Question on prewash of color neg and slide film

[Steven Ruttenberg]

I prewash my black and white film till water is pretty much clear and it works great and seems to help extend usefulness of developer.

I am getting ready to develop color neg and slide film. I am guessing I can also prewash as well till water is essentially clear. For black and white my precast is at development temp of 68 degrees For. I would assume that I should prewash slide and color neg at the appropriate development temps as well correct?

I would also assume I can use photoflo for the color neg, what about slide film? I really don't want to use the squeegee thing unless it will not hurt neg or slide. The photoflo works great on my black and white negatives.

Okay, let me have it :)

[interneg]

Pre-washing current films is really not worth it (unless you are shuffle developing multiple sheets of BW film in a tray) - not least because it is potentially going to dilute the developer & get the film to the wrong temperature or unevenly wetted (bad idea with colour - leads to crossovers, streaks etc) & while it might help aid even development if done competently, unless you are having problems stemming from not pre-wetting, I'd avoid it. A water bath, on the other hand, is a very good idea for getting the tank, chemicals etc up to process temperature.

After processing & washing & before hanging to dry, use the process correct stabiliser on colour films - they are designed to preserve the dye image, & not doing so may cause the images to degrade faster. Do not rinse the film after stabilisation, squeegee it & hang it to dry. Do not use Photo-Flo & the best squeegee you own is your fore-finger & middle finger. Make sure you thoroughly wash all processing equipment that comes in contact with the stabiliser.

[koraks]

I prewash my c41 at the same temperature as the developer to bring the film up to (or close to) the required temperture. It works fine for me.

[Steven Ruttenberg]

So far, my pre-washing works great, just curious if there is something different about color neg and slide film that would not sit well with a pre-wash. Photoflo is the bigger question. It works great on bw film to keep from getting streaks etc as film dries, but will it affect the color film or slide film if it is the last step.

I have heard not to use fingers as squeegee, but then everyone has their own method that works for them.

I like the squeegee idea as it is fast and keeps fingers with oils from touching film which I try to avoid at all costs.

[koraks]

I use photoflo or an equivalent (dishwasher shine in my case) with all my film and have had no problems with it ehatsoever. With 35mm, I dry the shiny side of the film with a piece of kitchen towel immediately after hanging the film to dry. Absolutely zero drying marks etc whatsoever.

[Steven Ruttenberg]

I use photoflo or an equivalent (dishwasher shine in my case) with all my film and have had no problems with it ehatsoever. With 35mm, I dry the shiny side of the film with a piece of kitchen towel immediately after hanging the film to dry. Absolutely zero drying marks etc whatsoever.

Interesting. That is good to know. No signs of degradation on slide film or color neg I assume.

[interneg]

So far, my pre-washing works great, just curious if there is something different about color neg and slide film that would not sit well with a pre-wash. Photoflo is the bigger question. It works great on bw film to keep from getting streaks etc as film dries, but will it affect the color film or slide film if it is the last step.

I have heard not to use fingers as squeegee, but then everyone has their own method that works for them.

I like the squeegee idea as it is fast and keeps fingers with oils from touching film which I try to avoid at all costs.

Scratches from poorly looked after squeegees are far worse than the far remoter chance of finger oils being transmitted to surfactant covered film.

Bad pre-washing might remove critical components within the emulsion layers that are there to enable correct processing & it should be noted that nowhere in Kodak's C-41 documentation do they suggest a pre-wash with current colour materials. Unless you are absolutely able to prove that it has no deleterious effects, don't pre-wet.

Finally, & not to lecture you or Koraks (but this is important), please do not use or recommend the use of surfactants other than those supplied for the purposes of being used as wetting agents on photographic materials. Unless you know the totality of the ingredients in a commercial dish soap (and unless you're an analytical chemist, I doubt you will) you will not know if the other ingredients, perfumes etc will have bad effects in 5, 10, 25 years. Yes, the right materials cost more, but the difference is massively important to the potential longevity of your work & if you don't feel your art is worth the cost of a bottle of Photo-Flo or Ilfotol...

[Steven Ruttenberg]

Scratches from poorly looked after squeegees are far worse than the far remoter chance of finger oils being transmitted to surfactant covered film.

Bad pre-washing might remove critical components within the emulsion layers that are there to enable correct processing & it should be noted that nowhere in Kodak's C-41 documentation do they suggest a pre-wash with current colour materials. Unless you are absolutely able to prove that it has no deleterious effects, don't pre-wet.

Finally, & not to lecture you or Koraks (but this is important), please do not use or recommend the use of surfactants other than those supplied for the purposes of being used as wetting agents on photographic materials. Unless you know the totality of the ingredients in a commercial dish soap (and unless you're an analytical chemist, I doubt you will) you will not know if the other ingredients, perfumes etc will have bad effects in 5, 10, 25 years. Yes, the right materials cost more, but the difference is massively important to the potential longevity of your work & if you don't feel your art is worth the cost of a bottle of Photo-Flo or Ilfotol...

I don't use anything not supplied for the developing, etc. I am an engineer, not a chemist. I will review the Kodak information you mention. So far, most of what I have seen is people doing at least one pre-wash/wetting prior to developing. This pre-wash is at the same temperature required for developing, etc.

Well, if I squeegee, I would definitely take care of it and only use it after inspecting it. You can wash your hands prior to using your fingers which would help out considerably.

[interneg]

I don't use anything not supplied for the developing, etc. I am an engineer, not a chemist. I will review the Kodak information you mention. So far, most of what I have seen is people doing at least one pre-wash/wetting prior to developing. This pre-wash is at the same temperature required for developing, etc.

Well, if I squeegee, I would definitely take care of it and only use it after inspecting it. You can wash your hands prior to using your fingers which would help out considerably.

Should re-iterate that Kodak recommend a pre-wash explicitly only for shuffle developing multiple sheets of BW film in a tray - and Ilford are pretty wary in general about pre-washes. Most of the time otherwise it's people repeating what their 'guru' told them & not what the manufacturer recommends.

[chassis]

I prewash C-41 film.

Steven, there is another film-oriented site where your questions are covered extensively. There is a gentleman with userid “Photo Engineer” who formerly worked for Kodak and has made substantial contributions to the discussions on that site. Google will find it and I suggest you review some of the information there.

[LabRat]

The main reason for a presoak for B/W is to even out the emulsion so it absorbs the dev evenly with the thicker emulsion used with B/W, but color films are much thinner, and developed in warmer solutions (which will expand them to the max quickly), so it would not be needed...

Some MP films have a rem-jet backing that must be removed before processing, but our sheet films are OK..

That should save you a step...



Steve K

[Steven Ruttenberg]

I prewash C-41 film.

Steven, there is another film-oriented site where your questions are covered extensively. There is a gentleman with userid “Photo Engineer” who formerly worked for Kodak and has made substantial contributions to the discussions on that site. Google will find it and I suggest you review some of the information there.

I found that site earlier today, Phototrio and was reading about C-41 and E-6. Thanks for the info!

[Steven Ruttenberg]

The main reason for a presoak for B/W is to even out the emulsion so it absorbs the dev evenly with the thicker emulsion used with B/W, but color films are much thinner, and developed in warmer solutions (which will expand them to the max quickly), so it would not be needed...

Some MP films have a rem-jet backing that must be removed before processing, but our sheet films are OK..

That should save you a step...



Steve K

That would save some time. I may experiment with some sample images and see if it helps or hurts.

[Oren Grad]

Steven, there is another film-oriented site where your questions are covered extensively...

I see Steven already found it. But for the record, there's nothing wrong with naming Photrio here.

I do second your recommendation to look for postings by Ron Mowrey (Photo Engineer) if you want to understand good practice with color negative film.

[Steven Ruttenberg]

I see Steven already found it. But for the record, there's nothing wrong with naming Photrio here.

I do second your recommendation to look for postings by Ron Mowrey (Photo Engineer) if you want to understand good practice with color negative film.

I am. I am gonna give this a go this weekend.