Film Developing - Pre-soak?

I am often asked if I pre-soak my film before the developer step. Here are my thoughts:

The idea is that putting your loaded reel of film in a water soak before the developing stage improves the quality of developing, by eliminating a couple of possible problems.  The pre-soak is mainly used when developing film with a less than 5 minute developer time.  Less than 5 minutes in the developer step, the film can experience a uniformity issue because the liquid has to be absorbed by the emulsion.  This takes a bit of time, depending upon the temperature.  By soaking in water first, this softens the emulsion and prepares it for the developer.  A water soak will also remove the anti-halation layer from the base of the film.  This layer is added to prevent light from reflecting off the pressure plate and back through the film twice creating a glowing effect on the highlights.   Polypan F film has no anti-halation layer and it will give you this effect intentionally. If you pre-soak your film, this layer will come off and you will see the water is stained when dumped out. I have seen greens, magentas and purples.  This is normal. 

Since most B&W film, processed at 68 degrees will not yield developer times less than 5 minutes, I do not include a water step. Color negative film on the other hand I do.  It certainly will not hurt the film to do it.   Here is the breakdown:


B&W Film (traditional, non-C-41) if the developer time is 5+ minutes:
No.  

If less than 5 minutes, I use a different dilution or lower temperature to increase the time.

C-41 Color Negative Film or C-41 B&W Chromogenic Film:

Yes!  Color Negative Film is processed at about 100 degrees +/-.  The developer step is 3:15.  as in 3 minutes, 15 seconds. That is awfully short.  I include a one minute water soak first, with water at 100 degrees to prepare the emulsion for the developer.