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View Full Version : "Taco" methos developing problem + some newbie questions



Arthur Fleischmann
26-Apr-2009, 14:39
Hello forum members,

I am very new to large format photography, just a few days ago received my first 4x5 camera, a Shen Hao PTB 45. I usually (in medium format) shoot in colour but I got some cheap Efke PL 100 4x5 B&W film to learn to use the new camera and format.

I have processed B&W film before, however only 35mm and medium format. I read about the "Taco method" and since I own several Paterson tanks I decided to give it a try. Attached is a quick test shot I took in my kitchen. I think I should have developed a little longer (I used Ilfosol 3 developer and had to guess the time as I couldn't find any developing time for Efke 100 in this developer), but besides that obviously something went wrong, development is kind of uneven (see attached image).

Any ideas what I did wrong?

Also, I am thinking of trying developing in trays. I have read about this but am unsure if I have understood everything correctly, so here are some questions.
- You place several sheets of film on top of each other in a tray, all sheets emulsion side down, then you continuously take the sheet from the bottom of the stack and place it on top? Do you also rock the tray in addition to this shuffling motion?
- If I only develop one sheet, do I just constantly rock the tray? Is it also possible to place two 4x5 sheets next to each other (opposed to on top of each other) in an 8x10 tray?
- How much developer do I need to use, just enough to cover a sheet (or the stack of sheets) or more?

Sorry, lots of questions... I took some more pictures today but don't want to develop them before I know what I did wrong with the test negative. Your help is appreciated! :)

Gem Singer
26-Apr-2009, 15:21
Looks like you might have rolled the sheet of 4X5 film with the emulsion side outside instead of inside. I can see a horizontal line in the middle where the rubber band blocked the developer from reaching the film.

Tray development is simple to use and will solve your problem, but it needs to be carried out in total darkness.

There are several methods to develop cut film in daylight. These include developing tanks, tubes, rotary drums, etc.

You will find an excellent description of the tray development technique in Ansel Adams book, "The Negative".

There is also a detailed description in S.Anchell and B.Troope's book, "The Film Developing Cookbook".

Also, there are several methods described on the home page of this website.

Arthur Fleischmann
26-Apr-2009, 15:32
Thank you, Gem! I don't think the rubber band was the problem, though. As you say the line in the picture is horizontal, if it was caused by the rubber band it should be vertical (refering here to the picture in portrait format).

Gem Singer
26-Apr-2009, 15:45
Arthur,

Sounds like you are still hell bent on continuing to use the "Taco" method. Try rolling the film into a five inch long roll, instead of a four inch roll. Just make certain that the emulsion side is inside of the roll so that the rubber band contacts the base side if the film.

Arthur Fleischmann
26-Apr-2009, 16:00
Well, I haven't decided yet. I'm not sure if the taco technique caused the problem or something else. The obvious advantage of the taco method is it can be done in daylight. Anyway, thanks for your suggestions, I'm quite sure the emulsion side was on the inside when I developed this sheet. A five inch long roll of film won't fit in the tank, I'd have to use a taller tank and more chemicals and I don't see the benefit of doing so compared to a four inch long roll in the smaller tank.

Ok, I'll try to find more information on tray processing.

BradS
28-Apr-2009, 21:57
Well, If I understand you correctly, it can't be the rubber band...it almost looks like...hmm, not sure but, I don't think that the defect has anything to do with your development. The taco method works great. I used it quite a bit before I got a Jobo Tank. The secret to the taco method is to do the Hypo clearing agent in a tray - with the rubber band removed.

dagabel
29-Apr-2009, 07:06
Hi Arthur - I've had success with this version of the taco method:

http://www.largeformatphotography.in...ad.php?t=30099

Thanks,
Duane

dagabel
29-Apr-2009, 07:10
Sorry - bad link cut-n-paste! Try this one:

http://www.largeformatphotography.info/forum/showthread.php?t=30099

Thanks,
Duane

Doremus Scudder
29-Apr-2009, 09:23
Arthur,

Your problem looks to me like a drying mark or as if the film were only partially submerged in one of your solutions (probably the developer) for a short while. I would imagine that you can make your taco method work by refining your technique. Do pre-soak, and do pour the solutions into and out of the tank as quickly as possible to minimize the time the film is only partially covered by solution.

That said, I am a tray-developer and find it low-tech, simple and flexible. However, it requires a modicum of skill and practice. There is a lot of info here and elsewhere about the technique. You can search on my name to find my particular technique (I posted it here or on APUG not long ago...).

Just a couple of observations that might help if you do decide to go with tray processing. First, as mentioned, it must be done in total darkness. It is good to practice in the light with scrap film first and then try with eyes closed until proficiency is gained. You will need trays without rough spots that can scratch. I like the Paterson trays (I use 5x7 trays for 4x5 film). Although many develop emulsion-side down, I find that it can cause uneven development due to the ridges in the bottom of the tray. Emulsion-side-up is a bit riskier, so you have to be more careful about scratching, but I believe the evenness is better. Shuffling is done by taking a sheet from the bottom and placing it on the top of the stack. Turning the films 180 when shuffling helps with evenness. For consistency, I try to go through the entire stack in a specific time (for me, the first half of the developing time I shuffle through the stack once every thirty seconds; for the second half, once per minute). This stays constant even if the number of films changes, guaranteeing that all films have very close to the same number of agitations for the entire developing time. However, you need to calculate your shuffling rate depending on the number of films you develop. At once through the stack every 30 seconds, the rate for three films would be one shuffle every 10 seconds; for six films, one shuffle every five seconds, etc. I like to develop in batches of six, but do develop up to eight at a time. For single sheets I double the agitation rate, i.e., two lifts out and back into the developer every thirty seconds. This is correct since the film on the top of the stack gets an "extra" agitation when the next sheet is place on top.

Hope this helps some,

Best,

Doremus Scudder