Water spots with and without deionised water?

[cliveh]

I thought the same thing at one time until I learned about differential drying marks. I was in denial for quite a while until I did some research. I’m sure many here could explain better than me. But when a drop of water continues to sit on an area of film and the rest of the film around it dries, the emulsion is “stretched” and causes the area around the drop to form a change in density.

Thus the need for a wetting agent to allow the film to dry evenly.

Perhaps you can explain how a water drop stretches the emulsion? And what happens when it dries?

 

[RalphLambrecht]

First of all, great to see this community still very active.

I've recently been battling a water spot problem as shown in the attached. I thought I got rid of this about two years back with a filter on my tap.

Of note:
- This is 120 HP5. Image attached is top right of frame 10 (6x6). Usually happens on one or more of last 3-4 frames.
- Up until the issue has appeared again, I have always used tap water for every step of the process. Upon seeing the water marks reappear a couple weeks ago, I decided to change to bottled deionised water just for an extra two Ilford washes (which includes 3 min soaks), then also for the wetting agent mix (1:200 or 5ml to 1l) which I leave the film to soak for another 2 mins.
- I have tried more and less wetting agent with no change, all else equal.
- Wetting agent is Ilfotol, brand new as are all chems.
- I use a Patterson tank and do everything in the tank until taking the reel out and putting it in a jug with the wetting solution.
- I then simply take the film off the reel and hang to dry, always ensuring there is an unbroken sheet of water on both sides of film. No squegee, no fingers.
- I dry in a bathroom after running shower. Usually have the radiator on and it's about 25-30C in there. Have tried with and without radiator though, down to about 10C ambient temp on this last roll.

Are water spots like these always from the crap in the water, or could it be from elsewhere? Interestingly, I can't actually see the marks on the surface of the film, neither emulsion or non-emulsion. So I was wondering if this could be happening during development and it's actually in the emulsion? Using deionised or distilled water for the whole process feels a step too far for me as I worry about the storage and recycling of all those 5L bottles. But if anyone really thinks it could be happening during dev I could give it a go for sanity. Conversely, as I am using deionised water now for the most critical stage for water spots with no change, seems like I could just as well go back to tap water.

I'm puzzled too. The only thing I can think of. omit the wetting agent altogether and just finish
rocessingafter washingwith a brief bath in deionized or better distilled water.

 

[Milpool]

Differential drying effects are explained in Kodak Tech Pub O-3 in the Film-Processing Tips section. It can potentially cause a localized emulsion deformation where one area dries at a different rate than an adjacent area. A water droplet (for example), which is why a wetting agent can help. This was always a best practice anyway. Somewhere along the line somebody who probably didn’t read the wetting agent instructions or something got the idea it was bad and that plain distilled water was the way to go. And the rest is history.

All that is not to say this is necessarily what cause the fault OP experienced. It could be unrelated.

 

[John Louis]

I should have attached this to this thread sooner. But here is my original thread from years ago detailing my struggle. Please read all the way to the end because there are a few updated times where I thought I had fixed my problem and I had not.

Brian, I'm taking your advice very seriously. I found it relatably funny how you kept thinking you'd fixed it. The angle trick makes a lot of sense, but I will report back this week hopefully.

What I am confused about now though is your distinction between differential drying marks and photoflo ones? My marks pictured actually look very, very similar to what you say were photoflo marks? So do you have a pic of what you believe are differential marks?

 

[brian steinberger]

Brian, I'm taking your advice very seriously. I found it relatably funny how you kept thinking you'd fixed it. The angle trick makes a lot of sense, but I will report back this week hopefully.

What I am confused about now though is your distinction between differential drying marks and photoflo ones? My marks pictured actually look very, very similar to what you say were pho So do you have a pic of what you believe are differential marks?

John, I’m assuming your marks of from too much Ilfotol in your case since you mentioned that was the wetting agent you used. I think you also mixed it at its recommended dilution? I’ve never used ilfotol but with photo flo for me the recommended dilution is too high as I mentioned before (1:200).

I will attach a picture of a differential drying mark this evening. Maybe a couple.

 

[John Louis]

John, I’m assuming your marks of from too much Ilfotol in your case since you mentioned that was the wetting agent you used. I think you also mixed it at its recommended dilution? I’ve never used ilfotol but with photo flo for me the recommended dilution is too high as I mentioned before (1:200).

I will attach a picture of a differential drying mark this evening. Maybe a couple.

Thanks. Also, since you mention you had these issues on last frames similar to me, wondering why cutting the film up did not solve your problem? Have you tried that again since? Wondering if that might be less faffy than hanging at an angle.

 

[brian steinberger]

Thanks. Also, since you mention you had these issues on last frames similar to me, wondering why cutting the film up did not solve your problem? Have you tried that again since? Wondering if that might be less faffy than hanging at an angle.

I believe I was doing that with Tri-x at the time for some reason. You could certainly try cutting your HP5 in half and after a dip in photo flo hang the two halves. I’ll attach a picture of my angle hanging setup tonight too.

 

[Maris]

Here's one I posted earlier. It still works for me .

I used to get the occasional drying mark but couldn't figure out why until I actually watched film dry after the wetting agent step. Watching film dry is, er, tedious but I noted that a drying mark formed every place a foam "blob" or liquid drop stopped moving down the film and then dried where it stopped. So I changed my technique.

Now I hang film initially as wet as possible to speed up liquid flow and I hang that film edge-on at a 45 degree angle, not vertical. The foam and liquid drops now only have to get across the film,and run along its bottom edge rather than down the full length face of the film. And if a drying mark should form it's on the edge of the film where there is no image.

 

[brian steinberger]

Ok, here is the photo I used in my original thread. This shows the result of too much photo flo.

I have two examples of differential drying marks. Both of these results happened when I was using distilled water only for final rinse. The effects are very hard to see. I've darkened these exmaples down to make it more visible. Basically a higher density area that shows as a lighter area along where a line of water would sit while the film around it dried.

And here are two pictures of how I hang my film at an angle. This is 120 obviously, with 35mm I put the wood block onto the floor and get it at as much of angle as I can. I'm in the process of trying to fabricate something to hold 35mm at a stronger angle.

I should note that for me I use 5 drops of photo flo in 500ml of water for 120 film. For 35mm I kept getting marks with only 5 drops so did some testing and found that I need 20 drops in 500ml of water for 35mm to flow off nicely.

Since I’ve gone over to this method I never see any type of marks anymore.

 

[koraks]

Perhaps you can explain how a water drop stretches the emulsion?

I see this happening occasionally on carbon transfer prints, but it's rare. Usually everything 'snaps into place' just fine when drying. But especially with prints transferred to paper, it very occasionally happens that there are density differences and indeed mechanical stresses in a spot where a single drop has lingered for a very long time, while the surrounding gelatin matrix dried. The density differences in this case are somewhat smooth and coincide with actual warping of the matrix; the gelatin really 'bunches up' in some places while being 'stretched out' in different ones.

I've never seen this happen on film, but it's conceivable. I wouldn't expect it to happen with the thin, hardened/tough emulsion on a modern film which doesn't swell that much in the first place. But maybe under extreme conditions it can happen, for instance when the wet time of the film was extremely long (hours), allowing it to swell more than it usually would. IDK.

 

[GLS]

Where? How much?

I got one from Amazon for about £100.

https://tinyurl.com/5x4jk25j

 

[John Louis]

Ok, here is the photo I used in my original thread. This shows the result of too much photo flo.

View attachment 372407

I have two examples of differential drying marks. Both of these results happened when I was using distilled water only for final rinse. The effects are very hard to see. I've darkened these exmaples down to make it more visible. Basically a higher density area that shows as a lighter area along where a line of water would sit while the film around it dried.

View attachment 372408

View attachment 372409

And here are two pictures of how I hang my film at an angle. This is 120 obviously, with 35mm I put the wood block onto the floor and get it at as much of angle as I can. I'm in the process of trying to fabricate something to hold 35mm at a stronger angle.

View attachment 372410
View attachment 372411

I should note that for me I use 5 drops of photo flo in 500ml of water for 120 film. For 35mm I kept getting marks with only 5 drops so did some testing and found that I need 20 drops in 500ml of water for 35mm to flow off nicely.

Since I’ve gone over to this method I never see any type of marks anymore.

Thanks Brian, I was going to ask where you got those clips from but found them. Exactly what I had in mind.

 

[dokko]

Thanks Brian, I was going to ask where you got those clips from but found them. Exactly what I had in mind.

had the same thought, seem to be Paterson Photographic Film Clips, right?
https://patersonphotographic.com/product/paterson-film-clip-set/

I usually use wooden cloth picks, sometimes I worry the film could slip out but so far this never happened. the paterson ones seems much more secure and certainly the better option if hanging at a 45deg angle.

I should add that my wash procedure is simply tap water for the wash and a single bath of deionised water (no wash aid) for the last rinse for 2-3 minutes, then hang them vertically. this gives me very clean negatives with most films (mostly Kodak Tri-X and T-Max in 135 and 120). the only ones I can remember having troubles was with Agfa Copex in clear skies. It never made sense to me, since in pure water there should be no possibility for drying marks, so I kinda put it off as film defects. but reading the Kodak tech pub I guess it could well be a differential drying marks problem, so I'll change some things next time.

thanks for sharing all the details of your journey brian, it was an interesting read and it made me think.

 

[John Louis]

Here's one I posted earlier. It still works for me .

I used to get the occasional drying mark but couldn't figure out why until I actually watched film dry after the wetting agent step. Watching film dry is, er, tedious but I noted that a drying mark formed every place a foam "blob" or liquid drop stopped moving down the film and then dried where it stopped. So I changed my technique.

Now I hang film initially as wet as possible to speed up liquid flow and I hang that film edge-on at a 45 degree angle, not vertical. The foam and liquid drops now only have to get across the film,and run along its bottom edge rather than down the full length face of the film. And if a drying mark should form it's on the edge of the film where there is no image.

Thanks Maris and sorry I can't respond to everyone. We may start a movement here with the angle idea lol

had the same thought, seem to be Paterson Photographic Film Clips, right?
https://patersonphotographic.com/product/paterson-film-clip-set/

I usually use wooden cloth picks, sometimes I worry the film could slip out but so far this never happened. the paterson ones seems much more secure and certainly the better option if hanging at a 45deg angle.

I should add that my wash procedure is simply tap water for the wash and a single bath of deionised water (no wash aid) for the last rinse for 2-3 minutes, then hang them vertically. this gives me very clean negatives with most films (mostly Kodak Tri-X and T-Max in 135 and 120). the only ones I can remember having troubles was with Agfa Copex in clear skies. It never made sense to me, since in pure water there should be no possibility for drying marks, so I kinda put it off as film defects. but reading the Kodak tech pub I guess it could well be a differential drying marks problem, so I'll change some things next time.

thanks for sharing all the details of your journey brian, it was an interesting read and it made me think.

Those are the ones.

 

[GLS]

the only ones I can remember having troubles was with Agfa Copex in clear skies. It never made sense to me, since in pure water there should be no possibility for drying marks, so I kinda put it off as film defects. but reading the Kodak tech pub I guess it could well be a differential drying marks problem, so I'll change some things next time.

I've developed quite a bit of Copex Rapid using the wash routine I outlined earlier in the thread. Never a single mark of any kind, despite the amount of IPA I use not being enough to completely avoid droplets. I also hang the film vertically.

 

[RoboRepublic]

Sorry, I edited my post after you replied to say they are dark which indeed may be instructive. See attached

Just curious if you have run any other process through the tank? (e6/ecn2/c41)

 

[John Louis]

Hi all, it's early days, but just hanging at an angle (all else being equal) has resulted in spotless negs so far with very sky heavy rolls - and end frames specifically.

To summarise my wash and dry process:
- Ilford wash with tap water, no soaking (to clear chems)
- Two extra Ilford washes with deionised water, 20 inversions and 3 minute soaks (to clear tap water, chems)
- Ilfotol 1:200 (one teaspoon at 5ml to 1 litre deionised water) in a jug, stirred well then drop film in while still on reel, soak for a minute or two
- Pull film out of reel slowly while still in the solution, check water sheets nicely with no bubbles
- Hang at around 45 degrees as shown in Brian's pics above (with those same Patterson clips which are great)

If I'm not back in touch, consider it solved.

Thanks for all the contributions, Brian and Maris particularly.

 

[Sirius Glass]

Hi all, it's early days, but just hanging at an angle (all else being equal) has resulted in spotless negs so far with very sky heavy rolls - and end frames specifically.

To summarise my wash and dry process:
- Ilford wash with tap water, no soaking (to clear chems)
- Two extra Ilford washes with deionised water, 20 inversions and 3 minute soaks (to clear tap water, chems)
- Ilfotol 1:200 (one teaspoon at 5ml to 1 litre deionised water) in a jug, stirred well then drop film in while still on reel, soak for a minute or two
- Pull film out of reel slowly while still in the solution, check water sheets nicely with no bubbles
- Hang at around 45 degrees as shown in Brian's pics above (with those same Patterson clips which are great)

If I'm not back in touch, consider it solved.

Thanks for all the contributions, Brian and Maris particularly.

Also once the film has been hung, take a paper towel and hold it to the lowest corner of the film to draw off the excess water.