My first tray development - Issues

[Chuck_P]

Take a vertically-oriented shot and if it’s uneven development the orientation of the streaks will change. It’s possible the issue is flare/ghost of the bright curtains and your development is fine.

It's hard for me to imagine that since I have several negatives with just as bright highlights, even one with a highlight-fall value of Zone XII+, developed in the SP445 with no issues like having here with unevenness. The Zone XII+ highlight on that negative was not tamed by BTTB the way I would've liked.

 

[Chuck_P]

Sorry, I don't follow the line of reasoning that goes from a single seemingly underdeveloped sheet of film to the conclusion that a 2-bath developer used in trays is the way to go.

In your quote below, your advice was to use a single bath developer....................that it should be able to perfectly replicate the results of a two-bath developer, maybe I misunderstood. But my example indicates, to me, that the two-bath development produced a better looking, more informative negative under the same exposure and scene contrast than the negative from the single-bath XTOL (EDIT: when I developed those negatives in the SP445 tank)............I wasn't referring to it being better in tray development, but that I got a better negative using BTTB versus XTOL single-bath. EDIT: The second part of the statement below seemed to be suggesting that a single-bath dev can replicate anything that a two-bath can do, hence my response in post #22, at least as it pertains to the high contrast scene in my living room. Sorry if I have I misunderstood your statement.

My recommendation at this point would be to use a normal single-step developer instead............................I personally also don't believe there's any magic to a two-bath developer that cannot be replicated perfectly well with a single-step developer.

 

[Paul Howell]

I do use Diafine with Foma 100 and 400 in both 2 1/4 X 3 1/4 and 4X5 for high contrast scenes, I use deep tanks and hangers, to date I have had any issues with uneven development, and I think Foma sheet film is a thin emulsion but not as thin as Tmax or Delta. Has anyone used Diafine with Tmax and Delta sheet film?

 

[Bill Burk]

It's hard for me to imagine that since I have several negatives with just as bright highlights, even one with a highlight-fall value of Zone XII+, developed in the SP445 with no issues like having here with unevenness. The Zone XII+ highlight on that negative was not tamed by BTTB the way I would've liked.

If they are internal reflections off the bellows, they will do the same on a vertical shot. But if they are uneven development, streaks will change direction.

 

[Chuck_P]

If they are internal reflections off the bellows, they will do the same on a vertical shot. But if they are uneven development, streaks will change direction.

So you saying that the problem area of the negative are potentially areas of added density due to possible internal reflections off the bellows. I'm saying that the problem area of the negative are areas of lesser density on the negative in the wall area. The tone of the wall in the photograph should be the tone that is the lighter tone, not the darker blotches on the wall.

 

[Chuck_P]

Another thought would be that handling multiple sheets in a tray could be asking for trouble. Emulsion could be marred more easily. Are sheet films thinner than what they were back in the 90s?

I don't know about the thickness of older sheet films, but no way will I mess with multiple sheets in a tray, there's all those horror stories out there on that.......gouges, scratches, what a headache.

 

[Paul Howell]

I tired trays once or twice, was taught the AA shuffle, never did get the hang of it, I only use deep tanks with hangers.

 

[Augustus Caesar]

It's a familiar image that I've been photographing regarding my use of BTTB but this time is with tray development. Naturally, I have an issue.

The particulars of the exposure: TMX at EI32, placement = ZIII (chair cushion), fall = ZX-ZXI (high values on curtain); developed in BTTB7 (7g s. metaborate in bath B); 4 min in bath A with continuous agitation following Kodak's instructions as seen in the J-1 publication; 4 min in bath B without agitation. Two sources that I have read: in The Negative and in a quote from BT that was posted in a different thread say that with this process, no agitation in bath B. Thornton's was more like.........no agitation is ideal. He spoke regarding preventing streamers from sprocket holes due to no agitation but alluded to it working well with unsprocketed film, which would include sheet film. AA suggested 3 min in the first solution but I used 4 minutes.

The first issue is the vertical thinner area on the wall behind the chair, this must be uneven development. You might be inclined to think that it's also uneven development on the far-right edge of the negative on the wall behind the chair where there's more density, but this is accurate. The second issue is that speck on the curtain; this is actually the film base. Perhaps something on the negative in the holder, but I take great pains to prevent that, anyway..........probably so, just wanted to point it out since it is my first effort at tray development. The bigger issue is the uneven development, and I don't understand it. My prior similar images using the SP445 tank were developed at 4.5min each bath and with intermittent agitation in both baths. Bath A: 5s/30s and bath B: 5s/60s.

The two sources I mention have two things in common: as stated, no agitation in bath B, and both are speaking relative to traditional grain film; why then, is this occurring? Could it be continuous agitation in the A bath, surely not? My first effort at BTTB using the tank, I also got uneven development without agitation in bath B, corrected when introducing the 5s/60s scheme in the B bath. I'll introduce the same or milder agitation to the tray in the B bath with the next sheet to compare.

I have stuck in my mind that agitation in the B bath does not maximize the capability of the two-solution process with regard to high contrast scenes, after all there's two fine sources that seem to indicate just that. But I think that T-grain film does not like it. This particular negative, apart from the uneven developed area, very well could be better than any of the previous 6 using the tank, therefore it's particularly frustrating.

Thanks @MattKing for the link to that blank screen, I never knew it existed, and it was perfect for this cell phone image of the negative. I used the film holder for my V700 scanner to hold the negative about 4 inches from the screen.


View attachment 391199

View attachment 391198

This cannot be a defect in the film or development. It must be something in the camera or on the wall.

 

[Harry Callahan]

If this was an internal problem of the camera or shadows on the wall, it should occur on the same area on different negatives - but the effect does vary.

One difference between tank and tray should be that you have to pour the developer into the tank - which should count as a form of agitation. If you put a sheet of film into a tray, there probably is less agitation to the film.
When pouring the developer out off the tank there also should be more agitation to the film as to taking the sheet out of the tray.
Also question is how much you agitate the tank in relation to the tray. If you invert the tank, you may be agitating the film more than by lifting the tray a bit.

You said that the uneven development did disappear when you added agitation to bath B using the tank. This indicates that more agitation does produce even development - and that there is too few agitation with the tray.

 

[koraks]

But my example indicates, to me, that the two-bath development produced a better looking, more informative negative under the same exposure and scene contrast than the negative from the single-bath XTOL

The problem is that you did ONE experiment which apparently failed for whatever reasons may have played a role (process control issues, inappropriate process parameter choice, chemical deterioration etc. etc.) That single experiment cannot be taken as a basis to conclude that by definition a two-bath developer is better.

What you're trying to do with the indoor scene you've shown so far can perfectly well be done with virtually every single-bath developer. It doesn't even require any N-2 etc.; just rate your film at box speed (which is perfectly fine for TMX) expose so you have detail in the shadows where you need it and process normally in whatever you fancy; D76, XTOL, Rodinal et. etc. and will come out just fine.

IDK what went wrong with your single XTOL-processed sheet and if in fact anything went wrong to begin with. All I've seen is a single scan which is dark for the XTOL scene, but that doesn't tell me anything about the negative in question. Maybe the negative is fine. Maybe the negative isn't fine, but your developer was old or somehow bad (it's XTOL so liable to dying quite suddenly; Fenton reaction), maybe you f-ed up the processing, maybe....

All I'm saying is that you seem to haphazardly jump to conclusions. I don't share that conclusion because I suspect that the experimental setup is fatally flawed.

I think Foma sheet film is a thin emulsion but not as thin as Tmax or Delta

The whole 'thin emulsion' thing is a gross simplification and not really relevant. What matters most is the degree of hardening of the emulsion and thus the volume of water it can absorb. If you take the exact same gelatin load per square meter and harden it at various degrees, you'll see that the degree to which it'll swell (absorb water/developer) will vary considerably. This is one of the key differences between Fomapan and Kodak films; the Fomapan films are generally hardened much less. How physically thick the layers are is not all that relevant; ultimately it's about how much volume of water they'll absorb. For the rate of absorption, it's furthermore relevant how hard the topcoat layer is and I suspect that in this regard there are very, very big differences between e.g. Kodak and Foma films.

I also suspect that the hardening of the top-coat in particular plays a big role in development evenness, with a very hard top-coat making it more difficult for processing liquids to diffuse through the emulsion. Tiny fluctuations in thickness of the layer stack and particular the top-coat can very well translate into greater risk of unevenness under marginal processing conditions. Such conditions are deliberately invited in a 2-bath development regime.

Overall, the most dependable approach to obtain perfectly even development is to ensure a steady rate of diffusion of active developer (and other processing liquids in subsequent steps) through the emulsion. This is very much like the age-old diatribe on stand development and dramatically reduced agitation schemes - yes, they sometimes work, and yes, they're also more prone to evenness problems, and yes, it's been demonstrated time and again that the boring, conservative approach of agitating every at least every minute or so works very well. So if there are problems with uneven development, the very obvious thing to try first is go back to that known-good state that we've known about for over a century, and get that to work. Then, if there's a compelling need, go back to more fancy experiments that are also more liable to give problems, and see if those can be sorted out.

 

[Chuck_P]

Of coarse my thread is about tray processing and uniformity of development and this sidebar discussion is entirely my fault. So, my apologies. I will give you the last word, below are my last words on it.

That single experiment cannot be taken as a basis to conclude that by definition a two-bath developer is better.

I'm only concluding that in this instance the N-2 development for XTOL produced an inferior negative to the one developed in BTTB. The exposure and contrast for each negative were identical. I don't know how to convince that the XTOL development (my processing) or the developer itself, or the exposures was not at any fault for producing what I consider to be an inferior negative. I am merely saying, in my opinion BTTB did a better job in that instance, and that's all I'm saying.

Nothing went wrong with the XTOL N-2 processed sheet. It's bit thinner negative across the board as is expected with any N-2 contracted development. Compared to the BTTB negative developed for even less time than the XTOL negative, the former simply was a superior result. Granted, it's just a single scan and I see your point and granted, there's different ways to skin a cat. The negative is fine, and I could print it, but it is not as fine as the other one, the developer was definitely not old, and I didn't F-up the processing. Like I said, I don't know how to convince.

All I'm saying is that you seem to haphazardly jump to conclusions. I don't share that conclusion because I suspect that the experimental setup is fatally flawed.

I'm telling you what I did and it couldn't have been a simpler set up. Meter, expose, make notes, flip the holder, verify the meter, expose again, make more notes, develop. You must feel the fatal flaw is in the "develop" part or the "expose" part or both, well, I've no way to prove myself to you on it. I can accept if you disagree with me, that's ok, I'm not getting fluffed up about any of it. If you knew me, you would never be able to accuse me of haphazardly concluding or doing anything. This is not saying that I can't have an incorrect conclusion, I accept that possibility, but I'm not seeing it............yet.

 

[Chuck_P]

If this was an internal problem of the camera or shadows on the wall, it should occur on the same area on different negatives - but the effect does vary.

Precisely.

It has varied with each tray-developed negative. The tonality of the wall should not have any irregularly shaped dark areas at all. From the right edge of the negative and from the edge of the curtain next to the wall, the tonality of the wall as it progresses toward the corner of the walls should gently fade to a lower reflected value and be at its lowest value at the corner. In setting up this little experiment, I did the best I could to make sure that each exposure was made around the same general time of the morning and catching roughly the same light intensity at the window (albeit on different days depending on the sky conditions), feeling that is important to my evaluations. All the low and high value EVs for these exposures confirms this. All this to say that the wall is not being affected by irregular shadowing or added density due to internal bellows reflections. I appreciate all those observations, but they are not the case, there are several negatives in these light conditions developed in the 445 tank that show absolutely none of these uneven areas of development. I grant that there's probably some beneficial flare on the negative helping out the shadows, I'll take it.

All your statements are in line with my own thoughts on the tray versus the tank development. Though the agitation at the film surface is entirely different, the other textured areas of the negative are nicely developed in the tray and I guess any unevenness just can't be detected. So, it certainly seems that the wave action type of agitation provided in the tray is just not adequate with TMX. But others have had uniformity issues with non-T-grain films too, so I guess the reality is that T-grain has no real bearing on it, as was postulated by Milpool in his post #13. I only use TMX so I have no other comparison.

I don't feel the need to post it but I completed the third tray developed sheet (still 4 min each bath) making very certain that I kept the emulsion side up in the transfer to the B bath. I gave no agitation in the B bath, just in case Doremus' observation settled the issue for me, and in that instance, I'd end up with a uniformly tray-developed, continuously agitated A-bath negative without B any bath agitation. But to no avail...........the uniformity is still present, but not as bad as seen in my post #12. Was it due to insufficient tray agitation in bath A or no B bath agitation, there has been unevenness with bath B agitation...........Idk, it's confounding.

I have one more negative, but it will be developed for comparison purposes against the tray developed negatives in the SP445 tank. It will be given 5sec/30sec agitation in bath A, and I will give no agitation in bath B, still giving that idea of no bath B agitation concept a try. I'll see what happens.

 

[koraks]

This is not saying that I can't have an incorrect conclusion, I accept that possibility, but I'm not seeing it............yet.

The conclusion you draw is on the basis of one sheet that didn't come out to your liking. I don't see how that justifies the conclusion that two-bath development is the way forward for you. It just shows that the one other sheet you did with BTTB came out better - but now you're dealing with uneven development issues. I think (know) that the latter is far more easy to fix with a single-step developer, and that you can make a single-developer process work just fine for whatever purpose you have in mind.

Did you try extending the XTOL time to get a denser negative? If not, how can you conclude that the BTTB approach was inherently better, and that the difference wasn't just due to an unfortunate choice in process parameter selection?

 

[retina_restoration]

A few remarks that may or may not be relevant to your situation.
I always develop sheet film in trays, one sheet at a time (unless it's just a technical test). I no longer use those Paterson style trays with the deep groves in the bottom, because I saw evidence that the design contributed to problems related to currents generated in the tray. Now, I only use Yankee type trays with shallow ribs on the bottom to keep film barely lifted off the bottom of the tray. (There are also flat bottomed trays by Cescolite, but you'd have to presoak film before using one of those trays for developer, or there's significant potential for the film to stick to the bottom)

I use Thornton 2-Bath often with sheet films and I have never had any kind of uneven development like what Chuck is seeing. I am skeptical that BTTB alone is responsible for the defects he got. In Bath A I agitate much like I would for any other developer: 30 seconds continuous at first and 5 seconds every 30 seconds. I am not gentle when agitating film in trays - I tip the tray alternating between left/right to top/bottom, and it's with enough force that I am at risk of sloshing developer out of the tray. Perhaps Chuck needs to try again and be more aggressive with agitation.
I do agitate through Bath B. I believe you do risk uneven development if you don't (with sheet film). I agitate for the first ten seconds, and then two rocks of the tray every 30 seconds. The only real (perceived) benefit of zero agitation in Bath B is a bit more edge effect to create acutance. I bet the difference in acutance is very, VERY minor, so you're potentially creating more problems than you solve if you opt for no agitation in B. That's just what my experience tells me, anyway, FWIW.

Question: how much film have you run through your A and B developer between refreshes? I tend to err on the side of caution with this developer, rarely processing more than 5 rolls of 120 or 5 sheets of 8x10 before dumping the chemistry and starting fresh. BTTB is so cheap to make that you can easily make fresh often, to avoid any problems with exhaustion or developer carryover. (Bath B accumulates Metol/sulfite and becomes more and more active)

I feel quite certain that Chuck's unevenness problem is entirely a technique issue. Maybe it's 2 or more issues compounding (wrong tray type + insufficient agitation?). I would do more tests and work to eliminate the potential contributors. I definitely feel that a divided developer has something to offer the photographer in certain situations (Like when some compression of the value scale is needed, but without losing value separation in parts of the curve) but there is some potential to get poor results without finessing the technique to fit your work habits. I firmly believe that the problem can be resolved once the responsible factor(s) is eliminated. I find Thornton 2-Bath to be a very useful tool in my darkroom vocabulary, and for me, it's been mostly trouble free and effortless, and the results well worth it.

 

[Chuck_P]

Did you try extending the XTOL time to get a denser negative? If not, how can you conclude that the BTTB approach was inherently better, and that the difference wasn't just due to an unfortunate choice in process parameter selection?

Ok, I'm not keeping my previous word as being the last, but you ask a good question. I ask that then, that if anyone is inclined to hammer the perceived flaws of the ZS fixed density method of speed determination, to kindly not. This is how I do it.

Since this sidebar topic is comparing the merits of XTOL vs. BTTB, I have to go back to my curve family I generated with BTTB to start with. In that curve family a development time of 4.5 min produced a curve that was on a trajectory, after adjusting it for a speed loss, to reach a N-2 contraction. I checked the densities of that curve at Zones I 1/2 , II, III, and IV. I then bounced those densities against the same curve densities at I 1/2, II, III, and IV of the N-2 development (5m 15sec) in single bath XTOL 1+0. At each zone, the BTTB N-2 density was a bit greater, not by a lot, but it was greater, than each of those same XTOL N-2 densities. I thought that was a positive outcome relative to the purpose behind two-bath development.

Fast forward to my experimenting with BTTB pictorial negatives with high contrast SBR. I have a pictorial comparison of tank developed XTOL 1+0 at N-2 versus a pictorial comparison of tank developed BTTB at N-2. The agitation scheme for XTOL: 5sec / 30sec. The agitation scheme for BTTB: A= 5sec / 30sec B= 5sec / 60sec.

So, the shadow placement I gave and where the important high value fell dictated contracted N-2 development for both negatives. I reason, what a fine time to compare XTOL N-2 with BTTB N-2. This is simply a comparison of one developer at N-2 vs. a different developer at N-2 of the exact same scene contrast and exact same shadow placement for each.....................and with that comparison, I'm putting the BTTB negative in the enlarger instead of the XTOL negative. If theirs's one caveat, it would be that the BTTB N-2 curve used 12g of s.m. in the B bath..........but at the time of doing the curve family I don't think I was much aware of the 7g of s.m. in bath B that supposedly helps with high contrast scenes. Perhaps that has made the bigger difference in the BTTB pictorial negative in my little experiment, but I really don't know. All I know is, it's plain to see which negative gets the enlarger time between those two efforts.

Naturally, I could've tried my XTOL N-1, or N curve but that's not doing the most important high value any good, the way I see it.

I do not know what more to say about it if this is not sufficient for you. But I appreciate all your contribution for sure.

 

[retina_restoration]

Naturally, I could've tried my XTOL N-1, or N curve but that's not doing the most important high value any good, the way I see it.

I do not know what more to say about it if this is not sufficient for you. But I appreciate all your contribution for sure.

Fact is, you can ask any 20 B&W photographers (or 200, for that matter) which developer + technique gives the best negatives, and every one of them will have a different opinion and process. What fails to be factored in is what each person wants their images to look like, and this is a huge factor in determining what technical choices that person makes. Some people are adamant that Xtol produces the best negatives possible. Others say it's Pyrocat HD, and yet others will swear that nothing could ever exceed the performance of D-76 1:1 and they are all right - for their needs.

There's little point in telling someone "that developer/technique won't get you there" when it's nearly impossible to define precisely where "there" is without standing next to that person and seeing what they're doing, and figuring out why it's not working.

 

[koraks]

I do not know what more to say about it if this is not sufficient for you.

It's OK for me; I think having read your explanation that the root cause of the difference you've seen is the development time determination that preceded it. If you had truly obtained comparable N-2 times for both developers, then the negatives would have come out very much the same. Apparently, this is not the case, so I'd look at the start of the process. Very simply put, it seems that the gamma you're getting with your selected XTOL time lags behind to that you've obtained with your BTTB time. At least in part, you also indicate having noticed this:

At each zone, the BTTB N-2 density was a bit greater, not by a lot, but it was greater, than each of those same XTOL N-2 densities.

...perhaps the significance of these slight differences may have turned out to be bigger than you had anticipated. Perhaps, referring also to what @retina_restoration says above, your preference happens to be with the beefier negative that BTTB has given you even though the other negative is just as 'technically correct', so to speak.

I'm thinking along those lines - but we're getting way off track in trying to solve the uneven development problem now, so maybe let's leave this tangent for now. Sorry to have brought it up; I guess my point can briefly be summarized as "before trying to solve the problem, see if it's necessary to encounter it in the first place."

 

[Chuck_P]

..................your preference happens to be with the beefier negative that BTTB has given you even though the other negative is just as 'technically correct', so to speak.

I think this is a fair summation, so yes, we can end this side discussion, thanks.

 

[Chuck_P]

Well, here's the final negative but it is developed in the 445 tank but without bath B agitation, I wanted to give that another shot with the tank. There's still some uniformity issues in the wall area imo, but really not that bad. I brought the wall value down in post just to see how well it might be hidden so to speak. I think I am resigned to stay primarily with the tank development in general and especially with any bath B agitation since my earlier negatives in the tank have no uniformity issues at the wall area. Perhaps I might develop some negatives in the tray where there is no real risk of actually seeing where uniformity issues are going to be most obvious. Even though the agitation of tray vs. the tank, to me, is entirely different at the surface of the film, the tray negatives, where there will be adequate texture were also very nicely developed.

I've no problem continuing with experimenting with tray development of this scene, but I wouldn't know how to proceed differently to justify another negative or two with any decent hopes of success. I'm open to other suggestions but it's probably the case that if there was a better way in tray, it would be known. Someone remarked, I think, that multiple sheet development in a tray actually provides much better continuous agitation to the sheets. But I won't be traveling that road for sure, I don't need that amount of frustration, just handling one sheet was slippery as it could be and felt so clumsy.

 

[koraks]

Looks better, but I recognize you still have some uneven development going on. On scenes with open skies this may become a problem at some point.

I remember troubleshooting unevenness issues with x-ray film in trays. X-ray film is exceedingly prone to unevenness, so that was a bit of a torture test. I figured out an agitation pattern that would give me virtually perfect evenness every time; it was continuous, relied on a tray a little larger than the print (but not a 'full size' larger as often recommended, although that would also work), and lifting & dropping opposing corners of the tray while at the same time watching the flow patterns on the developer surface (x-ray film is insensitive to red, so I could see what I was doing). If I kept the motion of the developer constantly moving, but gently so, I could skirt between the Scylla and Charybdis or excess edge density (too much agitation) and mottling (too little agitation; the problem you seem to be having).

I only did very brief experiments with two bath pyrocat with x-ray film so I can't help on you that; the only thing I do know is that in those experiments, development was not perfectly even. It took me a while to figure out the pattern referred to above that did work for me - but with a regular one-bath developer.

 

[Milpool]

It’s the type of agitation given by the shuffling method which produces better uniformity than tray rocking. There is no requirement that there be more than one sheet at a time.

Well, here's the final negative but it is developed in the 445 tank but without bath B agitation, I wanted to give that another shot with the tank. There's still some uniformity issues in the wall area imo, but really not that bad. I brought the wall value down in post just to see how well it might be hidden so to speak. I think I am resigned to stay primarily with the tank development in general and especially with any bath B agitation since my earlier negatives in the tank have no uniformity issues at the wall area. Perhaps I might develop some negatives in the tray where there is no real risk of actually seeing where uniformity issues are going to be most obvious. Even though the agitation of tray vs. the tank, to me, is entirely different at the surface of the film, the tray negatives, where there will be adequate texture were also very nicely developed.

I've no problem continuing with experimenting with tray development of this scene, but I wouldn't know how to proceed differently to justify another negative or two with any decent hopes of success. I'm open to other suggestions but it's probably the case that if there was a better way in tray, it would be known. Someone remarked, I think, that multiple sheet development in a tray actually provides much better continuous agitation to the sheets. But I won't be traveling that road for sure, I don't need that amount of frustration, just handling one sheet was slippery as it could be and felt so clumsy.

View attachment 391546 View attachment 391547

 

[Chuck_P]

.......... it was continuous, relied on a tray a little larger than the print (but not a 'full size' larger as often recommended, although that would also work), and lifting & dropping opposing corners of the tray while at the same time watching the flow patterns on the developer surface (x-ray film is insensitive to red, so I could see what I was doing). If I kept the motion of the developer constantly moving, but gently so, I could skirt between the Scylla and Charybdis or excess edge density (too much agitation) and mottling (too little agitation; the problem you seem to be having).

Sounds like such a tedious undertaking when not able to see the tray. If I try this again, it just feels like I need to be more vigorous with the tray (maybe use an 8x10 tray? Less spillage) in the A bath or even if using just single bath developing. Then I guess there's the danger of too much agitation with edge density that you mention. And honestly, until you said that I didn't realize there was such a thing as an edge density issue with tray development, that might be the proverbial last straw on the camels back.

There is no requirement that there be more than one sheet at a time.

Stating the obvious I guess...........it must be that you have to get that wave action type of agitation JUST EXACTLY RIGHT for this not to occur. I see why so many no longer do it, are there any that still do, I wonder.

 

[Milpool]

Stating the obvious I guess...........it must be that you have to get that wave action type of agitation JUST EXACTLY RIGHT for this not to occur. I see why so many no longer do it, are there any that still do, I wonder.

Mark Citret, for one. Without too much fuss the agitation given by the “shuffling” action (interleaving is probably a better word - in any case it can be done with one sheet or multiple sheets though multiple sheets introduces the risk of mechanical damage) seems to produce fairly good uniformity, and better than manipulation of the tray.

 

[koraks]

Sounds like such a tedious undertaking when not able to see the tray. If I try this again, it just feels like I need to be more vigorous with the tray (maybe use an 8x10 tray? Less spillage) in the A bath or even if using just single bath developing. Then I guess there's the danger of too much agitation with edge density that you mention. And honestly, until you said that I didn't realize there was such a thing as an edge density issue with tray development, that might be the proverbial straw on the camels back.

The good news is that the kind of film you're working with is far less susceptible to uneven development than the x-ray film I referred to. I mentioned that because it's a bit of an extreme example. With normal photographic film, problems tend to be much less severe; I routine tray-process 4x5" and 8x10" Fomapan film and in terms of agitation, I'm frankly winging it for the most part. I generally rock the tray a couple of times every 30 seconds and doze off the rest of the time. I've not had any uneven development processes with this approach, but my experience is limited to single-bath developers.

 

[Doremus Scudder]

I second the motion to agitate as in the shuffling method. I've found tray rocking to be inadequate. If you just have one sheet, lift it from the developer, rotate it and resubmerge at regular intervals. Be careful not to push the film down into the developer quickly, as this causes developer to surge at the edges giving you hot edges.

Doremus