Luis-F-S
Member
I develop 8x-10 sheets in Unicolor drums and give two 1 minute prewashes all at 68 deg F
I had many private conversations with PE about prewash. I prewash all film except Tri-X 400 when developed with XTOL in a Jobo processor. Both Kodak and Jobo agree with that. Especially when using replenished developer, prewash get rid of the blue dye.
I never read about prewash, before joining Apug.I've read a lot about pre-wash.
I think the first time I heard it was in the 1980’s when reading Adam’s “The Negative”. At least I think it was that book.I never read about prewash, before joining Apug.
I never read about prewash, before joining Apug.
I think the first time I heard it was in the 1980’s when reading Adam’s “The Negative”. At least I think it was that book.
Isn't necessary at all.I've read a lot about pre-wash and would like to give it a go but can't find anything regarding the actual process.
1. Tap water or de-ionised.
2. Length of time.
3. Agitation.
Greatly appreciate many of you may think it's unnecessary but equally there are those that do. I'd just like to try it for myself. Experimenting's always the best way, after all.
I've read a lot about pre-wash and would like to give it a go but can't find anything regarding the actual process.
1. Tap water or de-ionised.
2. Length of time.
3. Agitation.
Greatly appreciate many of you may think it's unnecessary but equally there are those that do. I'd just like to try it for myself. Experimenting's always the best way, after all.
If your prewash removed those, then your film is totally wet and you don't need them anymore......
The reason why pre-wash is not required is that modern emulsions include surfactants to promote a fast and even wetting, if you pre-wash ilford film then you remove those benefical surfactants from the emulsion and this may lead to an uneven development is pre-wash is too short.....
The reason why pre-wash is not required is that modern emulsions include surfactants to promote a fast and even wetting, if you pre-wash ilford film then you remove those benefical surfactants from the emulsion and this may lead to an uneven development is pre-wash is too short.
Once wetted there will be access for all baths during processing. Following your idea one would need a surfactant added before each step.
Surfactant are built in in some films, Ilford uses them. If Ilford uses them I'm confident they use for a reason.PE discussed this many times. He recommended prewash for most films with a few cases that he pointed out not to Feel free to look through his posts. Prewash is used to bring the film to temperature and provide even absorption of chemicals. He specifically stated not to use surfactants for that purpose.
PE discussed this many times. He recommended prewash for most films with a few cases that he pointed out not to Feel free to look through his posts. Prewash is used to bring the film to temperature and provide even absorption of chemicals. He specifically stated not to use surfactants for that purpose.
Surfactant are built in in some films, Ilford uses them. If Ilford uses them I'm confident they use for a reason.
I am assuming that manufacturers do not use what is not needed, it would be an avoidable cost.
It's also written black on white in the HP5+ tecnhical sheet, as reported above.
Once wetted there will be access for all baths during processing. Following your idea one would need a surfactant added before each step.
Of course it's not advisabe to add any surfactant to the developer, since the film emulsion has some already built in, as said before, although, to remain in this thread, the original topic was on the use of the prewash, which is imho not advisabe at all.The discussion was adding surfactants, not the ones in the products. Look at PE's posts and other than the final rinse for film, he rarely recommends adding surfactants.
Of course it's not advisabe to add any surfactant to the developer, since the film emulsion has some already built in, as said before, although, to remain in this thread, the original topic was on the use of the prewash, which is imho not advisabe at all.
You're free to follow what suits you the most.Take the time to read PE's posts. He disagree with you and he had the background to evaluate the subject. Again read PE's posts. For myself, I found an improvement on the films that I prewash. There is one film that I do not prewash as I stated. You are free to disagree, but I choose to follow PE's advice and experience.
No! The STOP BATH is the KEY.
If your prewash removed those, then your film is totally wet and you don't need them anymore...![]()
Once wetted there will be access for all baths during processing. Following your idea one would need a surfactant added before each step.
... surfactants are useful when the emulsion swelling has not happened or when it is still irregular. As development is complete the emulsion swelling is also complete and regular, so stop bath will work uniformly anyway on all the frame surface, so the single step where the in emulsion surfactants are useful in the developent, working only to guarentee the development induction starts synchronously in all the frame at the same time.
Thank you so much, David. That's all really interesting.Hi there,
You didn’t mention what size of film that you are using. In general, I have observed with my students that tiny white pin-pricks tend to occur more often on roll film especially when the film has been wound on and then the camera was not used for some time (possibly dust settling over time when the camera is not being used). Back in the 1960s a German photographer (sorry it was too long ago for me to remember his name) wrote a book on achieving the highest quality with Leica cameras. His advice was to only wind the film on when you are ready to take the photograph. His argument was that the film was ‘protected’ in the cassette and moving it ‘fresh’ immediately prior to taking the picture reduced the risk of dust settling on the film. Whether this is true I do not know but I have always followed this advice (not winding on film until ready to make the photograph) and have never had any significant issues with tiny white pin-pricks irrespective of the format that I was using at the time.
On the more general theme of using a pre-wash/pre-soak, if you do a search on Photrio you will find thousands of comments for and against using a pre-wash/pre-soak. In fact, some of the exchanges have got really heated in the past!
I personally have always used a pre-soak irrespective of developer or film. I have also always taught my student to use a pre-soak and I have never had any issue with it causing any problem whatsoever. I know plenty of photographers who happily do not use a pre-soak. However, whenever someone comes to me with a problem with uneven processing (mostly with 35mm films) the introduction of a pre-soak has eliminated the problem every single time.
Another reason that I use a pre-soak is that, for my photography, I have been exclusively using a two-bath developer for more than 15 years. The reason being is that the two-bath developer is reused for 15 films and the pre-soak stops the Bath A from becoming very discoloured by the dyes that are now present in all modern films.
Finally, to your original questions:
Best of luck with you experimenting,
- Tap water is fine for a pre-soak but, depending upon your local water supply, you may have to filter it to remove any impurities in the water
- You should pre-soak a film for at least two minutes
- The agitation that you use should reflect the agitation that you use for development. So, in my case, that is 4 inversions in the first 30 seconds (followed by a sharp tap to the bottom of the tank to remove any air bells) and thereafter one inversion every 30 seconds (also followed by a sharp tap to the bottom of the tank).
David.
Note: my current temporary website address is : http://dsallen.carpentier-galerie.de
Just plain no. Once the film is wet, it is wet. All chemicals will react evenly when introduced to an evenly wet emulsion.
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