Every photographer you ask about pre-soaking film will give you a conflicting answer. In my personal experience, whenever someone approaches me with uneven development/streaking/overdevelopment near to the sprocket holes on 35mm film/etc I always recommend pre-soaking the film and this always solves the problem (and one should bear in mind that the short development times of HC110 in a rotary processor is a particular area to watch out for). On the other hand, there will be many here that will state that in xx years they have never ever had a problem when not using a pre-soak.
As Gerald wrote:
Whether you pre-soak or not what is important is consistency.
consistency and repeatability is the key to good film processing plus this will help you to identify any problems and/or changes that you may wish to make to achieve the results that you prefer.
So the fairest answer would be that you need to choose one method or the other and stick with it until you personally hit a problem. I would suggest using a pre-soak as it will eliminate any potential problems but that is just my opinion.
Before deciding, just let me address a few comments on here:
I have never pre-soaked a film and would imagine that pre-soaking the emulsion with water prior to developer may cause uneven ingress of developer which needs to replace the water.
I have never ever observed this possible 'problem'. Quite the opposite, introducing a pre-soak has always solved processing problems.
And that is the exact reason as to why Ilford does not recommend it.
Unless something has drastically changed, I have never seen Ilford either recommend using a pre-soak or suggesting that it should not be used. The last time I looked their PDF on processing film did not mention it. However, it did suggest using a squeegee (which I personally think is bad advice because I have seen so many people who do this and who have ended up scratching their films.) and that you can use a hair drier to dry your films (also something that I think is bad advice as I have seen so many people struggling with dirty film - i.e. stuck on dust)
Don't pre-soak if you are using a reclaimable developer, as you cannot be sure of the resulting dilution due to tank carry over.
I read this all the time but, just think, how much is actually being carried over 1ml?, 2ml?. I have exclusively used a reusable two-bath developer for the past 15 years. I have never experienced any problems with dilution of the first bath BUT, by using a pre-soak, it does keep the first bath looking much clearer as the anti-halation dye is removed during the pre-soak
Anyway, your call but decide based on the facts - and the way to do this is process two test rolls with/without pre-soak and see which you prefer.
Bests,
David.
www.dsallen.de