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Kodak rapid selenium capacity
"Dan Quinn" wrote in message om... (Fred) wrote Dan wrote: Is that the only reason you are using KRST? You're not interested in the archival properties it can confer? Acutally that's the reason I started using selenium. Any addition of selenium will extend a silver images already long lifespan. I doubt any disagreement of that. A just perceptable, subtel darkening in the shadows will not confer archival properties. That amount will not protect the most vunerable highlight areas. Are you saying that the archive effect of the toner is proportional to the toning effect? At least that is the conventional wisdom. To read quickly an explanation of the preferential toning behavior of selenium, one might think thin areas of silver are immune. Perhaps the dense areas exert some sort of gravitational pull and hoard the selenium untill they've had their fill. I like the idea that the selenium toner serves to protect the print from oxidizing gases. The implication is that the protection covers the whole spectrum of silver density on the print even though the selenium increases the shadow densities in prints with little or no change in the image tone. I believe that implication correct, but for some reason though, tests have showen that the highlight areas are still vunerable. Keep in mind we have to start a very long lasting base silver image. Silver-gelatine with no after treatment can last generations, even a century or more in good condition. I think there are quite a few who do tone but not for it's lengthening the life span of the print. BTW, have you considered dilution and carry out of the solution when costing that KRST? Dan I just divided the suggested number of prints capacity by the cost. I've never used selenium toner untill last week. I guess if I want more toning effect from selenum, I'll try a warmer tone paper. Nelson's Gold Toner may be your ticket. It is a sulfide plus Gold toner. I've read that it can be used at room temperature although more usually at 100-110 F. Ready-Mix can be bought from Photographer's Formulary. Cost per print is a small fraction of KRST. For more Info search this NG for, nelson's gold . I compound all my own chemistry. I've all the chemicals for Nelson's but have yet to mix the toner. I'm wraped up in refining my print developer test methods and testing some new formulas. Dan Nelson's is a good toner where partial toning is desired because it does not split tone. It also gives a somewhat different color than other direct toners. The best source of instructions is the patent. Some of the reprinted instructions in Kodak handbooks leaves out the very important step of refixing the prints after toning. This is vital if they are to be permenant. The patent number is USP 1,849,245 This is available from the U.S. Patent and Trade-Mark Office site at http://www.uspto.gov you will need a browser plug-in to display the fax tiff files. The best is Alternatiff, available as freeware off the web. Do a Google search to find it. The tiff files can be viewed off line and printed using the Windows imaging program. A good toner for protective purposes is Kodak Brown Toner or Agfa Viradon. These are both concentrated polysulfide toners. Both tone uniformly. The color of the image will depend on the color of the original but the shift is greater on cold tone papers than from KRST. A visible change is sufficient to impart substantial protection to oxidation. Both toners must be used with a 10% sulfite bath following toning as a sort of stop bath. Polysulfide toners have the peculiar property of toning faster as they become exhausted or diluted, so, any toner retained in the paper when it enters the wash bath will continue to tone untill substantially washed out. If washing is too slow it will cause a peach-colored stain in the highlights. The sulfite bath eliminates this problem. The current toner recommended by IPI for microfilm use is a polylsulfide toner. KBT, Viradon, or Kodak T-8 will all work. While KBT is used at 100F for rapid toning it will work at room temperature but very slowly. This may actually be an advantage if one wants just slight toning. No fixing is required after a polysulfide toner. The main drawback to these two toners is odor. The odor is not too strong unless the toner becomes exhausted but there is still some "rotten egg" odor. -- --- Richard Knoppow Los Angeles, CA, USA |
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Kodak rapid selenium capacity
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#14
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Kodak rapid selenium capacity
"Richard Knoppow" wrote Coffee filters work fine and are cheap. And the cheapest coffee filters work the finest. I bought some fancy Melitta filters (for making coffee) and they have little _holes_ in them, something about "letting the flavor through". -- Nick Lindan |
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Kodak rapid selenium capacity
On Tue, 03 Feb 2004 16:00:51 GMT, "Nicholas O. Lindan"
wrote: "Richard Knoppow" wrote Coffee filters work fine and are cheap. And the cheapest coffee filters work the finest. I bought some fancy Melitta filters (for making coffee) and they have little _holes_ in them, something about "letting the flavor through". feb304 from Lloyd Erlick, I agree about the cheapest paper filters. But it's possible to use them inconveniently (solution flows through very, very slowly) or conveniently. 'Conveniently' allows air to stay 'behind' the paper filter. If the filter is put into an ordinary funnel, it will stick to the smooth surface and filtering will take place only at the bottom over the hole. Therefore, either use a funnel made for coffee filtering - it has ridges inside meant to prevent the filter from sticking to the funnel - or get one of those permanent stainless or plastic filters, put the paper filter inside it, and put the whole thing into a plain funnel. This will be even faster than the ridged coffee funnel. (The permanent filters are a bit coarser than paper, so the paper filters are better for toner.) When I drank coffee (sigh) I cut a chunk out of an old cotton t-shirt. It filtered my coffee for years, and rinsed clean in a moment. For toner, I like a disposable filter. regards, --le _______________________________________ Lloyd Erlick Portraits, 2219 Gerrard Street East, unit #1, Toronto M4E 2C8 Canada. --- voice 416-686-0326 http://www.heylloyd.com _______________________________________ |
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