Stain embedded in negative - Water stain? Chemical?

Hi all,

I recently developed some film and discovered a strange aberration that I cannot explain. I've been developing my own B+W film for 4 years, and I've encountered this issue twice now. Different film stocks, different camera.

Here are two consecutive frames from a roll of Ilford HP5+ processed in Ilfotec-HC using the standard recipe from Massive Dev Chart (I also used Ilfostop Stop Bath, Ilford Rapid Fixer, and PhotoFlo as my rinse aid).



As you can see, there appears to be what *looks like* a water stain across both frames. But when I look at the negative, tilting it to catch the light, I can't see it on either the glossy side or on the emulsion side. It seems to be embedded into the emulsion. If I view the negative over a light table, I'm able to see the dark stain as if it were part of the image. I've tried gently wiping both sides of the negative with some PEC-PAD photo wipes to no avail.

Does anyone know what could cause this, and how to prevent it?

Thanks in advance!
Joey

It could still be a water stain, even if you cannot see it on the surface on either side.

Try re-processing the negative by doing a distilled water bath at normal developing temperature, re-fixing and rewashing the negative with photoflo in distilled water. It might go away.

I often see this on motion picture film that didn't have the water removed sufficiently by the vacuum squeegee just before it went into the drying cabinet. We simply run the roll back through the processor once more and it tends to go away. The squeegee on our processing machine is a temperamental thing...

Kino said:

Try re-processing the negative by doing a distilled water bath at normal developing temperature, re-fixing and rewashing the negative with photoflo in distilled water. It might go away.

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Thanks so much, Kino! Any suggestion as to how long I should leave it in the distilled water bath?

It looks like a photo flow issue, if its on the base side it will easily wash off , if on the emulsion side not so easy - I would use room temp distilled water and gently try a very soft cloth on base side to see if it comes off.

This usually is a result of the photoflow being too concentrated, are you mixing the photoflow in distilled water?

Bob Carnie said:

This usually is a result of the photoflow being too concentrated, are you mixing the photoflow in distilled water?

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You may be on to something, as I think this time when I added the PhotoFlo, I didn't do my usual mild agitation to distribute it throughout the tank (I was interrupted at the end of the process). I'll have to remember to be more careful about this. I never thought it could be the PhotoFlo itself. Thanks for the tip!

Joey Pasco said:

Thanks so much, Kino! Any suggestion as to how long I should leave it in the distilled water bath?

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About your normal development time and temp; need to let the emulsion re-swell to allow the stain to migrate out. Good luck!

BTW: it IS photoflo that is causing your problem. If the simple fix Bob suggests doesn't work, try what I suggested...

you only need 1 drop or 2 of photoflo.

jnanian said:

you only need 1 drop or 2 of photoflo.

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This is about what I use, but I'm not too careful about it; I'm probably using a little too much.

It's really easy to use too much photoflo using the drop method.

Rather than use drops, take the time to follow the instructions and store any excess solution. This is a much better way to go.

Joey Pasco said:

This is about what I use, but I'm not too careful about it; I'm probably using a little too much.

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sounds good joey
worked for a guy who used to have a 5 gallon container with a spigot that he'd fill with photo flo
he used to drain some off when he washed his film. it always seemed too concentrated to me, and if
he didn't use it all up fast enough it grew mold or something funky in it ...
a few drips/drops has always been good to me besides that way, 1 bottle lasts about 20 years !

good luck rewashing &c your film !

john

I mix it 1 gallon at a time by putting 1/600th of a gallon (6 milliliters) in a gallon jug of water.
I've been doing it for years and still have plenty of concentrate left.
No problems so far with it becoming a biology experiment, I use once and discard.

If you live in an area with hard water, it may be a mineral deposit. If the above remedies don't work, try a long soak (~10 minutes) in stop bath and then rinse and soak for a few minutes in distilled water/Photo Flo.

Photo Flo only takes a few seconds to do its work, but if you need to get minerals out of the emulsion, it's a good idea to extend the final rinse in distilled water/Phot Flo to a few minutes (3-5) to ensure that enough of the minerals diffuse out of the emulsion.

And do try to mix the Photo Flo at the recommended dilution or a bit less

Best,

Doremus

I was actually having this exact problem. I mixed my photo-flo to the manufacturer specifications with distilled water and I would get the occasional drying mark. I increased the dilution and spots are gone.

Kodak recommends 200 parts water + 1 part concentrate

bdial just reported that they're using about 630 parts water + 1 part concentrate successfully

I don't know how much I diluted mine because I didn't really measure, but it's much less dilute than bidal's solution. I'd estimate something like 300-400 parts water + 1 part concentrate.

bdial said:

I mix it 1 gallon at a time by putting 1/600th of a gallon (6 milliliters) in a gallon jug of water.
I've been doing it for years and still have plenty of concentrate left.
No problems so far with it becoming a biology experiment, I use once and discard.

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Are you using Photo-flo 200 or is it Photo-flo 600?

MattKing said:

Are you using Photo-flo 200 or is it Photo-flo 600?

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I miss-spoke, it's 200 that I have currently (just checked). My method is the same though, 1/xxx of a gallon of concentrate into 1 gallon of distilled for the working stock, and that is used once.

As I recall, the 600 formulation is more common in Europe, for whatever reason, I think the difference is discussed in here somewhere, but it's a pretty old thread, I believe.

Thanks for catching me on that.

bdial said:

As I recall, the 600 formulation is more common in Europe, for whatever reason, I think the difference is discussed in here somewhere, but it's a pretty old thread, I believe.

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So you are actually using it at the manufacturer's recommended dilution.
The 600 formulation was packaged for commercial lab use. It is relatively toxic. If you are an individual user and have a bottle, you are set for life!