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Rotary processing and surge marks/bromide drag?


I have been finger squeegeeing for years and largely I follow the Ilford method with the addition of the first 30 secs being continuous

I wonder, can we classify the above as the "British way is best?" No, on second thoughts just ignore that line. The best way is the one that works

Seriously I hope this is a permanent cure and not just another false dawn

pentaxuser
 

Thanks. I'm probably going to up the agitation frequency to 4 inversions every 30s rather than every minute just to see how that goes. As @Don Heisz suggested way back at the beginning of this thread, the relatively high dilutions of HC-110 and Rodinal that I've been using may require more frequent agitation to avoid this issue.

I'm just happy to see a few rolls without the streaking that I've been experiencing for so long. Hopefully I can keep that at bay while I work to eliminate this last issue.
 

I'm sure the Ilford method is effective for many people, but I may need additional agitation since I'm using fairly high dilutions. At some point I might start to back off on the dilution of HC-110, but I'm sticking with dilution H for now to keep the number of variables to a minimum.

Finger-squeegeeing seems to be working for me to eliminate streaking. I might be able to increase the dilution of the Photoflo mixture so that squeegeeing isn't required, but I'm not going to rock the boat at this point
 
HC-110 is a high energy developer, I wonder if that is part of the problem? I'd be inclined to get a litre package of Perceptol and develop as you used to and see if there are any marks.
 

Great, you have improvement. So added agitation has eliminated most of the problem.
 

I've read a few times recently, in the context of extreme minimal agitation/ semi-stand, that it's vital in order to avoid unevenness that the initial agitation must be thorough, often recommended at least 2min continuous inversion. I know that the OP isn't into EMA, but I mention it as it does seem that the beginning of development is critical.
 

When the manufacturers have spend millions of dollars on R&D and recommend agitation patterns, why would anyone with much less experience think that they are better experts and will get better results with stand or semi-stand development? Why not experiment unrolling an exposed film to direct sunlight to make sure that two electrons have been captured by every grain of emulsion?
 

That was not my point. But thanks for reminding us that since companies like Kodak have stopped research into black and white films, there will not ever be any new knowledge.
 
That was not my point. But thanks for reminding us that since companies like Kodak have stopped research into black and white films, there will not ever be any new knowledge.

Eastman Kodak still has an R & D department - in fact if Covid 19 hadn't happened I think you would have seen further re-introductions of some older film products, using the currently available constituents and manufacturing, and incorporating some nice improvements..
The R &D department is far smaller than in the past, and financially constrained, but it was that department that was integral in dealing with the wrapper offset debacle.
 
That was not my point. But thanks for reminding us that since companies like Kodak have stopped research into black and white films, there will not ever be any new knowledge.

Please site your information about the R&D at Kodak. Aside from the fact that the past research showed that my statements are time invariant.
 
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Thank you for pointing out that Kodak are still doing R&D. I stand corrected. The ups and downs, mostly downs, of the last couple of years led me to think that they had lost the plot. And maybe some new products?
 
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It may very well be correct that, relatively speaking, very little of the R&D money at Eastman Kodak is going to B&W still film. Colour and motion picture film (which includes black and white) probably gets more.
And of course, Eastman Kodak's main business isn't its photographic business, so its R&D dollars are spent on non-photographic things too!
 
@logan2z have you figured this out? I'm having an issue that manifests identically to what you were having here.

I'm using Ilfotec HC (HC-110) dilution H, HP5+ in 35mm, inversion agitation in a Patterson 2-reel tank.
 
@logan2z have you figured this out? I'm having an issue that manifests identically to what you were having here.

I'm using Ilfotec HC (HC-110) dilution H, HP5+ in 35mm, inversion agitation in a Patterson 2-reel tank.

I narrowed the problem down to my use of Photoflo during the final rinse. I stopped using Photoflo and switched to LFN instead. I also introduced a 5 minute soak in distilled water before the final rinse (as recommended in an old thread by @Doremus Scudder) and then started using Kimwipes to gently wipe both sides of the film after hanging to dry. After these modifications to my workflow, the problem never recurred.
 
Thanks! I'm using Adox Adoflo II at the moment, will give this a try
 
@logan2z have you figured this out? I'm having an issue that manifests identically to what you were having here.

I'm using Ilfotec HC (HC-110) dilution H, HP5+ in 35mm, inversion agitation in a Patterson 2-reel tank.

You could always try a more gentler way of agitating. I've always found inversion to be too aggressive with 35mm. I've been using the figure 8 method since I started teaching high school level photography. In fact, I insist that all my students do it this way. We also use HP5, and skip a pre-wash step (Ilford recommends against it, but I do it for my personal work, depending on the developer, like FX-55 for example... ) and we only ever use a surfactant like Photo-flo after the final wash (which has nothing to do with the issue of bromide drag/streaks btw).