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#1
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pushing time shorter than normal time?
i noticed in Kodak's TMX data sheet, it says that normal development
time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i can not understand this. |
#2
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pushing time shorter than normal time?
"Steven Woody" wrote in message ps.com... i noticed in Kodak's TMX data sheet, it says that normal development time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i can not understand this. Which data sheet is this? I am looking at F-4016 January 2002 which is I think the current one. It gives 6-1/2 minutes for both speeds, small tank, 68F. This is in line with Kodak's claim that T-Max films can be underexposed one stop wtih no adjustment in developing time. I see 7-1/4 minutes at 68F using D-76 for large tank processing of T-Max 100 at normal speed but the push processing charts for large tanks do not show D-76 at all. Check the data sheet for its number and date, I have some of the older ones too, and also tell me which charts you are getting the data from. Note that Kodak has made misprints in the past. -- --- Richard Knoppow Los Angeles, CA, USA |
#3
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pushing time shorter than normal time?
"Steven Woody" wrote in message oups.com... Richard Knoppow wrote: "Steven Woody" wrote in message ps.com... i noticed in Kodak's TMX data sheet, it says that normal development time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i can not understand this. Which data sheet is this? I am looking at F-4016 January 2002 which is I think the current one. It gives 6-1/2 minutes for both speeds, small tank, 68F. This is in line with Kodak's claim that T-Max films can be underexposed one stop wtih no adjustment in developing time. I see 7-1/4 minutes at 68F using D-76 for large tank processing of T-Max 100 at normal speed but the push processing charts for large tanks do not show D-76 at all. Check the data sheet for its number and date, I have some of the older ones too, and also tell me which charts you are getting the data from. Note that Kodak has made misprints in the past. that doc i mentioned is in my office and i can not touch it now. but i just checked the F-4016 in my home computer, i found the devlopment time in the doc are all 9 mins for normal speed and EI200 pushing, it still differ with what you said. this version is F-4016, March 2002. - woody Are you sure you have F-4016 and not F-32? The 9 minute time is given in F-32, which is the data brochure for the old T-Max, the web version is dated March 2002 because of a notice of the discontinuance of the film. The latest edition of F-4016 is dated February 2002. I am not sure what revisions were made to the edition I had but the times for the new T-Max are the same. A change from 9 minutes to 6-1/2 minutes is substantial. Rumor is that the overcoating of the film was changed. The original T-Max 100 and T-Max 400 were designed to have very similar development times so that they could be processed together. This is not true of the current films. The overcoating has an effect on the induction time, that is, the time between immersion the film in the developer and the first appearance of the image. In any case, the times for one stop pushing are the same as for normal processing. -- --- Richard Knoppow Los Angeles, CA, USA |
#4
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pushing time shorter than normal time?
"Steven Woody" wrote in message ups.com... Richard Knoppow wrote: "Steven Woody" wrote in message oups.com... Richard Knoppow wrote: "Steven Woody" wrote in message ps.com... i noticed in Kodak's TMX data sheet, it says that normal development time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i can not understand this. Which data sheet is this? I am looking at F-4016 January 2002 which is I think the current one. It gives 6-1/2 minutes for both speeds, small tank, 68F. This is in line with Kodak's claim that T-Max films can be underexposed one stop wtih no adjustment in developing time. I see 7-1/4 minutes at 68F using D-76 for large tank processing of T-Max 100 at normal speed but the push processing charts for large tanks do not show D-76 at all. Check the data sheet for its number and date, I have some of the older ones too, and also tell me which charts you are getting the data from. Note that Kodak has made misprints in the past. that doc i mentioned is in my office and i can not touch it now. but i just checked the F-4016 in my home computer, i found the devlopment time in the doc are all 9 mins for normal speed and EI200 pushing, it still differ with what you said. this version is F-4016, March 2002. - woody Are you sure you have F-4016 and not F-32? The 9 minute time is given in F-32, which is the data brochure for the old T-Max, the web version is dated March 2002 because of a notice of the discontinuance of the film. The latest edition of F-4016 is dated February 2002. I am not sure what revisions were made to the edition I had but the times for the new T-Max are the same. A change from 9 minutes to 6-1/2 minutes is substantial. Rumor is that the overcoating of the film was changed. The original T-Max 100 and T-Max 400 were designed to have very similar development times so that they could be processed together. This is not true of the current films. The overcoating has an effect on the induction time, that is, the time between immersion the film in the developer and the first appearance of the image. In any case, the times for one stop pushing are the same as for normal processing. -- --- Richard Knoppow Los Angeles, CA, USA many thanks to you. i think i was using F-32 for development of my T-MAX. it is amazing the those nagatives still show images :-) actually, i've been using 12 mins in D-76 1:1, that should be 9 1/2 instead. another question is, Kodak not list pushing time for D-76 1:1, how can i get know of it? i think, from EI100 to EI200, the time is no change for D-76, so do D-76 1:1 ( 9 1/2 mins ); from E1100 to EI400, the time changed to 8 1/4 mins which is 27% longer for D-76, so do D-76 1:1 ( 9 1/2 * 1.27 = 12 mins ). am i right? thanks. - woody I use D-76 1:1 for T-Max routinely because I prefer the longer development times. I think for EI 200 I would follow the instructions for other developers, that is, no change from normal development. As a rule of thumb a one stop push requires about 1.5 times the "normal" time but I've seen Kodak instructions that suggest less. perhaps 30% increase. Beware that increasing development time does not really increase speed. It only increases contrast but the toe region of the characteristic curve, where the low exposure part of the image is, is also increased in contrast, which may make the images easier to print. The downside is that the contrast of the more normally exposed parts of the image will become very contrasty. Where you must push film the ideal lighting is pretty flat, however, one can not often choose in available light situations. Using a Phenidone developer will give you about 3/4 stop greater speed for the same contrast. They are better push developers than D-76. Among them are Kodak T-Max and T-Max RS, Xtol, Ilford Microphen, formula ID-68, and DDX, and a few others. With the exception of Xtol these all produce slightly coarser grain than D-76. Xtol is pretty close to being an optimum developer for many purposes but has proven to be somewhat unreliable. Ryuji Suzuki, a biological chemist, has done considerable research into developers and emulsions. Some of it is detailed on his web site at http://www.silvergrain.org. He has formulated a developer similar to Xtol but with some attention to curing Xtol's short time failure problem. It is now being put up commercially by Photographer's Formulary, details are on his web site. -- --- Richard Knoppow Los Angeles, CA, USA |
#5
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pushing time shorter than normal time?
"Steven Woody" wrote in message ups.com... Richard Knoppow wrote: "Steven Woody" wrote in message oups.com... Richard Knoppow wrote: "Steven Woody" wrote in message ps.com... i noticed in Kodak's TMX data sheet, it says that normal development time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i can not understand this. A correction: I am not sure if Ryuji Suzuki's film developer is available commercially yet. He has some paper developers which are. The formula for his film developer is on his web site. http://www.silvergrain.org You will have to do some poking around to find it. -- --- Richard Knoppow Los Angeles, CA, USA |
#6
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pushing time shorter than normal time?
Richard Knoppow wrote: "Steven Woody" wrote in message ups.com... Richard Knoppow wrote: "Steven Woody" wrote in message oups.com... Richard Knoppow wrote: "Steven Woody" wrote in message ps.com... i noticed in Kodak's TMX data sheet, it says that normal development time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i can not understand this. Which data sheet is this? I am looking at F-4016 January 2002 which is I think the current one. It gives 6-1/2 minutes for both speeds, small tank, 68F. This is in line with Kodak's claim that T-Max films can be underexposed one stop wtih no adjustment in developing time. I see 7-1/4 minutes at 68F using D-76 for large tank processing of T-Max 100 at normal speed but the push processing charts for large tanks do not show D-76 at all. Check the data sheet for its number and date, I have some of the older ones too, and also tell me which charts you are getting the data from. Note that Kodak has made misprints in the past. that doc i mentioned is in my office and i can not touch it now. but i just checked the F-4016 in my home computer, i found the devlopment time in the doc are all 9 mins for normal speed and EI200 pushing, it still differ with what you said. this version is F-4016, March 2002. - woody Are you sure you have F-4016 and not F-32? The 9 minute time is given in F-32, which is the data brochure for the old T-Max, the web version is dated March 2002 because of a notice of the discontinuance of the film. The latest edition of F-4016 is dated February 2002. I am not sure what revisions were made to the edition I had but the times for the new T-Max are the same. A change from 9 minutes to 6-1/2 minutes is substantial. Rumor is that the overcoating of the film was changed. The original T-Max 100 and T-Max 400 were designed to have very similar development times so that they could be processed together. This is not true of the current films. The overcoating has an effect on the induction time, that is, the time between immersion the film in the developer and the first appearance of the image. In any case, the times for one stop pushing are the same as for normal processing. -- --- Richard Knoppow Los Angeles, CA, USA many thanks to you. i think i was using F-32 for development of my T-MAX. it is amazing the those nagatives still show images :-) actually, i've been using 12 mins in D-76 1:1, that should be 9 1/2 instead. another question is, Kodak not list pushing time for D-76 1:1, how can i get know of it? i think, from EI100 to EI200, the time is no change for D-76, so do D-76 1:1 ( 9 1/2 mins ); from E1100 to EI400, the time changed to 8 1/4 mins which is 27% longer for D-76, so do D-76 1:1 ( 9 1/2 * 1.27 = 12 mins ). am i right? thanks. - woody I use D-76 1:1 for T-Max routinely because I prefer the longer development times. I think for EI 200 I would follow the instructions for other developers, that is, no change from normal development. As a rule of thumb a one stop push requires about 1.5 times the "normal" time but I've seen Kodak instructions that suggest less. perhaps 30% increase. Beware that increasing development time does not really increase speed. It only increases contrast but the toe region of the characteristic curve, where the low exposure part of the image is, is also increased in contrast, which may make the images easier to print. The downside is that the contrast of the more normally exposed parts of the image will become very contrasty. Where you must push film the ideal lighting is pretty flat, however, one can not often choose in available light situations. Using a Phenidone developer will give you about 3/4 stop greater speed for the same contrast. They are better push developers than D-76. Among them are Kodak T-Max and T-Max RS, Xtol, Ilford Microphen, formula ID-68, and DDX, and a few others. With the exception of Xtol these all produce slightly coarser grain than D-76. Xtol is pretty close to being an optimum developer for many purposes but has proven to be somewhat unreliable. Ryuji Suzuki, a biological chemist, has done considerable research into developers and emulsions. Some of it is detailed on his web site at http://www.silvergrain.org. He has formulated a developer similar to Xtol but with some attention to curing Xtol's short time failure problem. It is now being put up commercially by Photographer's Formulary, details are on his web site. -- --- Richard Knoppow Los Angeles, CA, USA thanks for your information! |
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