View Full Version : Single sheet tray processing (8x10") with PMK

Tim V
8-Jul-2018, 04:26
Hi all,

Sorry for yet another tray processing thread, but I have a specific question regarding tray processing single sheets of 8x10" film (at this stage Bergger Pancro 400) in PMK.

As background, I've only ever tray developed a couple of times– using D76 only to test my technique–and at the advise of friends I did four sheets at once. My technique was not up to much as there were quite a few scratches on the emulsion. Streaking / banding wasn't so bad, but there weren't really any flat areas of tone to test that side of things properly. I constantly agitated by lifting bottom one out of soup, rotating 180 degrees, and putting it on top of stack. I patted the film down gently with my fingertips to make sure it was submerged, then lifted the next one out from bottom to do the same.

I want to process one sheet at a time because the type of work I'm making is very slow going, and I want to make sure each step of the process is very consistent as well as offering minimal risk of scratching, etc. I want to use PMK because it pairs well with the Bergger Pancro 400 by all accounts, plus I like what I see from examples of other film processed in this developer.

As with most people asking about tray developing, my question really is about or at least boils down to being about agitation.

Am I correct in thinking that after a 3min pre-soak, I should slip the sheet of film into the PMK emulsion side up, gently padding it down with my fingers. Following that, the great debate seems whether or not to continuously but gently rock each corner / side of the tray to agitate–working way around each side of the tray as to alternate the direction / motion of the waves–or to follow the same regime as I did with multiple sheets; that is to lift film out of the developer, rotate 180 degrees and place back in the developer patting down with finger tips for the duration of the development cycle.

I have read so much conflicting information about single sheet tray processing, with some agitating as either way described above; others following essentially a cycle akin to tank processing, with agitation once every min for ten seconds; and others stand processing, etc. Some even warn against it altogether because of streaking. I guess it must boil down to personal preference based on experience and adapting to idiosyncratic workflow choices. As I'm a novice at tray processing let alone using PMK, I thought it best to ask for some clear advise and warnings etc if I'm doing single sheets, listen and take note, then simply get stuck in. My only hope is that I minimise the mistakes, so I can simply get on with making the pictures and being able to predict how the processed negatives will turn out.



8-Jul-2018, 05:55
Why not Brush Development? Single sheet processing is easy and doing it this way gets clean negatives.

Submerge in the developer, emulsion side up. Then gently brush side to side, then up and down. Then again going from the opposite direction as the first. You go back and forth, not all in one direction. Don't get in a hurry and no downward pressure. Gently, quietly and repeatable. Clean sky areas without density differences. Learned from my Uncle - who learned from Jorge Gasteazoro who used to be on these forums and apparently was quite a character. The development using a brush does get good results

You are already in the dark doing one negative at a time. Why not try it? Nice Hake or Richeson magic brush works well.

Jim Noel
8-Jul-2018, 10:00
1st use an 11x14 tray for 8x10
2nd - My preferred method of agitation which I have used for 75+ years is to lift each corner in sequence every 30 seconds. I lift about 1-1.5 inches.

Doremus Scudder
8-Jul-2018, 12:15
I shuffle stacks of film in trays. When developing one sheet, I try to replicate my agitation scheme (once through the stack every 30 seconds). After an initial 30 seconds of continuous agitation by lifting and rotating the sheet, I lift, rotate and resubmerge the sheet once every 15 seconds. I believe this best approximates the amount of agitation a sheet would get when shuffling in batches, since there is agitation when you lift the sheet out and resubmerge it and agitation when you place the subsequent sheet on top of it. BTW, this is with PMK and 4x5 film.

As for evenness of development: not creating turbulence, areas of more/less agitation or standing waves in the tray is key. Using a larger tray than your negative is indispensable here. Also important is not pushing the negative down too quickly (causes turbulence and more agitation at the edges) and neglecting to swish your fingertips around the middle of the negative (to keep this area from getting too little agitation). This with shuffle-agitation. With tray rocking (not my preferred method), the challenge is to not set up standing waves. Being random rather than regular and making sure your agitations are vigorous enough seems to the the key here.

Batch developing with 8x10 negatives is something I have never done, but my experience with smaller negs is that practice and care (and a modicum of dexterity) are needed to avoid scratches. Maybe some 8x10 tray developers will chime in here with their methods.



Tim V
8-Jul-2018, 14:17
Thanks all, I appreciate people taking the time to reply with such a novice question...

I've been shooting large format for over a decade, but almost never black and white. I'm enjoying being back in the darkroom!

Brush development sounds interesting. I'll certainly give that some more research and give it a go.

In the meantime, I guess it's mostly about simply trying and learning. I'm still a bit torn between methods, i.e. emulating the shuffle method with one sheet or lifting alternate corners of the tray. For some reason the latter seems a bit easier, but I can imagine this method needs really careful technique to avoid standing waves, etc.

Anyway, any other tips on using PMK / Pyro developer? I know gloves are a must, but anything else?

Thanks again,


Drew Wiley
9-Jul-2018, 17:11
I shuffle only three or four 8x10 sheets at a time every 30 sec, emulsion up in 1 liter volume of pyro, being very careful to prevent a corner of any sheet from
contacting and scratching another sheet. The tray is oversized, about 11x14, with a dimpled bottom. On those rare occasion when I do only one sheet, I gently rock it, slightly lifting up a different corner about every 10 sec. Practice and consistency are the clues; and for me at at least, not being tired and stupid when I do it. If I'm just plain worn out that day, it can wait.

Gary Samson
9-Jul-2018, 18:50

Do you have the book on PMK Pyro by Gordon Hutchins? Mr. Hutchings has a specific procedure for processing single negatives in a tray with PMK Pyro that works very well. If you are serious about using this developer I would highly recommend getting the book, there is a great deal of helpful info in the publication.

Drew Wiley
9-Jul-2018, 18:55
There's nothing different developing PMK from ordinary developers like HC110 or D76. I use exactly the same rotational cycles. Only the overall time potentially is different.

11-Jul-2018, 06:32
I have not tried the brush method on normal panchromatic films yet, only on 8X10 Xray film. A soft 5" wide hake brush left very faint marks (scratches) in the emulsion of the Xray film - I am guessing due to the extremely soft nature of the emulsion. I have no idea if this would happen to normal panchromatic films if the brush comes in contact with the emulsion.

12-Jul-2018, 00:28
X-ray film seems to lack a superhardened topcoat, which makes it extremely vulnerable. Regular films do have this topcoat, but its hardness varies. It seems to me that e.g. Foma/Arista.edu films have a somewhat softer topcoat than Kodak films, which may influence the risk of damage with brush development.

Tim V
12-Jul-2018, 03:19
Thanks again, all.

Yes, I do have the Gordon Hutchins PMK, bought via Photographer's Formulary. I have a sense that the film I'm currently using, being Bergger Pancro 400, has a soft emulsion but this is only a vaguely informed guess on my part. Does anyone know where it is actually made? By Ilford, perhaps? I actually really want to shoot the Adox CHS 100 II for its look, but for the life of me can't find any in sheets.

Anyway, back to tray processing. My good friends who are very much masters of this stuff keep restating to me that tray processing single sheets is very problematic, siting turbulence at the edges of the sheet that create streaking / areas of higher density. I'm not sure how this could be any worse than with multiple sheets, and maybe I'm wilfully ignorant at best and belligerent at worst, but I'm convinced I can master it. If nothing else, at least doing one sheet at a time will lessen the likelihood of scratching the film. Anyway, part of the reason for going 8x10" from shooting 4x5" and MF digital on Linhof platforms is that I want to slow things down and concentrate on all aspects of the craft again. I'm not experienced with pyro developers and tray processing at all, but I've been shooting view cameras exclusively for a long time now and have been looking forward to experimenting for myself how different film / dev combinations etc might help lead to new territory for my work. I have some specific things I want to try for conceptual reasons, like ultra-long exposures of an area I've been photographing consistently for years, and I like the idea that the pyro might help compress the highlights of an image and help with printing.

I'm still intrigued with this brush processing technique, too. Must do more reading about it...

12-Jul-2018, 05:48
"...tray processing single sheets is very problematic, siting turbulence at the edges of the sheet that create streaking / areas of higher density."

I agree that this could be a problem, but as some have pointed out, if you use a larger tray, that should minimize that problem. I think the turbulence is worst near the tray wall, so if your sheet of film is farther away from the tray walls, there will be less turbulence.
I guess an experiment should be done by shooting two identical 4X5 exposures of a scene, then processing one sheet in a 5X7 tray, then the same image in an 8X10 tray with the same agitation method, and compare the edge densities.

For what it's worth, I have process as many as 18 4X5 sheets at a time in 8X10 trays, gotten what I would consider even development and minimal scratching...what I would consider.

Drew Wiley
12-Jul-2018, 15:09
18 ?? That sure beats my record of 12 4X5's. Usually I just do six or so. Edge surge issues depend on your style of agitation, the size of the tray (hopefully
it's oversized), the solution volume (more is better), the specific developer, and yes, even on the type of sheet film itself. Thicker emulsions seem much more
affected than modern thin emulsions. It makes sense, since they absorb and retain more solution. I don't think any true thick emulsion films are still on the market, but products like HP5, and to some extent even FP4, exhibit much more added perimeter fbf than TMax sheet films, whose edges come out completely clear of fog, at least for me. All the EU films I've tested had significant edge density increase - something to factor in when composing in the groundglass to begin with; you want a little extra margin around the ideal composition.

Dan Dozer
9-Aug-2018, 21:04
Hi Tim,

I exclusively tray process single sheets of 8 x 10 in PMK, and have done it this way for many years. I have found that it is the most fool proof method for me to eliminate scratches in the negatives. As a couple of others have said, it is crucial that you process your film in trays that are one size larger than the film, so for 8 x 10 film, use 11 x 14 trays. Otherwise, you will get uneven developing around the edges.

My process - I don't pre-soak my film. It goes directly from the film holders to the developing trays and I do two sheets at a time (two trays with one sheet in each tray). First and foremost - wear gloves in the process. Hold the film from the top and slide the film into the trays from the top toward the bottom and the film will evenly go towards the bottom of the trays. You won't have to push the film down with your fingers. As soon as the film is in the trays, agitate each side of the trays for about 5 seconds and then go the next side. Don't be shy about sloshing the developer in your agitation process. After 30 seconds of continuous agitation, you will have agitated from all four sides of the trays. Then let the trays sit. Then agitate the trays 2 - 3 times every 15 seconds and each time switch to a different side of the trays. I make it easy on myself and the side of the trays I agitate is the same as the direction of the second hand on my timer. Continue this all through the developing time and then transfer to the wash water tray. Note that after the developing, I continue the process with two negatives in a single tray for the rest of the chemicals and then carefully rotate the negs top to bottom. This process is pretty much what Gordon Hutchings says to do in his book and it has worked very well for me.

Hope this helps.