| Page 1 of 2 | 1 | 2 |
|
|
|
Reducing fog in expired film
I have a bunch of long expired film that I'm working on developing. To keep things simple I'm using D76 diluted 1:1 and am
having problems with fogging. I know that Benzotriazol should help and that Potasium Bromide may help. Does anyone have experience with either approach or have other suggestions? I'm also interested in home much much I can add to the stock D76. -- ------------------- Keep working dumbo needs the money |
Reducing fog in expired film
Richard Knoppow wrote:
: On Jan 30, 5:57??pm, Frank Pittel wrote: : I have a bunch of long expired film that I'm working on developing. To keep things simple I'm using D76 diluted 1:1 and am : having problems with fogging. I know that Benzotriazol should help and that Potasium Bromide may help. Does anyone : have experience with either approach or have other suggestions? I'm also interested in home much much I can add to : the stock D76. : : -- : : ------------------- : Keep working dumbo needs the money : There is a chart showing benzotriazole use in _Modern : Photographic Processing_ by Grant Haist. However, fog in negatives may : look bad but for the most part just increases printing time a bit, : provided its uniform. The film should be given a bit more exposure : than if it was fog free. Increasing development will increase the fog : along with the contrast so is not useful. Bromide will also reduce : fog. It seems to have more effect on film speed than benzotriazole, : the remarks above apply to it also. : I have been able to get rid of moderate age fog on Plus-X sheet : film by adding about 1 gram/liter to D-76 1:1. I shot the film at : about half the rated speed. The unexposed margins were pretty clear. : The prints were not any better than similarly exposed film developed : without the added bromide. Richard, Thanks for the quick reply. If the film were unexposed I would pitch and get "fresh" film. Alas, the film was exposed anywhere from 20 to 40 years ago and there's no date on the rolls. There's a lot of fog and it seems to be hurting the shadow contrast. To get any kind of reasonable print we and the others working on the project are being forced to do a lot of printing with two (or in some cases three) filters. One of the filters generally being a #5 so we get some contrast in the shadows after using a 2-3.5 filter for the main exposure. My hope is that by reducing the fog we would pick up the contrast in the shadow. With minor exceptions the fog is uniform and "printing through the fog" is working alright. Frank BTW - I ordered the Haist books a few days prior to my original post and have since recieved it. For those that haven't seen or read it Grant Haist is an amazing talent and I wish I got the books years ago!! -- ------------------- Keep working dumbo needs the money |
Reducing fog in expired film
On 2/2/2011 23:53 PM, Frank Pittel wrote:
Richard wrote: : On Jan 30, 5:57??pm, Frank wrote: : I have a bunch of long expired film that I'm working on developing. To keep things simple I'm using D76 diluted 1:1 and am : having problems with fogging. I know that Benzotriazol should help and that Potasium Bromide may help. Does anyone : have experience with either approach or have other suggestions? I'm also interested in home much much I can add to : the stock D76. : : -- : : ------------------- : Keep working dumbo needs the money : There is a chart showing benzotriazole use in _Modern : Photographic Processing_ by Grant Haist. However, fog in negatives may : look bad but for the most part just increases printing time a bit, : provided its uniform. The film should be given a bit more exposure : than if it was fog free. Increasing development will increase the fog : along with the contrast so is not useful. Bromide will also reduce : fog. It seems to have more effect on film speed than benzotriazole, : the remarks above apply to it also. : I have been able to get rid of moderate age fog on Plus-X sheet : film by adding about 1 gram/liter to D-76 1:1. I shot the film at : about half the rated speed. The unexposed margins were pretty clear. : The prints were not any better than similarly exposed film developed : without the added bromide. Richard, Thanks for the quick reply. If the film were unexposed I would pitch and get "fresh" film. Alas, the film was exposed anywhere from 20 to 40 years ago and there's no date on the rolls. There's a lot of fog and it seems to be hurting the shadow contrast. To get any kind of reasonable print we and the others working on the project are being forced to do a lot of printing with two (or in some cases three) filters. One of the filters generally being a #5 so we get some contrast in the shadows after using a 2-3.5 filter for the main exposure. My hope is that by reducing the fog we would pick up the contrast in the shadow. With minor exceptions the fog is uniform and "printing through the fog" is working alright. Frank BTW - I ordered the Haist books a few days prior to my original post and have since recieved it. For those that haven't seen or read it Grant Haist is an amazing talent and I wish I got the books years ago!! Some years ago, the founder of Film Rescue International (see http://www.filmrescue.com/ ) used to participate in this forum. He had, through long trial and error - together with a good knowledge of photochemistry - put together a process for minimizing film in such situations. If top quality recovery is your objective, you may want to contact Film Rescue. He shared some information with me at a time when I was trying to develop some 80 year old negatives (Richard probably recalls that trial), but I promised I would not reveal his proprietary information. And, I have to confess, I lost the specific email he sent, and only have fragmentary information now anyway. I also note that the following is a patent filed in 1966 (now in the public domain) which describes a method of fog reduction in silver halide films. http://www.freepatentsonline.com/3244522.pdf Attention should be paid not just to the particular forms of xylene or benzene to be used, but also to the specific development processes described. -- Francis A. Miniter In dem Lande der Pygmäen gibt es keine Uniformen, weder Abzeichen, noch irgend welche Normen, Und Soldaten sind dort nicht zu sehen. Siegfried von Vegesack, "Es gibt keine Uniformen" from In dem Lande der Pygmäen |
Reducing fog in expired film
On 2/7/2011 16:04 PM, Francis A. Miniter wrote:
On 2/2/2011 23:53 PM, Frank Pittel wrote: Richard wrote: : On Jan 30, 5:57??pm, Frank wrote: : I have a bunch of long expired film that I'm working on developing. To keep things simple I'm using D76 diluted 1:1 and am : having problems with fogging. I know that Benzotriazol should help and that Potasium Bromide may help. Does anyone : have experience with either approach or have other suggestions? I'm also interested in home much much I can add to : the stock D76. : : -- : : ------------------- : Keep working dumbo needs the money : There is a chart showing benzotriazole use in _Modern : Photographic Processing_ by Grant Haist. However, fog in negatives may : look bad but for the most part just increases printing time a bit, : provided its uniform. The film should be given a bit more exposure : than if it was fog free. Increasing development will increase the fog : along with the contrast so is not useful. Bromide will also reduce : fog. It seems to have more effect on film speed than benzotriazole, : the remarks above apply to it also. : I have been able to get rid of moderate age fog on Plus-X sheet : film by adding about 1 gram/liter to D-76 1:1. I shot the film at : about half the rated speed. The unexposed margins were pretty clear. : The prints were not any better than similarly exposed film developed : without the added bromide. Richard, Thanks for the quick reply. If the film were unexposed I would pitch and get "fresh" film. Alas, the film was exposed anywhere from 20 to 40 years ago and there's no date on the rolls. There's a lot of fog and it seems to be hurting the shadow contrast. To get any kind of reasonable print we and the others working on the project are being forced to do a lot of printing with two (or in some cases three) filters. One of the filters generally being a #5 so we get some contrast in the shadows after using a 2-3.5 filter for the main exposure. My hope is that by reducing the fog we would pick up the contrast in the shadow. With minor exceptions the fog is uniform and "printing through the fog" is working alright. Frank BTW - I ordered the Haist books a few days prior to my original post and have since recieved it. For those that haven't seen or read it Grant Haist is an amazing talent and I wish I got the books years ago!! Some years ago, the founder of Film Rescue International (see http://www.filmrescue.com/ ) used to participate in this forum. He had, through long trial and error - together with a good knowledge of photochemistry - put together a process for minimizing film in such situations. If top quality recovery is your objective, you may want to contact Film Rescue. He shared some information with me at a time when I was trying to develop some 80 year old negatives (Richard probably recalls that trial), but I promised I would not reveal his proprietary information. And, I have to confess, I lost the specific email he sent, and only have fragmentary information now anyway. I also note that the following is a patent filed in 1966 (now in the public domain) which describes a method of fog reduction in silver halide films. http://www.freepatentsonline.com/3244522.pdf Attention should be paid not just to the particular forms of xylene or benzene to be used, but also to the specific development processes described. Here is another relevant patent in the public domain. Again, note the details that the two processes have in common: http://www.freepatentsonline.com/3226232.pdf -- Francis A. Miniter In dem Lande der Pygmäen gibt es keine Uniformen, weder Abzeichen, noch irgend welche Normen, Und Soldaten sind dort nicht zu sehen. Siegfried von Vegesack, "Es gibt keine Uniformen" from In dem Lande der Pygmäen |
Quote:
|
Reducing fog in expired film
"Francis A. Miniter" wrote in message ... On 2/7/2011 16:04 PM, Francis A. Miniter wrote: On 2/2/2011 23:53 PM, Frank Pittel wrote: Richard wrote: : On Jan 30, 5:57??pm, Frank wrote: : I have a bunch of long expired film that I'm working on developing. To keep things simple I'm using D76 diluted 1:1 and am : having problems with fogging. I know that Benzotriazol should help and that Potasium Bromide may help. Does anyone : have experience with either approach or have other suggestions? I'm also interested in home much much I can add to : the stock D76. : : -- : : ------------------- : Keep working dumbo needs the money : There is a chart showing benzotriazole use in _Modern : Photographic Processing_ by Grant Haist. However, fog in negatives may : look bad but for the most part just increases printing time a bit, : provided its uniform. The film should be given a bit more exposure : than if it was fog free. Increasing development will increase the fog : along with the contrast so is not useful. Bromide will also reduce : fog. It seems to have more effect on film speed than benzotriazole, : the remarks above apply to it also. : I have been able to get rid of moderate age fog on Plus-X sheet : film by adding about 1 gram/liter to D-76 1:1. I shot the film at : about half the rated speed. The unexposed margins were pretty clear. : The prints were not any better than similarly exposed film developed : without the added bromide. Richard, Thanks for the quick reply. If the film were unexposed I would pitch and get "fresh" film. Alas, the film was exposed anywhere from 20 to 40 years ago and there's no date on the rolls. There's a lot of fog and it seems to be hurting the shadow contrast. To get any kind of reasonable print we and the others working on the project are being forced to do a lot of printing with two (or in some cases three) filters. One of the filters generally being a #5 so we get some contrast in the shadows after using a 2-3.5 filter for the main exposure. My hope is that by reducing the fog we would pick up the contrast in the shadow. With minor exceptions the fog is uniform and "printing through the fog" is working alright. Frank BTW - I ordered the Haist books a few days prior to my original post and have since recieved it. For those that haven't seen or read it Grant Haist is an amazing talent and I wish I got the books years ago!! Some years ago, the founder of Film Rescue International (see http://www.filmrescue.com/ ) used to participate in this forum. He had, through long trial and error - together with a good knowledge of photochemistry - put together a process for minimizing film in such situations. If top quality recovery is your objective, you may want to contact Film Rescue. He shared some information with me at a time when I was trying to develop some 80 year old negatives (Richard probably recalls that trial), but I promised I would not reveal his proprietary information. And, I have to confess, I lost the specific email he sent, and only have fragmentary information now anyway. I also note that the following is a patent filed in 1966 (now in the public domain) which describes a method of fog reduction in silver halide films. http://www.freepatentsonline.com/3244522.pdf Attention should be paid not just to the particular forms of xylene or benzene to be used, but also to the specific development processes described. Here is another relevant patent in the public domain. Again, note the details that the two processes have in common: http://www.freepatentsonline.com/3226232.pdf -- Francis A. Miniter Its good to see you are still here Francis. I do remember the thread. I also talked to the guy. He gave me some hints but not the actual process. We talked enough to convince me that he knows what he is doing. A good source for patents is Google Patents. One can do a complete text search on all US patents ever issued and download them as PDF's, much more convenient than the Fax TIFF files from the USPTO. -- -- Richard Knoppow Los Angeles, CA, USA |
Reducing fog in expired film
Richard Knoppow wrote:
: "Frank Pittel" wrote in : message : ... : Richard Knoppow wrote: : : On Jan 30, 5:57??pm, Frank Pittel : wrote: : : I have a bunch of long expired film that I'm working : on developing. To keep things simple I'm using D76 diluted : 1:1 and am : : having problems with fogging. I know that Benzotriazol : should help and that Potasium Bromide may help. Does : anyone : : have experience with either approach or have other : suggestions? I'm also interested in home much much I can : add to : : the stock D76. : : : : -- : : : : ------------------- : : Keep working dumbo needs the money : : : There is a chart showing benzotriazole use in : _Modern : : Photographic Processing_ by Grant Haist. However, fog in : negatives may : : look bad but for the most part just increases printing : time a bit, : : provided its uniform. The film should be given a bit : more exposure : : than if it was fog free. Increasing development will : increase the fog : : along with the contrast so is not useful. Bromide will : also reduce : : fog. It seems to have more effect on film speed than : benzotriazole, : : the remarks above apply to it also. : : I have been able to get rid of moderate age fog on : Plus-X sheet : : film by adding about 1 gram/liter to D-76 1:1. I shot : the film at : : about half the rated speed. The unexposed margins were : pretty clear. : : The prints were not any better than similarly exposed : film developed : : without the added bromide. : : Richard, : : Thanks for the quick reply. If the film were unexposed I : would pitch and get : "fresh" film. Alas, the film was exposed anywhere from 20 : to 40 years ago and : there's no date on the rolls. There's a lot of fog and it : seems to be hurting : the shadow contrast. To get any kind of reasonable print : we and the others : working on the project are being forced to do a lot of : printing with two (or : in some cases three) filters. One of the filters generally : being a #5 so we get : some contrast in the shadows after using a 2-3.5 filter : for the main exposure. : My hope is that by reducing the fog we would pick up the : contrast in the shadow. : With minor exceptions the fog is uniform and "printing : through the fog" is : working alright. : : Frank : : BTW - I ordered the Haist books a few days prior to my : original post and have since : recieved it. For those that haven't seen or read it Grant : Haist is an amazing : talent and I wish I got the books years ago!! : : Grant reprinted his large book some years ago, very : high quality job. I talked to him a couple of times then via : phone. It was the last gasp of a comprehensive book on : photographic processes and chemistry. Grant also wrote a : smaller book on monobath processing which is very : interesting. Monobaths are nearly forgotten but have some : advantages over conventional processing. He discusses them : to some extent in _Modern Photoraphic Processes_ but the : small book goes into much more detail. : Grant was a scientist working for Kodak Research Labs. : I don't know if he is still alive, he was pretty old when I : got my books perhaps ten years ago now. I got the books and based on the contents of the books I was able to convince the people running the development project to try adding some benzotriazol to the D76 they're using. While the potassium bromide also helped it reduced the overall contrast and it was decided not to use it. The benzotriazol has helped and is improving the shadow contrast and is resulting in negative much easier to print. I've got a couple of photographic projects/testing that are high up on the list but I'd like to give monobath developers a try. No good reason but it sounds cool! :-) I wish there some good books about prints and developers for them! -- ------------------- Keep working dumbo needs the money |
Reducing fog in expired film
On 25 Feb 2011 in rec.photo.darkroom, Frank Pittel wrote:
I wish there some good books about prints and developers for them! Ansel Adams, 'The Print'? http://www.amazon.com/Print-Ansel-Ad.../dp/0821221876 -- Joe Makowiec http://makowiec.org/ Email: http://makowiec.org/contact/?Joe Usenet Improvement Project: http://twovoyagers.com/improve-usenet.org/ |
Reducing fog in expired film
Joe Makowiec wrote:
: On 25 Feb 2011 in rec.photo.darkroom, Frank Pittel wrote: : I wish there some good books about prints and developers for them! : Ansel Adams, 'The Print'? : http://www.amazon.com/Print-Ansel-Ad.../dp/0821221876 A very good book and I enjoyed reading the copy I have. I'm thinking more in terms of books like the Film Developers Cookbook and Modern Photographic Processing. Although most of what's in Modern Photographic Processing applies to paper as well as film. -- ------------------- Keep working dumbo needs the money |
| All times are GMT +1. The time now is 03:32 AM. |
|
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
PhotoBanter.com