Hi, I am having a problem with my pmk negatives, I have read and am following Gordon Hutchings procedure for processing 4x5 sheet film in trays. I shoot fp4 and process for 10 min. at 70 deg. I mix the pmk prior to development and bring up to temp in a jobo temp bath in 1 liter bottles. I am getting small dark spots on my negs. otherwise they look great. I use only distilled water, I have tried a presoak with no luck. I process one sheet at a time. I have repaced my trays and bottles with no help. Thanks for any help. Bill Bartels ( P.S. I use tf4 fixer)

-- Bill Bartels (tlr220@msn.com), December 28, 1999

Answers

Just guessing.... Do you use acid stop bath? PMK is quite alcaline and strong stop bath can give rise to unwanted reactions in the emulsion. Try very dilute stop bath or preferably rinse with pure water first.

Sakari

-- Sakari Makela (sakari.makela@koulut.vantaa.fi), December 29, 1999.

I saw this post but I didn't want to say anything becuase I've never experienced exactly what you say is the problem you're having. However the above poster is right, I have had problems with pinholing etc., with PMK, but as soon as I got rid of stop bath altogether (I just use water with continuous agitation for 1-1/2 minutes), my negatives have been fine.

Try a water only stop bath and see what happens. I've also tried to take it to the n-th degree by using a fixer that doesn't contain any acetic acid, too (Kodak F24); and while I'm not quite sure whether it is truly helpful or not, my results have been fine...and the less chemicals the better, right? Then again, you are using pyro...!

-- shawn gibson (s_g@stu.wdw.utoronto.ca), December 29, 1999.

I only use plain water for stop after development. Thanks for responding. Bill

-- Bill Bartels (tlr220@msn.com), December 29, 1999.

Pinholes would be clear on the neg (black on the print), not black on the neg as Bill states his problem to be. Sorry Bill, I've never used PMK, I'm just a curious guy...t (okay, no jokes now)

-- tom meyer (twm@mindspring.com), December 29, 1999.

Just to clarify, The spots I am getting are about the size of a pencil eraser and dark. Sometimes only one spot but can be two or three they usually appear in the denser portion of the negative. I also get pinholes but I know what causes these. Thanks Bill

-- Bill Bartels (tlr220@msn.com), December 29, 1999.

tom's right about pinholes, of course (the reason I was curious in the first place...). This really stumps me. Could it be bad chemicals? I got a bad batch of PMK once, but the problems I had with it were completely different (barely any development at all). Do you place the sheets on something in the tray? If so, maybe it has some chemistry which is reacting with the pyro, which as I'm sure you know is very sensitive to contaminants. If you figure this out, please let us know what it was...and good luck. shawn

-- shawn gibson (SeeInside@hotmail.com), December 30, 1999.

I have been using PMK for almost a year now. I have never had a problem like you are outlining. One thing bothers me. Why are you mixing the PMK then warming it. PMK oxidizes fairly quickly, especially in open trays. I would warm the water first, then pour in parts a & b. Now you have fresh PMK to pour into the tray.

I do not use distilled water except for photoflo and platinum printing. Try mixing the PMK with just filtered ta water. The more variables you can eliminate the faster you will isolate the problem.

I would also try another film.

In addition, tray development with PMK requires constant and substantial agitation. I rock the tray from right to left, then top to botton. This gets old, but results in no streaking. I would almost tend to believe that the spots are some form of streaking or inconsistent staining.

Please keep us posted on your progress.

Mike

-- Mike Kravit (mkravit@mindspring.com), January 03, 2000.

Thanks to everyone for your input. I have not been useing PMK because of my spotting problems, but I will try again with your suggestions. I have been having good tesults with hc-110 developed in tanks with hangers, no spots, no pinholes, negs look great and print easily. Thanks again Bill Bartels

-- Bill Bartels (tlr220@msn.com), January 06, 2000.