4x5, PMK problems...

[amilne]

I've been using PMK for a few years now with roll film. I'm now trying to use it with LF, and am having some problems. I have searched, and found a few posts relating to this exact topic. I used the suggestions found there as well as in Gordon Hutchings' book. Emulsion down, 1 cycle per 15 seconds. I'm using HP5 @ 13 min for normal, @ 70F.

I processed one fogged negative, and one real negative, the results are attached. The real negative looks fine, the fogged one... well, see for yourself. The real negative is complicated, so the flaws probably aren't visible, but I wouldn't want to process a negative with empty skies or anything with these results.

Any suggestions? I've tried this twice with the same results.
Thanks-
-Alex

[David A. Goldfarb]

Increased density at the edges is usually from using too small a tray. If you are using 4x5" trays, move up to 5x7" or 8x10", and be sure you have enough solution in the tray so the sheets move easily.

When tray developing I develop emulsion side up, and I divide the developing time into four periods and rotate the stack at each quarter. I also find that I get better results with two or more sheets than with one sheet, but don't do more sheets than you're comfortable with. Start with 2-4, and work your way up from there. Unless you are doing brush development (do a search to see what that's all about, if you're not familiar with it), I find that developing one sheet in a tray and rocking the tray will exaggerate the effect of increased agitation from the sides of the tray.

[steve simmons]

Try the procedure I outlined in an article in the Free Articles section of the View Camera web site. It has worked for me for 26+ years.

www.viewcamera.com

steve simmons

[Doremus Scudder]

I assume that the fogged neg is included to show the uneven development. Part of that may be with the way the negative was fogged/exposed as well (camera lenses have fall-off; even enlarger light is notoriously uneven....) However, let's assume it was exposed evenly and that the problem is in the developing step.

PMK can be tricky when it comes to agitation. It has a tendency to streak and mottle if you are not careful. So, try different agitation schemes. If the development is uneven, the agitation is usually not consistent enough. Steve Simmons method works well. I use less agitation: once through the stack every 30 seconds for the first half of development, once every minute thereafter.

The initial immersion in the developer is critical. Presoak your negs for 1-2 minutes before immersing them in the developer. This will promote more even diffusion of the developer into the emulsion. I also introduce each negative to the developer separately, giving it about 5 seconds of agitation alone before adding another. This is compensated for when transferring the negs to the stop, which is done in the same order and at the same time interval to ensure that the dev. time remains the same.

Part of your problem seems to be too-dense edges. The following may help:

Don't over-agitate the sheets by moving them up-and-down in the developer a lot. This can cause over-development on the edges. Instead, lift the neg out of the solution, let it drain just a little, then immerse it again, pushing it down slowly with the balls of your fingers. Too fast, and the edges get a lot of developer rushing by, i.e. more agitation than the center. More frequent but less vigourous agitation is usually the cure for this kind of unevenness.

Keep trying till you get it right. PMK is lovely stuff once you get the hang of it.

BTW, use gloves!

Good luck,

Doremus Scudder

[Mark Sampson]

I've found that the presoak is essential; however, rather than using plain water, I use a dilute (1&#37 Kodalk solution. This keeps the sheets from wanting to stick together, and I believe (but have not tested to prove) that this promotes even development as well. That may be in Mr. Hutchings' book; I started using Kodalk at least ten years back but don't remember where I learned it.

[amilne]

Thanks for all the replies.

If it helps, I am using an 8X10 tray, I also have 2 minutes presoak (without the alkali solution), and steve, yuor article was the one I found in my first search, it was quite helpful.

Maybe all this will take is practice and trail and error, although, or course, I wouldn't be totally opposed to speeding up the process.
-Alex

[Brian Ellis]

If you get tired of standing over trays in the dark while inhaling chemical fumes you might look at the BTZS tubes. www.theviewcamerastore.com. I've used them for many years and much prefer them to the tray developing I used to do with 8x10 and PMK. With the tubes I've never had a problem with uneven development, never had a scratch, use only 2 ounces of chemistry per sheet, do everything in daylight once the tubes are loaded.

[zoneVIII]

If you get tired of standing over trays in the dark while inhaling chemical fumes you might look at the BTZS tubes. www.theviewcamerastore.com. I've used them for many years and much prefer them to the tray developing I used to do with 8x10 and PMK. With the tubes I've never had a problem with uneven development, never had a scratch, use only 2 ounces of chemistry per sheet, do everything in daylight once the tubes are loaded.

I make my own tubes from PVC for 4x5, it's give me excellent result, minimize scratcht and uneven development on my negs, with standing dev, when i want to agitate it, just rolling the tube for the time agitate

[steve simmons]

Anytime you work in the darkroom you need proper ventilation. That will take care of any noxious smells. Trays work fine. PMK is a very inexpensive develope to use.

steve simmons

[Ken Lee]

You might find it advantageous to use deeper and cheaper trays: the widely available plastic storage bins that we find at discount stores.

If to that, you add the use of an infra-red viewing device, you will find that you get fewer scratches and more even agitation. Because you can see exactly what you are doing, you can also perform Development by Inspection. Not in the tradtional manner, where you take a brief peek under a dim safelight, but the entire process, from taking the film out of the holders, to fixing and beyond.

For what it's worth, I just tray-developed 10 5x7 and 8 4x5 negatives -together - at the same time. Using this combination of equipment, it was no big deal.