yesterday night I've iodized a few more 4x5" calotype sheets to fit my graflex... This time under a red safelight, the same I use for bromide papers and liquid light emulsions and which never gave me fogging problems with those. The washing part has been carried in total darkness as I left the room for an hour and half, leaving the papers in running tap water.
Well, today I exposed a couple of such calotypes, but during sensitizing (still in safelight), they turned again black as the sensitizer touched the sheets!
I tried to expose a dark sheet anyway but result didn't change. I also tried to expose a iodized but non sensitized paper but it turned black anyway after exposure during development (similar gallic acid + silver nitrate + acetic acid solution used for sensitizing).
There's something bad that happens when the gallo-nitrate solution meets the silver iodide paper. I've left also a iodized paper in complete light for half day, masking half of it with a book. There was no change in the paper, no signs of exposure nor differences of tone: just an uniform white-yellowish color.
Although is always a good idea to work in dimmed light or safelight conditions, maybe I should assume that the papers were not fogged during iodizing or afterwards... Talbot and pioneer calotypists used to work in candle light or dimmed light and this kind of tecnique should print veeery slow and shouldn't take light from a 4w safelight! (I use a led safelight, its wavelength falls in the red spectrum and is very realiable with modern fast papers).
Could it the post-iodizing wash bat insufficient? My sources state 1-2hrs, one source generically suggest "several hours". I noticed that badly washed iodized calotypes turn brownish and the papers I got here were clear.
I'll try to ask for help in some chemistry group on usenet or somewhere else... I'm surprised though there are not many calotypists around... Even on alternativephotography.com there's no recipe for a calotype negative and calotype negatives are listed as a "forgotten process"!
new day, new experiment, same result
Since the papers iodized in red light turned black anyway, I started figuring that it could have been due to an excess of silver nitrate. So I made a new batch (again in the safelight) of iodized papers, this time using a merely 1% silver nitrate solution. Today I was about to expose them, but they still turn black when the solution of silver nitrate gallic acid and acetic acid comes into contact with the iodized paper. For another sheet I also tried to reduce the amount of silver nitrate in the sensitizer, but that didn't set a difference. I've finally exposed a paper without sensitizing it before, but then when you have to develop it in a similar solution of the three chemicals mentioned, it turns irreparably black again.
I tried to contact Richard Morris, a guy who wrote an article in "Coming into focus" (book edited by John Barnier) which has been a good source for me for many old photographic tecniques. I hope he will reply and help me sort out what is wrong.
This is, once again, a stab at randomness, but have you tried putting a drop of the sensitizer on non-iodized paper? Perhaps its an interaction with the paper ...
yep I did that on 2-3 different papers I used: the sensitizer remains transparent and the paper clear. The sensitizer itself tends to become darker (although not really deep black) if left in the light & air for very long (for ex. I accidentaly left a small plastic glass with some sensitizer in the darkroom for 3-4 days and it turned dark).
Originally Posted by htmlguru4242
I've found a XIX century text covering calotype making among other processes:
There are some alternatives proposed by Talbot himself, like iodizing, the brushing with gallic acid first and later with silver nitrate, I tried that too without any success.
One thing it is left to try would be to have the iodized paper washed in distilled water instead tap water: perhaps organic compounds and carbonates found into tap water react with silver...
could it be the paper you're using?
For another take on how to do Calotypes, try:
If I remember my reading from this book, one of the things he does is to wax the paper (this may be AFTER making the negative, but I don't recall).
Here is a quote from the chapter description on Amazon-
Chapter 4, "Calotype Paper Negatives", is dedicated to 2 types of paper negatives: wet-paper process and waxed-paper process. Wet-paper is considered most appropriate for portraiture because the negatives must be used quickly after sensitizing, before they dry out. Waxed-paper requires longer exposures but is dry and need not be used quickly. These negatives are suited to landscape, architecture, and anything that requires time to locate. There are lists of recommended papers for both processes. Step-by-step instructions take the reader through Iodizing, Sensitizing, Exposing, Developing, and Waxing the negatives. You can choose from several recipes for Iodizing and Sensitizing solutions.
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waxing is generally raccomanded after the negative is printed and developed; waxing allows a better transparency, resulting in a paper negative easier to print... Also oiling is suggested as an alternative to waxing. It makes sense...
Originally Posted by TheFlyingCamera
I've found another source for calotypes...
they're based on the notes of a certain Greenlaw who described some variation of the process in 1869. Tonight I will try some of these alternatives and let you know.
(by the way, the link above directs to a very interesting website, with a lot of both technical and historical informations on early photographic processes)
Last edited by Fulvio; 11-06-2006 at 11:33 AM. Click to view previous post history.
I tried the methods described in that PDF document, but I still have the same problems: whenever the gallic acid mixed to silver enters in contact with silver iodide on the paper, this turns black, even if unexposed.
I thought this was due an insufficient washing or organic contamination of the iodized paper while in the washing bath. So I gave a try to the washed precipitate method. It is quite easy. With such method, I mixed silver nitrate (11.4%) and Potassium Iodide (5.6%) in equal parts. A precipitate forms and sits on the bottom of the solution. Then I started decanting all the liquid, leaving only the precipitate. I added distilled water and repeated the operation, washing the precipitate with several changes of water. Then finally I added a certain amount of potassium iodide until the precipitate redissolved becoming a very milky solution. I've spread this solution onto the paper; the paper became yellowish. When dried, I applied a solution of 11.4% silver nitrate without drying the sheet (operation carried under safelight). By doing so and exposing the negative immediately, an image forms on the paper. I tried this overnight so I pointed the camera (a 4x5" Graflex) toward a lamp. After 20' exposure at f8, I developed the paper with usual solution of gallic acid + silver nitrate. I could finally see the shape of the lamp's light bulb (very dark) surrounded by a very dirty gray area. I had to stop immediately, otherwise all the image would have turned black. So I tossed the negative into fixer and the image fixed. Now I have this big gray spot with a dark light bulb image negative
But although I can call this somewhat satisfactory in a sense, it's a very odd result.
Calotypes should be supposed to develop in a very long time. All the sources mention developing times of ten to sixty!!! minutes. When I pour a diluted solution of gallic acid and silver nitrate over a iodized sheet of paper, this turns black in a few seconds.
Today I made new experiments, but this time I was unable to deliver anything like yesterday.
For example, I made another experiment by immersing the paper straight in the 5.6% potassium iodide solution. The paper doesn't turn in any color. After it is dried, I start coating it with a 11.4% silver nitrate solution. The paper turns yellow (I do this in safelight, but I've realized later what color the paper is then). After paper is coated, while the sheet is still damp, I start exposure. An image forms on the paper and you can clearly see it after you open the film holder of the camera. But then, when you try to develop it with gallic acid & silver nitrate, it turns completely black.
I tried not to develop a sheet iodized with this method ("no pre silver bath") in a gallic acid developer. Instead, I tried standard b+w developers and also plain water, like I do for van dykes and salt prints. But the image won't develop or just turn slightly darker (probably due to the contact of silver nitrate with organic compounds in water - it doesn't turn black as with gallic acid, though).
I want to try now the Greenslaw process, which is another no-pre-silver method, but involves use of elemental iodine as an additive to the iodizing bath. The authors of that PDF have been successful with that method. Actually it looks like that all of my sources have been successful with their own method, but nobody mention this problem with gallic acid and I still have to understand what's wrong with mine. I'd wish to be a chemist in such moments...
Now if you excuse me, I'm going to bang my head on the wall
Perhaps you are overexposing?
Everything I've read metnions there being no image on the page after being removed from the camera ...
Note: I am not making calotypes (yet) but have you read Richard Morris' article in Coming into Focus? I suppose you know what a buckle brush is, but in case not, it's basically a small plastic or glass pipe with a wad of clean cotton in one end. It is necessary to use this tool, as this process seems to be very dependent on cleanliness and not getting things contaminated. Hope it helps in some way.
1. using a buckle brush, sensitize the paper with 7.5% silver nitrate solution.
2. Immerse the paper totally in 5.6% potassium iodide solution for at least 2-3 minutes. It will turn primrose yellow.
3. Wash paper for several hours to remove the potassium nitrate. Hang to dry.
Solution A: Add 11.4 grams of silver nitrate into 75 cc distilled water, mix thoroughly and finally add distilled water to make 100 cc.
Solution B: Into 28.4 cc solution of A, 5.5 cc glacial acetic acid.
Solution C: Into 100 cc of distilled water, add gallic acid and mix thoroughly until no more will go into the solution. This is a saturated solution of gallic acid.
Solution D: (working solution) Add three drops of B and three drops of C into 4 cc of distilled water. This will cover a full plate (6.5 by 8.5 inches). Mix this fresh every time you sensitize an iodized paper.
1. With a fresh buckle brush, coat the paper with working solution D onto paper.
2. Blot the paper carefully with a clean blotting paper evenly all over. Let dry in the dark. The paper should be slightly moist when it goes into the camera.
3. Cut paper to size and put in holder. This can be done under red safelight.
1. Using the solutions B and C mixed together in equal quantities, 5 cc each for a full plate negative, brush this over the calotype negative. The article says the image should "appear almost immediately".
2. Use another separate, clean buckle brush. Apply an unspecified amount of solution C. Don't get the paper too wet. Allow the image to develop until it stops increasing in density, then recoat again with solution C. The density can be checked, as this can be done under red safelight conditions.
3. Wash briefly in tap water, then fix in plain hypo solution for five minutes until yellow potassium stain is gone. If five minutes isn't enough to remove stain, continue to wash.
4. Wash thoroughly for 10 minutes in HCA or else at least for one hour.
5. Dry face up on fiberglass screen.
There could be faults in this, but I've checked it in some detail. If unsure about the steps in the process, look in Coming into Focus by John Barnier, ISBN 0-8118-1894-2.
Last edited by Jerevan; 11-07-2006 at 12:02 PM. Click to view previous post history.
Reason: Punctuation and spelling
“Do your work, then step back. The only path to serenity.” - Lao Tzu
Originally Posted by htmlguru4242
The only partially successful calotype (if can be so defined) of the "light bulb" I have, required an exposure of several minutes. And in the picture there's only the shape of the light bulb, but not that of the lamp.
Even with the no-pre-silver method, when I can directly see somthing on the negative before development, I'd say that the speed is more or less the same of a salt print - which is rather slow (mine print in 5-8 minutes under strong UV lights).
Anyway I also thought about the possibility of having a very fast calotype in my hands. So I tried exposures as short as 1 minute f11.
The problem is when I try to develop anything: it turns black.
It can't be a problem of contamination as I use only distilled water and, yes, I'm using the buckle brush whenever possible.
Last edited by Fulvio; 11-07-2006 at 02:12 PM. Click to view previous post history.