If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Prewarming film emulsion
Recently, while inquiring about E-6 kits at my local camera store, one of
the co-owners (brothers) described one of the kits, Tetenal, I think. Reading from a product description, he said that particular kit required one to "prewarm" the emulsion, presumably using warm water at 104 degress Fahrenheit. This got me to thinking: Could one use a similar approach with B&W? While I'm not sure how it would affect development times, softening the emulsion may enable the developer to do its work. (However, I should note that it's been some time since I developed ANY film.) Dieter Zakas -- Good, better, best; never let it rest, until your good is better and your better is best. (Billy Cox) |
#2
|
|||
|
|||
Prewarming film emulsion
On Fri, 25 Nov 2005 21:06:15 -0600, Dieter Zakas
wrote: Recently, while inquiring about E-6 kits at my local camera store, one of the co-owners (brothers) described one of the kits, Tetenal, I think. Reading from a product description, he said that particular kit required one to "prewarm" the emulsion, presumably using warm water at 104 degress Fahrenheit. This got me to thinking: Could one use a similar approach with B&W? While I'm not sure how it would affect development times, softening the emulsion may enable the developer to do its work. (However, I should note that it's been some time since I developed ANY film.) Most if not all manufacturers recommend that you do not "prewet" the films prior to development as the water in the emulsion may impede develoment progress and uneven development is theoretically possible. Note that I've never heard of such a case. The other reason that don't recommend the practice is that the rinse tends to rinse out the wetting agent that is included in the film. -- Regards, John S. Douglas, Photographer & Webmaster http://www.puresilver.org - http://www.legacy-photo.com |
#3
|
|||
|
|||
Prewarming film emulsion
John spake thus:
On Fri, 25 Nov 2005 21:06:15 -0600, Dieter Zakas wrote: Recently, while inquiring about E-6 kits at my local camera store, one of the co-owners (brothers) described one of the kits, Tetenal, I think. Reading from a product description, he said that particular kit required one to "prewarm" the emulsion, presumably using warm water at 104 degress Fahrenheit. This got me to thinking: Could one use a similar approach with B&W? While I'm not sure how it would affect development times, softening the emulsion may enable the developer to do its work. (However, I should note that it's been some time since I developed ANY film.) Most if not all manufacturers recommend that you do not "prewet" the films prior to development as the water in the emulsion may impede develoment progress and uneven development is theoretically possible. Note that I've never heard of such a case. The other reason that don't recommend the practice is that the rinse tends to rinse out the wetting agent that is included in the film. So what difference would that make? Once the film is wet, why would you need wetting agent? -- .... asked to comment on Michigan governor George Romney's remark that the army had "brainwashed" him in Vietnam—-a remark which knocked Romney out of the running for the Republican nomination—-McCarthy quipped, "I think in that case a light rinse would have been sufficient." (Eugene McCarthy, onetime candidate for POTUS) |
#4
|
|||
|
|||
Prewarming film emulsion
Phototherm's black and white programs prewet the film and Jobo has in the
past (and may still) recommend a five minute prewash when processing black and white. Since the temperature that black and white is normally processed at is only a little above room temp the pre-wet is not so much for tempering as it is for evenness of development. I currently use a Unicolor Film Drum and motor base and use a five minute prewash. I have tried shorter presoaks and with some combinations of film and developer got less than ideal results. If you are going to use a presoak with black and white stick with 5 minutes. (At least until you can test and come up with a shorter standard minimum time that works with all the combinations and permutations of film type, developer type, temperature and agitation that you will use in your own work!) -- darkroommike ---------- "Dieter Zakas" wrote in message ... Recently, while inquiring about E-6 kits at my local camera store, one of the co-owners (brothers) described one of the kits, Tetenal, I think. Reading from a product description, he said that particular kit required one to "prewarm" the emulsion, presumably using warm water at 104 degress Fahrenheit. This got me to thinking: Could one use a similar approach with B&W? While I'm not sure how it would affect development times, softening the emulsion may enable the developer to do its work. (However, I should note that it's been some time since I developed ANY film.) Dieter Zakas -- Good, better, best; never let it rest, until your good is better and your better is best. (Billy Cox) |
#5
|
|||
|
|||
Prewarming film emulsion
Dieter Zakas a écrit :
Recently, while inquiring about E-6 kits at my local camera store, one of the co-owners (brothers) described one of the kits, Tetenal, I think. Reading from a product description, he said that particular kit required one to "prewarm" the emulsion, presumably using warm water at 104 degress Fahrenheit. This got me to thinking: Could one use a similar approach with B&W? While I'm not sure how it would affect development times, softening the emulsion may enable the developer to do its work. (However, I should note that it's been some time since I developed ANY film.) Dieter Zakas E-6 pre-warming is usually done *without* water, often during 5' to warm up the tank/reel/film before 1st developer in which temperature is critical. For B/W, both schools exist: pre-wetting or not. Pre-wetting can be useful for short development times and reduces the risk of developer streaks with larger formats. You have to adapt your development time. Personally I don't feel the need to pre-wet ... Best regards, Claudio Bonavolta http://www.bonavolta.ch |
#6
|
|||
|
|||
Prewarming film emulsion
In article op.s0t09xxpuvfup0@jd, John wrote:
The other reason that don't recommend the practice is that the rinse tends to rinse out the wetting agent that is included in the film. If that's the case how would the other three solutions fail to wash out the wetting agent/ or do you mean there is wetting agent incorporated to make the initial developer evenly coat the film? Btw I have never added wetting agent to any film prior to the final rinse. -- "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 www.gregblankphoto(dot)com |
#7
|
|||
|
|||
Prewarming film emulsion
In article ,
Dieter Zakas wrote: Recently, while inquiring about E-6 kits at my local camera store, one of the co-owners (brothers) described one of the kits, Tetenal, I think. Reading from a product description, he said that particular kit required one to "prewarm" the emulsion, presumably using warm water at 104 degress Fahrenheit. Well unless it states prewarming is done with water as a prewet, it is an assumption. Not always good to assume! This got me to thinking: Could one use a similar approach with B&W? While I'm not sure how it would affect development times, softening the emulsion may enable the developer to do its work. (However, I should note that it's been some time since I developed ANY film.) Here's my take: you'll get as many answers as practitioners, but prewetting 5 minutes seems excessive, however 5 minutes prewarming is probably correct, you do want to have the film-reel and tank at the process temperature. By prewarming your insuring the times are accurate for development, because times are established (hopefully) without lag time factored as an unknown. Any time the film etc must come up to the process temp -lag time exists. I typically do prewash my large format film, ONE/TWO minutes only....I feel it washes out the back anti reflection coating and does warm the film up more quickly....I have never had problems but I bidirectionally rotate or rock my drum drums during process. I am quite sure there are many correct answers to your question as the process can take a lot of variation and still yield VG results. -- "To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public."--Theodore Roosevelt, May 7, 1918 www.gregblankphoto(dot)com |
#8
|
|||
|
|||
Prewarming film emulsion
On Fri, 25 Nov 2005 23:23:47 -0600, John
wrote: Most if not all manufacturers recommend that you do not "prewet" the films prior to development as the water in the emulsion may impede develoment progress and uneven development is theoretically possible. Note that I've never heard of such a case. The other reason that don't recommend the practice is that the rinse tends to rinse out the wetting agent that is included in the film. November 26, 2005, from Lloyd Erlick, And here I've been pre-soaking my film before the developer for lo these many years ... oh, well, wrong again. regards, --le ________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: net: www.heylloyd.com ________________________________ -- |
#9
|
|||
|
|||
Prewarming film emulsion
Lloyd Erlick spake thus:
On Fri, 25 Nov 2005 23:23:47 -0600, John wrote: Most if not all manufacturers recommend that you do not "prewet" the films prior to development as the water in the emulsion may impede develoment progress and uneven development is theoretically possible. Note that I've never heard of such a case. The other reason that don't recommend the practice is that the rinse tends to rinse out the wetting agent that is included in the film. And here I've been pre-soaking my film before the developer for lo these many years ... oh, well, wrong again. I wouldn't say "wrong"; it's hard to see how a presoak could have any ill effects, like uneven development. Seems to me it would have quite the opposite effect, as the emulsion is thoroughly wet and the chemistry can more easily diffuse through it. Wonder what Richard K. has to say about this. -- .... asked to comment on Michigan governor George Romney's remark that the army had "brainwashed" him in Vietnam—-a remark which knocked Romney out of the running for the Republican nomination—-McCarthy quipped, "I think in that case a light rinse would have been sufficient." (Eugene McCarthy, onetime candidate for POTUS) |
#10
|
|||
|
|||
Prewarming film emulsion
On Sat, 26 Nov 2005 06:50:36 -0600, Gregory Blank
wrote: In article op.s0t09xxpuvfup0@jd, John wrote: The other reason that don't recommend the practice is that the rinse tends to rinse out the wetting agent that is included in the film. If that's the case how would the other three solutions fail to wash out the wetting agent/ or do you mean there is wetting agent incorporated to make the initial developer evenly coat the film? I believe that it is included in the emulsion during the coating. -- Regards, John S. Douglas, Photographer & Webmaster http://www.puresilver.org - http://www.legacy-photo.com |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
is it a forgone conclusion... | Robert S. Dean | In The Darkroom | 123 | March 18th 05 04:15 AM |
8Mp Digital The Theoretical 35mm Quality Equivelant | Matt | Digital Photography | 1144 | December 17th 04 09:48 PM |
Are Paper Speeds Slow Due to the Thin Emulsion? | Dan Quinn | In The Darkroom | 74 | August 18th 04 11:26 PM |
Insane new TSA rule for film inspection | [email protected] | 35mm Photo Equipment | 94 | June 23rd 04 05:17 AM |
The first film of the Digital Revolution is here.... | Todd Bailey | Film & Labs | 0 | May 27th 04 08:12 AM |