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Selenium, negative intensifier and curves
If anyone has already checked this I would appreciate the info. When
using selenium as a negative intensifier, does it change the curve proportionally or does it change it non-proportionally? As I understand it(and my experience seems to support this), selenium toner used to intensify film can get about 1 grade (0.3) of increased density. When toning paper, selenium seems to affect the darks proportonally more than the lights. This would lead me to believe that using it to intensify a negative would affect the highights proportionally more than the shadows. Now I can test this by exposing a negative with a step wedge, checking it on a densitometer, intensifying it and checking it again. But if anyone has done this, I like to know what you found. Thanks |
#2
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"Frank Earl" wrote in message news:5Hhid.31621$SW3.10215@fed1read01... If anyone has already checked this I would appreciate the info. When using selenium as a negative intensifier, does it change the curve proportionally or does it change it non-proportionally? As I understand it(and my experience seems to support this), selenium toner used to intensify film can get about 1 grade (0.3) of increased density. When toning paper, selenium seems to affect the darks proportonally more than the lights. This would lead me to believe that using it to intensify a negative would affect the highights proportionally more than the shadows. Now I can test this by exposing a negative with a step wedge, checking it on a densitometer, intensifying it and checking it again. But if anyone has done this, I like to know what you found. Thanks I can't answer directly because I've never taken a densitometer to a selenium intensified negative. However, the split toning effect of Selenium depends somewhat on its dilution. The split tones That result in insufficient protection come from the use of highly diluted toner (1:20) but becomes less as a more concentrated solution is used. At 1:9 the effect is small enough to provide good overall image protection. It is more even at higher concentrations and as toning is carried toward completion. Selenium toner has some advantages as an intensifier: it is packaged and it is more controllable and reliable than most other intensifiers, the image is also permanent, not true of some other intensifiers. There are more powerful intensifiers but they tend to be less predictable. Probably the best of the lot is chromium intensifier but Selenium is better if it will go far enough. Silver intensifier is the only one resulting in a neutral colored image. -- --- Richard Knoppow Los Angeles, CA, USA |
#3
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"Frank Earl" wrote
If anyone has already checked this I would appreciate the info. When using selenium as a negative intensifier, does it change the curve proportionally or does it change it non-proportionally? As I understand it(and my experience seems to support this), selenium toner used to intensify film can get about 1 grade (0.3) of increased density. When toning paper, selenium seems to affect the darks proportonally more than the lights. This would lead me to believe that using it to intensify a negative would affect the highights proportionally more than the shadows. Now I can test this by exposing a negative with a step wedge, checking it on a densitometer, intensifying it and checking it again. But if anyone has done this, I like to know what you found. Thanks I've used selenium toner (KRST at 1+3 dilutions) for approx. 5-12 min. to many intensify negatives (120, 4x5, 8x10). I don't have a densitometer, so I have no info on your last paragraph. But it did seem to be easily a grade in paper improvement. It's been a few years now but I used to do this to increase contrast in the neg when printing on graded papers. With VC papers I've not been as motivated to selenium intensify. The density increase effect seemed to me to be directly proportional to the amount of density in the original neg. I found it to be very similar to longer negative development time - it gave me a second chance. I preferred it to increasing the paper contrast grade. It worked quite well and it seemed to be foolproof. I never ruined a negative nor was I ever really disappointed. I found that reducing dense negatives (overdeveloped) was not nearly as successful as being conservatively (a little) short in development time and then intensifying only if required. Intensification occurs quite slowly often (depends upon film type) with an increasing plum or blue colour to the neg. It worked well incrementally i.e. try a little, dry and contact print, then if not enough repeat. I used to do it by inspection using two large Pyrex dishes with tungsten lights projecting through the dishes from below. I would visually compare the difference for negs in a holding bath of water with those being toned. The lights also kept the temperature of solutions quite warm which reduced the time and kept the rate of toning consistent. I recommend good ventilation, warm KRST in theses dilutions is very smelly and somewhat irritating. Douglas |
#4
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Frank Earl
Search this NG for, slimt adams . Ansel used selenium to gain one zone. Dan |
#5
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Frank Earl
Search this NG for, slimt adams . Ansel used selenium to gain one zone. Dan |
#6
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On Thu, 4 Nov 2004 12:34:43 -0500, "Douglas"
wrote: ... I recommend good ventilation, warm KRST in theses dilutions is very smelly and somewhat irritating. Douglas nov504 from Lloyd Erlick, A Pyrex baking pan of appropriate dimensions would have made a nice cover to that excellent setup. A nice smell reducing cover, that is. And thanks very much for the detailed observational record. Intensifying negs with KRST is often talked about but rarely do we see the intimate details ... regards, --le ________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: net: www.heylloyd.com ________________________________ ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#7
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On Thu, 4 Nov 2004 12:34:43 -0500, "Douglas"
wrote: ... I recommend good ventilation, warm KRST in theses dilutions is very smelly and somewhat irritating. Douglas nov504 from Lloyd Erlick, A Pyrex baking pan of appropriate dimensions would have made a nice cover to that excellent setup. A nice smell reducing cover, that is. And thanks very much for the detailed observational record. Intensifying negs with KRST is often talked about but rarely do we see the intimate details ... regards, --le ________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: net: www.heylloyd.com ________________________________ ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#8
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Richard Knoppow wrote: "Frank Earl" wrote in message news:5Hhid.31621$SW3.10215@fed1read01... If anyone has already checked this I would appreciate the info. When using selenium as a negative intensifier, does it change the curve proportionally or does it change it non-proportionally? As I understand it(and my experience seems to support this), selenium toner used to intensify film can get about 1 grade (0.3) of increased density. When toning paper, selenium seems to affect the darks proportonally more than the lights. This would lead me to believe that using it to intensify a negative would affect the highights proportionally more than the shadows. Now I can test this by exposing a negative with a step wedge, checking it on a densitometer, intensifying it and checking it again. But if anyone has done this, I like to know what you found. Yes, you can certainly do this and use the data to adjust your negative development time to obtain a "normal" contrast range when toning negatives. I don't know why you would want an arbitary increase in density otherwise obtained through normal exposure and development, though. But as Richard notes with selenium you'd need a lower dilution (at least 1:9 or lower) to avoid split toning. I don't routinely do this using selenium so I've never drawn curves. I do occasionally intensify a negative, but it depends strictly on the negative. For better archival negative toning and more _even_ density I'd use/experiemtn with a polysulfide toner like Kodak brown toner not selenium. Thanks I can't answer directly because I've never taken a densitometer to a selenium intensified negative. However, the split toning effect of Selenium depends somewhat on its dilution. The split tones That result in insufficient protection come from the use of highly diluted toner (1:20) but becomes less as a more concentrated solution is used. At 1:9 the effect is small enough to provide good overall image protection. It is more even at higher concentrations and as toning is carried toward completion. At 1:9 it will affect all densities. Though it will add greater density to highlight areas, it can add slight but significant density to shadow areas. It will increase local contrast accordingly. I think you really need to be careful though and very sure about using it for the results desired. As an intensifier, it might be remembered you don't have to intensify the entire negative, but just those areas where greater local contrast is desired. Selenium toner has some advantages as an intensifier: it is packaged and it is more controllable and reliable than most other intensifiers, the image is also permanent, not true of some other intensifiers. There are more powerful intensifiers but they tend to be less predictable. Probably the best of the lot is chromium intensifier but Selenium is better if it will go far enough. Silver intensifier is the only one resulting in a neutral colored image. -- --- Richard Knoppow Los Angeles, CA, USA |
#9
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Tom Phillips wrote
I don't know why you would want an arbitary increase in density otherwise obtained through normal exposure and development, though. Probably because some negatives to be printed are not ideal. I've negatives from the 30s and some of my own from the 60s, which for sure will need something. What I'd like to know is if I intensify with selenium will it work well with generations old negatives. Dan |
#10
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Tom Phillips wrote
I don't know why you would want an arbitary increase in density otherwise obtained through normal exposure and development, though. Probably because some negatives to be printed are not ideal. I've negatives from the 30s and some of my own from the 60s, which for sure will need something. What I'd like to know is if I intensify with selenium will it work well with generations old negatives. Dan |
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