Spots on Negatives (Water/Dust/PhotoFlo ) - Sudden Appearance after a month away

[chakra]

Hi,

I am having a vexing problem of numerous white spots on negatives that has suddenly appeared in my workflow. I was away from my darkroom about a month and a half, before which I was routinely developing Tri-x in Rodinal, D76H and Xtol and TMAX 400 in D76H.
A water stop (3 changes) was followed by a 2x clearing time (3x for TMAX) in TF-4 or TF-3 for fixing. Washing was with the Ilford 5+10+20 method. This was followed by a rinse in DI water and then a minutes soak in Kodak Photo Flo 200 at 1:200 in DI water. The negs are then hung up to dry either in a wooden cabinet or in my darkroom after being generously sprayed with water using an atomizer.

My negatives were usually clean with only the occasional spot that would show up during scanning and rarely during printing.

I filter all my water through an iron and sediment filters. I also have water demineralizer that I use to make DI water. The municipal water supply here is very hard, high in iron and quite variable.

After the break I returned to develop some Fuji Neopan 100 SS in Kodak D76 and D76H as usual and the almost all frames turned out heavily spotted. There were both large white spots and tiny ones spread all over. Two example 4000 dpi scans that show both large and small spots are attached.

1. I developed using water from my deionizer only and the spots were still there.
2. I made fresh fix my (TF-3 stock solution bottle was half empty while I was away) thinking that the fix may have gone bad. No improvement.
3. I made a different fix (Ryuji´s Neutral Rapid Fixer). And filtered every solution through cotton balls in a funnel. Spots were still there.
4. I played with different dilutions of photo-flo. From a few drops in DI to the recommended 1:200. Spots still.

I pulled a relatively unimportant strip out of its foldlock sleeve and shone light on it at different angles for ages. The base side was clean. No dust.
The emulsion side had tiny physical protrusions, the easily visible ones corresponded to the large white dots in the scan.
Then, really frustrated, I resoaked the strip in photo Flo and wiped it with a cotton ball a few times. On drying and rescanning some of the spots had moved around. So they could not be bound to the emulsion nor have chemically reacted with it.

My Photo FLo bottle looks clean and on shining light I can´t see crud or sediment in my water. Maybe a couple of specs of dust if I pore over it forever.

But on studying the negs with a loupe and generally observing the process after the neg is hung up to dry, it appears that these maybe tiny bubbles that won´t sheet off the film. If there is dust seeding the bubbles, I can´t tell; but my darkroom has so far been rather free of dust and routinely washed down.

Can anyone suggest a way to trouble shoot this as it´s driving me nuts.
Thank You!
Santanu

 

[R gould]

Try adding a few drops of isopfopyl alcohol to your final photoflo rinse,or using either tetenal mirosol antistatic or rollei wetting agent. Certainly the isopropl alcohol in photoflo works,I have used it for sometime since I had a lot of problems with white spots, since using the few drops no more problems, try it,Richard

 

[el wacho]

that would drive me insane... and it has.

i experienced different spots in my process. i had to substitute every substitutable element in the process and eventually the spots went away (fingers crossed) when i suspected the local sodium carbonate might be a little impure so i switch to ( impure ) local sodium hydroxide and there were no spots. so i can't directly help you with your problem but i can tell you that if you continue to eliminate areas of problems you hopefully should bump into the cause... well i hope you find what is causing the problem because it's a real nightmare.

wishing you the best.

 

[el wacho]

ps from my understanding the photoflo is there to facilitate the flow of water off the negs by 'breaking' the surface tension of the water ( i could be wrong ) so i wouldn't let it soak into the emulsion - only the distilled water should soak in then photoflo it at the last minute and hang them up.

 

[el wacho]

looking at the white spots, they don't appear to be bubbles. they have somewhat jagged shapes... and if they moved after a soak and scrub with cotton wool... well from this distance it sounds superfical... food for thought.

 

[R gould]

Another tip I got a long time ago,and use today, is to double wipe the back of the film with a sheet of kitchen roll, this does not scratch the negatives, speeds drying and the negatives dry clean,Richard

 

[Doremus Scudder]

Sounds frustrating!

From the scans, it looks like dust on the negatives... You need to find where it is coming from.

First, examine the negatives straight out of the fix for spots. Clip off a length and get out the loupe and the bright lights. If you have spots at this stage, you have junk in your processing solutions. Check your water source and filter all your solutions using clean paper coffee filters, not cotton balls. It could be that you are introducing broken cotton fibers into your solutions by filtering with cotton. Try fixing a clip without developing and see what happens too. Don't discount a film defect either, try a different and reputable brand. Mix your solutions a day ahead and filter them as above before use (freshly-mixed solutions can have undissolved solids in them).

If the negs pass test one, you know you have to look at the second stage. Check the negatives after each step with loupe and light to find where the spots appear. If they are alright after the wash then check your deionized water (filter it as above and/or get new, commercially-distilled water to test with). Mix your photoflo as per instructions and then filter it as well. Treat the film in photoflo and hang them up to dry; forget the misting (that might be a source of crud too and it's superfluous is you do the photoflo treatment correctly). If there are bubbles on the film that don't sheet out, you are mixing the photoflo incorrectly. Don't wipe your film with anything, don't squeegee, don't use fingers, just take it out of the (hopefully) clean photoflo and hang it up.

Make sure the air in your drying area is dust-free. Run the hot water to create some steam and settle dust before processing, don't stir things up, etc. Leave the room after you hang the film and slowly close the door; don't come back till the film is dry. (This is all overkill, but at this point, you need some it seems...)

You'll likely find your culprit where you least suspect it, so be methodical and check everything, even if you are "sure" it isn't the problem.

Best and good luck,

Doremus Scudder
www.DoremusScudder.com

 

[chakra]

@Richard Gould:
Richard , I´ll try out your suggestion of using Isopropyl Alcohol in the final wetting rinse and see how it works. I imagine the alcohol will speed up drying too. I am quite nervous about touching the negatives and hopefully the emulsion side will dry fine. Thanks

@el wacho: Hi, I am really going through all possible substitutions. Hopefully the simple ones of crud somewhere in the process will work. However if it´s due to some trace impurity that is precipitating out or catalyzing something else´s precipitation; that´s tougher to diagnose. Thanks

 

[chakra]

@Doremus
Thanks for the detailed response. It does look like dust/crud to me. The solutions have all been sitting for 48hrs or so. But I will pass everything through filter papers from a chemistry store and redo the development. 5 micron filtration should do it, perhaps even overkill. Every pixel in a 4000 dpi scan should be ((25.4mm*1000)/4000) = 6.35 microns. And the spots are a few pixels wide.

If that solves it, then it must be my filters. The municipal water supply may have changed by a lot. If it doesn´t then I´ll have to go stage by stage as you suggested. Thanks a lot.

 

[R gould]

Chakra, never touch the emulsion side, but most problems seem to occur on the "Shiny" side,and I find tha carefully wiping that side twice with a folded up sheet of kitchen roll both speeds up drying to a very short time and while the film is wet removes potential problems, whilst the alcohol give an antistatic layer, so that the film attracts less dust while drying, You can also try using drysonal from tetenal, which reduces drying time to a few minutes.While I can't promise that this will cure the problem entirely it should certainly very much reduce it,Richard

 

[el wacho]

i could be wrong but something tells me that it's not dust due to the shape. it looks a little more crystaline. also i've not tested this but someone else here said coffee filters aren't fine enough... regarding using cotton, i've been using this method and to ensure no cotton particles ( as with all fitlers ) you run some water through the system and discard. i use this water for washing film only though. hope this helps