. Just started to develop color negative and runned into some problem. As you can see on the pic I got some strange things going on in the left and right part of the pic. I doesn't show on all frames in the roll, at least not what I can see. This shot is taken with studio flash and a grey background so it becomes very obvious. I haven't had this problem with b/w. I develop in Digibase C41 and have tried both 38 degrees and 25 degrees.
Is this a light leak maybe from the roll not getting rolled up tight enough or is it a dev error? I have tried to agitate both by turning my paterson tank upside down and by just turning the little stick. The negs got better when I stopped turning it every 30 sec and just twisted the stick every 1 min in 25 degrees and 13 min. The film is Kodak Portra 160 and is shot with a Mamiya 645 AFD II.
Does anyone have a clue?
is this OLD portra? it looks like light leak but could be age fogging too? or could be that this is a scan and you haven't set the black values properly?
The film is new so that shouldn't be the problem. I've tried to look at the neg but I can't see any differences outside the pic area and I think thats telling me that it's not a light leak. It can be a scan problem yes. I don't have a scanner so I use my DSLR and the color perfect plugin in PS. I will try have a friend scan the film to see if the problem comes from my "scanning" or not.
To me it looks like you may need to experiment a little more with the agitation.
Are you twisting the stick back and forth, or just one direction?
Also, how did the negs change in going from 30 seconds to one minute?
Hello and welcome to APUG! I have no opinion of the your problem and will read what others post with interest. Good luck.
i saw that on mine with solid backgrounds sometimes. solved with agitation: more frequent (the kodak 5 secs every 30 rather than the ilford 10 secs every 60). i understand the dev gets exhausted faster in the center than along the edges, where it has some fresh supply seeping over from beyond the frame edge...
Light leaks on rolled film (not 35mm) generally occur at either the first or last frames of the roll and are generally caused by operator error when loading or unloading a body or film magazine. On 35mm cassettes, it usually appears on the entire roll typically on reused reloaded cartridges or on the first and last frames if light trap is loose.
If it's a light leak on the body or film mag, light leaks are generally consistent throughout the entire roll although sometimes depending on the type of mag or body, they may appear worse towards the end of the roll as the take-up spool becomes thicker with exposed film.
The best place you can look for leaks is on the negatives or transparency stock and pay close attention to the film margins. Put them on a light box or some source of illumination. Look carefully for streaking in places that normally don't get exposed to light as the rest of the frames do since leaks tend to know no bounds so-to-speak and unlike something like lens flare which is bounded by the frame margins, they tend to overlap into areas that normally contain the frame number and should appear otherwise blank. And, like a broken shutter, they tend to show up fairly consistently from frame to frame in about the same place (although not always).
If you don't seem to have those things going on, THEN I'd look to the processing and tell us what kind of tank you're using, etc. as light leaks can occur there as well. Then again, I'd look for some kind of consistency there as well. All frames, some frames, all rolls, some rolls, just one roll?
As they say in Seattle (and Chicago sometimes)..."Where there's smoke, there's usually salmon". :D
Take it light ;>0
I think so also. I changed two things in the process at the same time (I know, stupid me) and that was from flipping the tank over to twisting the stick and from 30 sec to 1 min. I think the neg comes out a little "smother". They where much more grainy earlier. And I only turned it the same direction.
Originally Posted by bdial
I have now got a scan from a friend, it looks much better than my repro-attempt but I can still see some light parts on the sides in the pics. So, at least the error is there before I digitize it even if I did make it worse. :)
I shot a roll today trough my old Mamiya 645 just to see if it makes any difference. I will come back with those results when it's developed.
Here is the scan from my friend:
Thanks for all the input! I have checked the film on a lightbox and all margins looks perfectly clear to me so I guess that almost excludes light leaks.
Originally Posted by Mark Feldstein
I have switched tanks and tried one Jobo and one Paterson, no difference there. I think the problem gets worse on the last frames. But to really see that I have to shoot at least the first, middle and last shot under similiar conditions and the same subject/background. But that might be the way to go, I really don't like when I'm not understanding why things get F*d up. :)
Btw: the first 5 rolls I have tried all come from the same pack. I have no opened another pack but they are bought at the same time so probably from the same batch. Maybe I get another brand to try just to eliminate film error.
Thank's! Might absolutely be something to take into consideration. But if it's because of dev getting exhausted and that happends faster in the center the problem should not show up along the edges?
Originally Posted by Vilk