light leak or dev error?

karrlander · Jul 14, 2013

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?

/robban

StoneNYC · Jul 14, 2013

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?

karrlander · Jul 14, 2013

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.

bdial · Jul 14, 2013

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?

fotch · Jul 14, 2013

Hello and welcome to APUG! I have no opinion of the your problem and will read what others post with interest. Good luck.

Vilk · Jul 14, 2013

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...

Mark Feldstein · Jul 14, 2013

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".

Take it light ;>0
Mark

karrlander · Jul 14, 2013

bdial said:
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?

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.
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:

karrlander · Jul 14, 2013

Mark Feldstein said:
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 firs

...

Take it light ;>0
Mark

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.
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.

karrlander · Jul 14, 2013

Vilk said:
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...

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?

Mark Feldstein · Jul 14, 2013

As an anecdote, I had a roll of VPS ISO 160 Vericolor (from the same emulsion batch) that had been stored in an A-12 magazine and in a metal camera case run through 6 scanners on a cross-country trip. It was dip and dunked by my lab. The film showed base side emulsion fog as did two blank rolls that hadnt been loaded in a magazine. The Kodak Tech. Rep was concerned enough to send them to Rochester NY for a look. This was about the time the FAA was saying their scanners only affected film with an ISO of 1600 or higher. (Right).

Since the effects of radiation are cumulative, Kodak came back and told us the film had been fogged by x-rays, probably from airport scanning since Kodak used transportation and storage methods that did not involve x-rays. Kodak and I contacted the FAA and requested that they retest their earlier results although then (and now) they provided for hand inspection of film without scanning it. The FAA denied our request and continued to deny that medium and low speed films were affected in any way by even multiple radiation exposures.

They subsequently revised their tune and without agreeing or admitting any error and finally acknowledged that base side emulsion fog could occur in all films and continued to provide for hand-inspection of any film type/speed.

See if this problem occurred on another roll of the same batch number and from another processor although if it doesn't bleed over the frames into the border, it's probably not fogged but I'd agree it's processing.

clayne · Jul 14, 2013

Make sure you're not topping off the tank as well. There should be some airspace for the liquid to displace.

polyglot · Jul 14, 2013

It's a scanning failure; you've not set your black-point correctly. Red shadows in Portra are a classic symptom of using the mask colour as the black point. Have a read of the C41-scan howto in the FAQ in my signature. The gradient is usually a function of flare inside the scanner.

The subject's face is also under-exposed. With normal contrast, the face is going to be pretty dim with the background set to black. Bringing the skin tones up causes the contrast to be unnaturally high (the second scan) or the background to fail to be black (first scan). There is no cure for that other than better light.

As to agitation, C41 expects constant agitation through the whole process. Inversion should be fine, but don't do it once per minute, keep going for the whole 3:15.

Andrew O'Neill · Jul 14, 2013

If you are in a darkroom, lift the film in/out of the tank a few times every minute. If you are not in a darkroom, invert the tank a couple of times every minute. I rarely could get decent results when using that silly little stick. I believe that the film edges are receiving more agitation than the centre, building up more density.

Vilk · Jul 14, 2013

karrlander said:
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?

perhaps it's one of those rare occasions when negative thinking would yield more useful results...

karrlander · Jul 15, 2013

Thanks a lot everyone. Lots of information and things to start working with. Looks like I have to get myself a good scanner after all and learn how to run it. And work a little more on my dev process to get all the bits and pieces together. I will keep the thread updated with the results!

StoneNYC · Jul 15, 2013

Epson v750

~Stone | Sent w/ iPhone using Tapatalk

karrlander · Jul 15, 2013

StoneNYC said:
Epson v750

~Stone | Sent w/ iPhone using Tapatalk

That would be a nice one but my wife says she want food every night. I can get a Epson V500 for a really nice price, would it be a good start or will I be dissapointed and want to upgrade shortly?

clayne · Jul 15, 2013

You will be disappointed with any of those flatbed scanners. I hate to break it to you, but unfortunately you will only be truly satisfied using a dedicated film scanner.

Now you're going to hear from a bunch of people who will tell you they get great results with the Epson, etc. through various games they play with the scanner, but it's a far cry from a 4000 dpi medium format capable scanner (which will also do 135 format). Plan on 2k$ budget.

Amusingly though, if you scan 5x7 and 8x10 prints on a v500 or v700 it'll do pretty good - but that's because they've already had the hard work done for them ahead of time. Don't fall into the flatbed scanner trap - they're severely lacking.

karrlander · Jul 15, 2013

clayne said:
You will be disappointed with any of those flatbed scanners. I hate to break it to you, but unfortunately you will only be truly satisfied using a dedicated film scanner.

Now you're going to hear from a bunch of people who will tell you they get great results with the Epson, etc. through various games they play with the scanner, but it's a far cry from a 4000 dpi medium format capable scanner (which will also do 135 format). Plan on 2k$ budget.

Amusingly though, if you scan 5x7 and 8x10 prints on a v500 or v700 it'll do pretty good - but that's because they've already had the hard work done for them ahead of time. Don't fall into the flatbed scanner trap - they're severely lacking.

I know, but I can't put that much money in a scanner. I dont get paid for my film shooting, the DSLR stands for the income. Someday maybe I can get one but for now I have to do with the second best.

clayne · Jul 15, 2013

karrlander said:
I know, but I can't put that much money in a scanner. I dont get paid for my film shooting, the DSLR stands for the income. Someday maybe I can get one but for now I have to do with the second best.

You could always use the medium format route for income as well. May be a bit of a chicken before the egg but surely you could sell some other stuff to generate funds? The Epson would be a sunk cost you could be using for a Plustek or Coolscan.

karrlander · Jul 15, 2013

clayne said:
You could always use the medium format route for income as well. May be a bit of a chicken before the egg but surely you could sell some other stuff to generate funds? The Epson would be a sunk cost you could be using for a Plustek or Coolscan.

If only that was true! But as a full time crime scene photographer working for the swedish police I have a hard time so see where my analouge fetish would fit in.

polyglot · Jul 15, 2013

karrlander said:
If only that was true! But as a full time crime scene photographer working for the swedish police I have a hard time so see where my analouge fetish would fit in.

oooh, gritty

I take it you're not allowed to use images from work (without any personal or identifying details) for personal artistic purposes? You have the access to put together the most fantastic gallery show.

karrlander · Jul 15, 2013

polyglot said:
oooh, gritty

I take it you're not allowed to use images from work (without any personal or identifying details) for personal artistic purposes? You have the access to put together the most fantastic gallery show.

Well, maybe I have a couple of nice ones. But most of the time it's not that fancy, more technical with special lightning, fluorescens, IR/UV and stuff like that. And a lot of exact and detailed documentation.

bvy · Jul 15, 2013

clayne said:
You will be disappointed with any of those flatbed scanners. I hate to break it to you, but unfortunately you will only be truly satisfied using a dedicated film scanner.

Now you're going to hear from a bunch of people who will tell you they get great results with the Epson, etc. through various games they play with the scanner, but it's a far cry from a 4000 dpi medium format capable scanner (which will also do 135 format). Plan on 2k$ budget.

Amusingly though, if you scan 5x7 and 8x10 prints on a v500 or v700 it'll do pretty good - but that's because they've already had the hard work done for them ahead of time. Don't fall into the flatbed scanner trap - they're severely lacking.

You make it sound hopeless. For the price, a flatbed scanner (I have the Epson V500) will give consistent and acceptable results. No, you're not going to squeeze every grain of silver out of your film with a $200 appliance, but for medium sized web images or small prints, they do a respectable job.

That said, I've mostly given up scanning in favor of color printing anyway. Still I rely heavily on my flatbed scanner; it lets me scan a roll of film quickly and review the frames for composition, sharpness, density, etc. The results are good enough to help me decide what I want to enlarge.

light leak or dev error?

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