Neg issues that developed during printing

canuhead · Feb 3, 2020

Kino said:
OP states he is setting up a new darkroom. I merely asked him to check his heat IR filter. If he bought a used enlarger and this is the first time using it extensively, there is the slight chance that the heat absorbing glass could be missing . It is worth checking and it is a variable that is easy to eliminate with just a few minutes work.

Why not be sure?

can't argue with this. eliminate variables, one by one until left with the problem. hopefully

Mainecoonmaniac · Feb 3, 2020

Kino said:
I remember printing in a very cold darkroom in college using ceramic coated metal trays. When I would put the print in the stop, it would practically scream; very startling the first time!

Like putting live lobsters in a boiling pot?

Kino · Feb 3, 2020

Mainecoonmaniac said:
Like putting live lobsters in a boiling pot?

Exactly...

Bikerider · Feb 4, 2020

Kino said:
I remember printing in a very cold darkroom in college using ceramic coated metal trays. When I would put the print in the stop, it would practically scream; very startling the first time!

That would be with fibre based paper where the stop bath would be creating gas when reacting with the residual developer which had been absorbed in the paper base . It cannot happen with resin coated. It was only doing it's job.

The same effect happens with film developer but on a smaller scale, except with colour developing in a JOBO rotary tank. Pressure can build up and force the 'push on' lid to pop off.

Jamie A Cowan · Feb 4, 2020

OK so there is no IR filter as far as I can see.
Can someone tell me where it should be? -
There is no glass at the end of the bulb, is this normal?

I printed two images that night, one 7 times and one 3 times, the image printed 7 times suffered no ill effect, however it is possible that I did not wipe that particular negative with the lens cloth.
Im not sure i want to wipe the unaffected neg for experiment sake.

I will place a dud/duff/crap neg in the enlarger and keep the modelling light on for lets say 10min - unless anyone tells me that is a bad idea.

Both used HP5 processed at the same commercial establishment (Aperture London) at the same time.

I do use the focusing switch quite a lot during the session. IE the bulb can be on for a minute or more at any time. IS this not best practice?

Jamie A Cowan · Feb 4, 2020

Kino said:
Just to confirm the lamp is the proper voltage/wattage and to see if the IR heat filter (illustrated in the web page you shared) is in place and not cracked or badly faded.

I cant find an IR filter.

Jamie A Cowan · Feb 4, 2020

Q. I had the negative in the neg carrier both ways round, IE emulsion side up and also emulsion side down, would this have an effect on the potential overheating issue?

Jamie

Kino · Feb 4, 2020

It's on the mixing chamber.

The white box with brass-looking hold down leaf spring. VERY CAREFULLY remove it and look at the side of the box. There should be an IR head absorbing glass in the window facing the dichroic filters and lamphouse.

Jamie A Cowan · Feb 4, 2020

IR Glass seems all correct.
@Kino - Thanks !

Kino · Feb 4, 2020

OK! Eliminate that possibility.

Jamie A Cowan · Feb 4, 2020

Thanks Kino.

I'd still like everyones opinion, if the focus light is left on for minutes at a time (...even with the IR filter) could have affected the negative?

For example 10 mins continuously?

(I will do an experiment later today, with the same batch of negatives)

jeffreyg · Feb 4, 2020

I have been developing and printing for almost fifty years and have never run into the problem you presented. My guess is whatever happened did so while the emulsion was wet or was a wet substance that got on those frames after processing possibly on the cloth you used. I never wipe negatives nor do I use acid stop with film. My suggestion is to move on and avoid acid stop and use one of the canned air products to blow any dust from thoroughly dry film. Those appear to be nice images and can be salvaged by scanning and repairing with PhotoShop or other software. If you want a silver print you can do the repairs digitally, revert to negative, (reverse horizontally) and print it on Pictorico transparent film and contact print in the darkroom on your photographic paper. All is not lost.

http://www.jeffreyglasser.com/

http://www.sculptureandphotography.com/

canuhead · Feb 4, 2020

There should be next to zero chance of heat reaching the negative to the point that it will cause damage. The v35 is a diffusion machine and I've never had this problem printing with mine, or any condenser enlarger either, so there's that to consider.

If one print showed no spots, I would take lens wipe, and give the film a swipe as that may very well be the issue. The negative will be fine with wipes with a clean lens cloth.

koraks · Feb 4, 2020

Jamie A Cowan said:
Thanks Kino.

I'd still like everyones opinion, if the focus light is left on for minutes at a time (...even with the IR filter) could have affected the negative?

For example 10 mins continuously?

(I will do an experiment later today, with the same batch of negatives)

Worst that can happen is that the negative warps due to the heat. Which usually is a reversible thing. They call it 'popping' as the negative tends to pop into a convex shape, just like in a slide projector. I've never heard of emulsion damage due to having a negative in an enlarger, can't think of a failure mode/mechanism that would result in this, etc.

jeffreyg said:
I have been developing and printing for almost fifty years and have never run into the problem you presented. My guess is whatever happened did so while the emulsion was wet or was a wet substance that got on those frames after processing possibly on the cloth you used.

Agree. The damage looks like one of three causes:
1. Bubbles between the film and the emulsion which were torn open when the negative was wiped
2. Something in the wiping cloth catching on the emulsion, tearing it away in places.
3. Film wiped as the emulsion was wet, essentially exacerbating option 2.

Option 1 would point towards a major problem in film manufacturing or processing.
Options 2 & 3 would point towards a major incompatibility between the wiping cloth and film, or an erroneous wetting of the film before it was touched mechanically (obviously never re-wet film if there is no compelling need to, which usually there isn't).

With today's well-hardened emulsions, the use of a stop bath generally does not cause problems, even under adverse conditions. I think PE has posted about this earlier and my personal experience confirms it. I have yet to come across a case of a modern camera film being harmed this way. The only situation I know of is very old-style poorly hardened film (the latest on the market was Efke 25, long gone now) processed in deep tanks with a fairly strong stop bath.

This leaves either another issue in the processing, but I can't think of any, apart perhaps from extreme temperature variations during processing (but we'd have to be talking really *extreme* here for this kind of defect to show up).

A failure mode in film manufacturing I could imagine is contamination of the film either before or after the subbing layer was put on, or frothing of the subbing emulsion, leaving tiny spots where the subbing didn't adhere to the film or the emulsion not adhering to the subbing.

I'd consider contacting Ilford and provide them with a sample of the problem. They appear to be pretty good at troubleshooting arcane film defects, either caused by manufacturing defects or caused by problems during processing.

In any case, I wouldn't waste time trying to find the cause in the enlarger. The chance of that being the cause is virtually zero.

pwitkop · Feb 4, 2020

Mainecoonmaniac said:
I remember while I was an undergrad, my professor said he never uses stop bath only a water rinse because the shock from residual alkaline developer to acidic stop bath causes pinholes. Since then, I've never used a stop bath just a rinse. I've haven't verified his theory though. Stop bath is super cheap so cost wise, it not an issue for me. I do notice in BW printing, when the print is out of the developer then goes into an acetic acid stop bath, sometimes I hear squeaking from the residual print developer reacting with the stop bath. I always guessed that the noise is C02 gas escaping from the print. Again, I haven't verified that.

That's absolutely possible but in practice it only happens when the stop is mixed too strong. The pH of the developer would also play a part. It looks like bubbles to me too.

The gotcha is the print without the marks

pwitkop · Feb 4, 2020

koraks said:
Agree. The damage looks like one of three causes:
1. Bubbles between the film and the emulsion which were torn open when the negative was wiped
2. Something in the wiping cloth catching on the emulsion, tearing it away in places.
3. Film wiped as the emulsion was wet, essentially exacerbating option 2.

I think you're right, my money is on 1. I doubt you could get enough heat to damage the emulsion without it being fairly obvious, especially from an enlarger bulb, and that was my other thought.

canuhead · Feb 4, 2020

which negative carrier are you using ? the glassless one, or the carrier with glass on top ?

Jamie A Cowan · Feb 4, 2020

25mm x 37mm with the newton glass on top.
@canuhead

reddesert · Feb 5, 2020

Surely negative popping (leading to bad focus) from heat would be visible long before emulsion damage, but now that we know the IR absorbing glass is present that seems unlikely anyway.

I don't think wiping negatives with a lens cloth is a good idea. Negatives are a lot softer than glass+coating. Negatives should be clean and not require wiping with pressure. A gentle pass with a brush (there are brushes for this purpose, or a good quality small artist's paintbrush) can be used to pick off dust and fine hairs etc that may have settled on the negative.

Patrick Robert James · Feb 5, 2020

That very clearly looks like abrasion on the emulsion to me. How did you wipe the negs?

Never try to "wipe" the emulsion side. Blow it off or use a brush. If you are wiping the base side, don't rub the emulsion side. When I clean a 35mm neg that has water spots, I hold the neg on a clean piece of paper emulsion down, breath on it, and wipe with a microfiber one time while holding the neg firmly so it doesn't move. Dust should be blown off or removed with an anti static brush.

Hope that helps you.

jtk · Feb 5, 2020

Discard the "lens cloth", whatever that is. Use proper lens tissue on lenses, never cloth. Kodak sold tissue, your opthalmologist does as well.

Tissue on film is bad practice...as bad as cloth..internet "gifts" of cloth are rampant. Get an expensive wide camel hair brush.

Use of cloth is bad enough but there may also be unmentioned hygiene issues ...such as cosmetic/medical dust on skin or hair that would show up occasionally, even if rarely.

warden · Feb 5, 2020

Jamie A Cowan said:
I don't remember doing anything to the negative, could this have happened by me wiping of dust with a lens cloth?

The problem sure doesn't look like the result of wiping to me. Whenever I've had a problem with cleaning a negative the result was long directional scratches rather than the craters you've shared. I'm no expert but since there is no apparent directionality to the damage my first thought would be something pressed down on the negative creating this effect. Any chance of that? I also like the idea shared of some liquid spraying on the negative but I've done that as well and the result looked like droplets rather than the odd pin pricks here.

jtk · Feb 5, 2020

jawarden said:
The problem sure doesn't look like the result of wiping to me. Whenever I've had a problem with cleaning a negative the result was long directional scratches rather than the craters you've shared. I'm no expert but since there is no apparent directionality to the damage my first thought would be something pressed down on the negative creating this effect. Any chance of that? I also like the idea shared of some liquid spraying on the negative but I've done that as well and the result looked like droplets rather than the odd pin pricks here.

I agree that "wiping" doesn't seem to be the problem, but tolerance of that bad practice does suggest possibility of other issues, such as hygiene .

Jamie A Cowan · Feb 6, 2020

Hey @jtk can you elaborate on the word Hygiene please?

pentaxuser · Feb 6, 2020

Dust is often a problem in a darkroom. There are several ways to remove it. A microfibre cloth is one certainly. I got one from Ilford on its factory tour a few years ago and I have used it without problems. It needs to be placed back in its bag once you have wiped the negative to avoid any possibility that it can sit on a work surface and pick up remnants of other liquids which are then transferred to the cloth . Another method is a can of air blown across the negative. The cans are powerful enough to be held far enough away from the negative to avoid the mist that some say is ejected from the nozzle.

Third and maybe best way is a small battery operated "hoover" like tube that has a brush on its end. You simply run the brush over the negative and it sucks up the dust. I have no idea whether such "hoovers" are still available. I got mine secondhand about 10 years ago from someone selling his darkroom.

Clearly lens cloths are impregnated with liquid to do their job on lenses. It would appear that this may be harmful to the surface of negatives so better not to take the chance.

What you have may have been a one-off anyway and neither you nor we will ever get to the bottom of it. However darkroom hygiene is worth being particular about even down to ensuring that your hands at all times prior to handling negatives are as clean and dry as surgeons

pentaxuser

Neg issues that developed during printing

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