How important is to pre wash film before develop it?
Is the pre wash just to make the film at the same temperature of the developer before developing? Or is it also important to take out the film chemistry residues before developing?
I developed a couple of time without soaking the in to water and I didn't notice any difference.
It's not recommended by Ilford, it's not necessary.
Some like to pre-wash, others don't, it can help with rotary processing.
For every photographer you ask, you will get a different answer about pre-washing.
I use a pre-wash for two reasons:
I use a (re-usable) two-bath developer and I do not like Bath A becoming full of the dye.
A long time ago I had some problems with uneven development (streaking on 35mm film) and pre-soaking solved this.
Whenever, a friend who does not pre-soak comes to me with streaking or other development problem, I always recommend pre-washing and this always solves the problem.
I don't do a prewash, but I did try it in the past.
For the people who routinely use a prewash, do you find that since the film has absorbed water from that step, instead of developer, does the development slow and do you compensate with more time, higher temp, or more concentrated developer? Would that bit of water from carry over in the film, and probably a little bit in the tank/reels affect your development in other words?
I use a pre-wash to solve streaking issues as above, and also to equilibrate developer and film temperature. I've never modified my dev time/conc and I haven't noticed any ill effects...
Originally Posted by David Allen
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As Ian said above, some do a pre-wash, some don't. It washes off the anti-halation dye and I find that it promotes more even development, especially with sheet film. I do it, but if I happen to forget it, I don't worry about it too much. And no, you don't have to compensate for anything in development. If there's any real difference in the film either way, it isn't enough to be concerned about.
In more years than I care to remember, and over what must be thousands of films over the years, I have never pre washed my films, I have never seen the need,it is not nessary,
If using 2 bath or divided developer, a pre-soak is not recommended (see Anchell). I rotary process all sheet film , and find a pre-soak helpful for one shot developers.
van Huyck Photo
"Progress is only a direction, and it's often the wrong direction"
I prewash lith film as I was regularly getting streaks and uneven development. But I develop this by safelight in trays. And I recently introduced a prewash to my C-41 processing. But regular black and white film -- no.
While neither Kodak or Ilford say a pre-wash is necessary with their normal films/developers and normal tank procedures, there are some exceptions and cases where it can help:
Originally Posted by marciofs
1. If it takes long to fill the tank (large tank, or small tank with slow-filling lid). Photo Engineer makes the point that unless the film is uniformly/quickly immersed in the developer, you can potentially get uneven development from splashes etc as you fill the tank if the film is dry. Problems with uneven development tend to occur at the beginning of development.
2. When minimal-agitation or stand/semi-stand procedures are used, a pre-soak is generally recommended
3. When developing times are very short, a pre-soak is generally recommended to help ensure uniformity
4. When developing sheet film (multiple sheets) in a tray by hand shuffling, a pre-soak is necessary to prevent dry sheets from sticking together
5. When using a film or developer or process for which a pre-soak is specifically recommended by the manufacturer
6. In general, if uneven development is a persistent problem, try adding a pre-soak to the process, which may or may not help