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Caffenol (was Doing everything wrong with PMK Pyro)
Jim Phelps wrote:
"Donald Qualls" wrote in message . com... BTW, if you like staining developers (and after printing good PMK negatives, you probably will) you should investigate Caffenol. Saw the thread on Photo.net (who's nipple?). May give it a shot. Do you have a better formula other than by teaspoons? That's the way it came to me. The end result is the coffee is four times "normal" drinking strength, and in fact it's been verified, last time this went around, that you can use espresso to replace the water and coffee crystals -- that is, simply alkalize espresso straight from the machine (after suitable cooling, of course). I didn't find my reloading scale while packing for this last move (it's probably in a box that hadn't been unpacked from the previous move, and I likely won't see it for several more months), and the only other almost suitable scale I own measures in 5 gram increments, so I can't measure how much coffee and soda that is by mass, but I've used this with both coffee and washing soda taken from the tops of newly opened packages, so you should a) find it easy to reproduce, and b) find it fairly simple to weigh the ingredients after measuring. You might be able to get the mass from the "serving size" on the nutritional information panel on the coffee, at least; the "slightly rounded" teaspoons I use are approximately 1.5 level teaspoons (so you could say I'm using 6 level teaspoons). The washing soda, as packaged, seems to be very similar in density, but the water content is unknown and probably varies depending how long the stuff has been in the cardboard box; it probably starts as anhydrous, but converts to monohydrate in storage, and there's no simple test (other than to heat some to constant weight and determine how much water was driven off) to determine how far it's gone along that path. Complicating matters still more is that different brands of instant coffee have different levels of activity, likely corresponding to different levels of the caffeic acid (a pyrocatechin variant) and its glycoside precursor, chlorogenic acid, that are the most likely developing agents -- which, in turn, likely stem from beans grown in different conditions, and/or cofee roasted or brewed differently and/or converted to instant by a different method. Folger's is freeze-dried, made from Columbian Arabica beans grown in mountain conditions, and roasted relatively light -- the only other data point I have on this is that a German instant coffee (I've forgotten the brand), which I'm assured is 100% coffee and 100% arabica beans, required 50% more of the powder to do the same job. If you want to make something really consistent here, you'd do well to chase down industrial sources of pure chlorogenic and/or caffeic acids (if there are such sources), or find an analytical method of extracting and purifying one or both, and test with known quantities. If you could do it economically, you could probably sell the resulting developer as a low-toxicity competitor to pyro and pyrocat formulae... Fortunately, the carbonate, at least, isn't very critical; I've seen no difference at all from increasing it 50% (I was hoping I might speed up the working, but I'd have to have a stronger alkali to increase pH -- next time, perhaps I'll try adding a tiny bit of lye), and I'm reasonably sure the amount given has at least a little excess. It seems less dense than sugar, so the spoons likely contain less than 5 grams; since more doesn't hurt, you should be safe assuming 10 g of sodium carbonate anhydrous in 8 ounces, or roughly 40 g/L. Ah. The photo you're referring to (in which Tri-X masquerades as color film due to interaction of the stain with scanner corrections) is one my wife would prefer no one saw, so I haven't told her... -- I may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. |
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On Wed, 13 Oct 2004 01:54:33 GMT, Donald Qualls
wrote: The end result is the coffee is four times "normal" drinking strength, and in fact it's been verified, last time this went around, that you can use espresso to replace the water and coffee crystals -- that is, simply alkalize espresso straight from the machine (after suitable cooling, of course). Heavens to Starbucks !! The next thing is they'll be using tea or soda !! Regards, John S. Douglas, Photographer - http://www.puresilver.org Please remove the "_" when replying via email |
#3
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John wrote:
On Wed, 13 Oct 2004 01:54:33 GMT, Donald Qualls wrote: The end result is the coffee is four times "normal" drinking strength, and in fact it's been verified, last time this went around, that you can use espresso to replace the water and coffee crystals -- that is, simply alkalize espresso straight from the machine (after suitable cooling, of course). Heavens to Starbucks !! The next thing is they'll be using tea or soda !! In fact, green tea and mint have been used; green tea contains chlorogenic acid, though in much lower concentration than coffee, and tannates that might be distantly related to pyrocat, while mint seems to develop via thymosin (possibly along with chlorogenic acid, which is present in all green plant parts, but tends to concentrate in green fruits) -- oddly, since thymosin is oil soluble, mint has a tendency to develop more strongly in the top 25% of the tank, because the mint oils float on water; recommendation is to put one film in the bottom half of a two-reel tank with 2x the liquid needed to cover the film. Soda (at least ordinary cola) doesn't seem to work -- caffeine itself doesn't appear to be a developing agent, and sugar is a restrainer; diet soda would be a better choice, if caffeine were in fact a developing agent -- but a brew made with straight caffeine obtained from OTC stimulants (No-Doz etc.) has been reported not to develop film. -- I may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. |
#4
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I'll bet the writes of that old TV program Mcguyver are kicking themselves
for overlooking Caffenol. |
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jjs wrote:
I'll bet the writes of that old TV program Mcguyver are kicking themselves for overlooking Caffenol. Nah, they did it, or nearly so -- or did you miss the episode in which MacGyver developed film from an aerial camera in orange juice (presumably the ascrobic acid was to have done the job, though they glossed over preservation and alkalization, even while they got it right about the negs, straight out of the dev without stop or fix, being milky and turning black as they were viewed, from residual developer action). If he'd used coffee, he could have used the orange juice for stop bath and been able to look at the pictures for hours, if need be... -- I may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. |
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On Wed, 13 Oct 2004 11:04:29 -0500, "jjs" wrote:
I'll bet the writes of that old TV program Mcguyver are kicking themselves for overlooking Caffenol. Personally I have better things to do with my coffee ! And also my tea. Regards, John S. Douglas, Photographer - http://www.puresilver.org Please remove the "_" when replying via email |
#7
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John wrote:
On Wed, 13 Oct 2004 11:04:29 -0500, "jjs" wrote: I'll bet the writes of that old TV program Mcguyver are kicking themselves for overlooking Caffenol. Personally I have better things to do with my coffee ! And also my tea. No, John, don't think of it as "coffee." This is instant we're talking about, after all. Think of it as a very inexpensive photographic chemical that's sold in the coffee aisle of the supermarket -- it's certainly not fit for drinking! And while you're in the market, be sure to grab a box each of Arm & Hammer Photographic, er, Washing Soda and 20 Mule Team Photographic Borax -- they'll be in the laundry aisle. -- I may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. |
#8
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"John" wrote in message
... On Wed, 13 Oct 2004 11:04:29 -0500, "jjs" wrote: I'll bet the writes of that old TV program Mcguyver are kicking themselves for overlooking Caffenol. Personally I have better things to do with my coffee ! Have you ever noticed that Guinness and old Rodinal have exactly the same appearance? Clue: don't drink Guinness from a lab beaker. |
#9
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Donald Qualls wrote:
John wrote: On Wed, 13 Oct 2004 11:04:29 -0500, "jjs" wrote: I'll bet the writes of that old TV program Mcguyver are kicking themselves for overlooking Caffenol. Personally I have better things to do with my coffee ! And also my tea. No, John, don't think of it as "coffee." This is instant we're talking about, after all. Think of it as a very inexpensive photographic chemical that's sold in the coffee aisle of the supermarket -- it's certainly not fit for drinking! And while you're in the market, be sure to grab a box each of Arm & Hammer Photographic, er, Washing Soda and 20 Mule Team Photographic Borax -- they'll be in the laundry aisle. Hooray for the supermarket! I've been getting some of my chemistry there for years, but I missed out on the thread about the Caffenol, Donald. Care to share it; I may even have a jar of instant developer in my pantry where I occasionally use it for baking pumpernickel bread. Is there really a use for it in the darkroom too? |
#10
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LR Kalajainen wrote:
Hooray for the supermarket! I've been getting some of my chemistry there for years, but I missed out on the thread about the Caffenol, Donald. Care to share it; I may even have a jar of instant developer in my pantry where I occasionally use it for baking pumpernickel bread. Is there really a use for it in the darkroom too? Absolutely. Basic Caffenol (from a 1996 recipe by Roger Bunting) is as follows: 2 level tsp. Arm & Hammer Super Washing Soda 4 slightly rounded tsp. Folger's Coffee Crystals (or direct copy -- I use Fred Meyer brand) in 8 ounces water. Add the soda first, stir until completely clear (to let microbubbles rise), then add the coffee and stir until all muddiness is gone (same thing). Most films like 25-30 minutes at 68 F. Developer produces excruciating sharpness, very crisp grain, and a stain similar to pyrocat or pyro. Smells pretty bad, though, like a broiler pan with 2-day old roast beef fat left in it. Got Tech Pan or microfilm? Make it Caffenol LC with half the coffee; produces nice pictorial contrast and excellent sharpness with Imagelink HQ, Copex Rapid, and probably with Tech Pan and other document films. Developing time about the same, 20-30 minutes at 68 F. With conventional film, expect full film speed or even 1/3 stop increase. With microfilm, I've had good results shooting Imagelink HQ at IE 50 (one stop faster than normal for pictorial use of this film) and Copex Rapid at 80-100 (again, one stop increase). -- I may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. |
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