negatives for kallitype
I've been debating the idea of trying to do some alternative processone of these months/years, and based on what I've read the Van Dyke or kallitype seems like the one to try. I like the color control with kallitype, so thats in the lead. But thanks to a long, rich family history of cancer and general klutziness on my part, I refuse to mess with known carcinogens like those used for contrast control in kallitype. Minor chemical burns, I can probably live with. I'm not going to change my mind, so lets avoid that debate.
Based on my limited understanding, that leaves me either needing to make digital negatives so that I can control the contrast, or making perfect negatives. The former probably isnt going to happen anytime soon even if I wanted it to, so I think that leaves only perfect negatives. So how hard is it to achieve that goal? I realize it will restrict my subject matter somewhat, but if I overdevelop contrasty scenes can I get consistantly suitable negatives for kallitype that dont need chemical contrast control?
You can make in camera negatives fo use with kallitype. The answer lies in the film used and testing.
I assume from your statements about chemical dangers that you do not use one of the staining developers.
Begin with a medium speed film, I prefer FP4+, and increase your normal development time about 40% to start. A quick test for development time would be to expose three sheets of film identically. develop one normally, one 40% longer and one twice as long as normal.
(Faster films do not expand as well as medium and slow speed films.)
Print each of them on kallitype and decide which yields the print closest to what you like. You will likely discover that your development time will fall somewhere between two of the times used and you can adjust accordingly.
As far as developers for kallitype go, some are less hazardous than others. Ktypes will develop in an amazing variety of things. I have even developed them in 7-Up when demonstrating this fact to students.
The sodium citrate developer is a very safe developer, consisting only of citric acid and sodium carbonate.
The contrast agent used with the developer is potassium dichromate. It is classified as moderately toxic by skin contact and ingestion and highly toxic by inhalation, and a *suspected* carcinogen. You can buy it in solution from B&S which avoids the inhalateion issue. Dichromates are no more toxic than many substances in common use in photography, including hydroquinone and many other reducers, selenium, the ferric salts we use in vandyke and kallitype printing (ferric oxalate and ferric ammonium citrate). If used with the same care we should give all toxic substances used in the darkroom the risks of dichromate are very small, IMO.
Originally Posted by Wayne
wear gloves and do not snort the liquids. Now you have avoided the hazards.
Use nitrile not latex.
Originally Posted by Aggie
Plastic print tongs will also work.
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I have not done kallitype, but I have printed VDBs. I try for perfect negatives. After a couple of years trying different methods, I've been using BTZS to determine exposure and development - I brush develop one negative at a time. So, IMHO, the answer to your question is work hard to achieve perfect negatives. It's possible to do.
Well I did say I didnt want to go there, but since you insist. Aggie, wearing gloves and not sniffing liquid chromium compounds does not necessarily mean avoiding the hazard. Accidents happen. Glass can break, spills can happen, compounds can become airborne. There isnt much room for accidents with carcinogens when your father had 3 types of cancer, your mother one (so far), your sister lost an eye to an exceedingly rare cancer, and you yourself (ie me) had skin cancer in your twenties and undoubtedly will again before its all over. I'm also an ex-smoker. Dichromates cause lung cancer, and I have already used my "get out of cancer free" card. I love photography, but not that much.
Sandy, I'm not sure why you think that dichromate is a potential carcinogen. It has been considered a known carcinogen for years by the International Agency for Research on Cancer. The (US) National Toxicology Program states "Chromium hexavalent (VI) compounds are known to be human carcinogens based on sufficient evidence of carcinogenicity in humans". I havent read their studies but I've seen some of the stats. Their conclusion is based on numerous lung cancer deaths in the chromium and related industries, and experimental research. If you have knowledge of some research evidence that contradicts them I would love to see it, but until then I will have to take their word for it. I have also read that it is just a "possible" carcinogen, but that seems to be only wishful thinking as I cant find any basis for that conclusion. The evidence I have seen suggests has convinced me that it is much more of a risk than other darkroom chemicals, at least for cancer.
Lastly, no I dont use staining developers though I have considered it. But they are not known carcinogens. I am willing to take some risks but not others.
With that hopefully behind me, thanks for the other tips everyone.
Jim, I think I already have some negatives that might work. I not only developed some FP4+ negatives by +40%, I also used the wrong (too concentrated) dilution on them! They might be too dense.
Juan, what was your best method before going to BTZS? Is there something you prefer about the Van Dykes over kallitype? I dont currently have any real sensitometry capability beyond my spot meter, an EM-10 and a step wedge, so i will stick to trail and error for now. I might get myself a densitometer some day, but it wont be for at least a few months and probably longer.
Sandy, this is a bit OT but what is the (dis)advantage(s) of your system of making kallitypes (different chemicals etc) over the others? For example the Formulary makes a kit that is almost identical to the process described in "Keepers of the Light", both of which are diferent from yours. I havent looked to see what B&S's kit consists of yet, and I havent decided whether to get a kit or mix yours up myself. I havent even decided 100% whether I will do kallitype or Van Dyke first.
Regarding potassium dichromate, yes, chromium is a known carcinogen and were I you I might well avoind it myself. However, in the minutely small amounts that dichromate is used as a contrast agent in kallitype and Pt./Pd. printing (typical would be 1ml of a 5% solution of potassium dichromte in a liter of developer) I personally do not believe there is any health risk involved.
My articles at unblinkingeye and the alternative photography site clearly state that my kallitype method is based on 1) simplicity and 2) permanence. This is achieved by the use of one developer and toning with one of the noble metals.
BTW, I am fairly certain that you could obtain contrast control with kallitype using the Na2 method that many people are using with Pt./Pd. printing. See Dick Arentz's website for dilutions of Na2 to match Pt./Pd. printing to negatives of various contrast. Since light sensitivity is based on ferric oxalate in both kallitype and Pt./Pd. the contrast controls that work with one process should work with the other.
Originally Posted by Wayne
Last edited by sanking; 03-09-2006 at 08:09 AM. Click to view previous post history.
Like you, I am about to start on Kallitypes (just waiting to build a big enough order for Bostick & Sullivan to cover international freight overheads). I would still like to do silver printing with my negatives so I have decided to create copy negatives with ortho film. I'm hoping this will allow me to adjust contrast in the darkroom whilst still leaving the processes for my more critical, original negatives intact. In reality I'm limited to 4x5 so I need to make some form of enlarged negative anyway - I figure I may as well do my contrast adjustments at the same time.
I only skimmed the article at unblinkingeye and your explanation didnt jump out at me. I do vaguely recall the part about toning. I'll certainly reread it thoroughly if I decide to go that route.
Originally Posted by sanking
Thanks for the info about Na2. I was going to ask if there wasnt another possible chemical contrast control method, but I figured that I would have encountered it in my reading. I will certainly check into that!