With some films, among those EFKE, the manufacturer recommends the prewet to
remove the anti-halation coating before development. I use EFKE KB100 and
always prewet. You can also see the colouring effect if you prewet T-Max (or
was it Ilford Delta 3200?), the water comes out all purple. It also colours the
developer so it must have a lot of dye in it.
There is a discussion of prewetting here:
http://www.apug.org/forums/archive/index.php/t-5267.html
Jonas
Earl Dunbar wrote:
> Date: Mon, 11 Apr 2005 21:21:46 -0400
> From: Earl Dunbar <edunbar@xxxxxxxxxxxxxxxx>
> Subject: [OM] Re: Efke/Adox was Safekeeping T20 TTL connectors
>
>
> Uh, the prewet, IIRC, is just to make delivery of the developer
> "smoother". The idea is (was?) that if the film has had a bit of a
> soak, the residual water on the film after dumping the soak will deliver
> the developer more evenly. I'm not sure if this was ever tested in any
> way that was really meaningful, but I used to use the soak for sheet
> film pretty consistently. But I abandonded it for roll film since I
> neveer noticed any problem with streaking or uneven development by
> omitting it with roll film.
>
> Earl
>
> Walt Wayman wrote:
>
>>Now about the prewet, which is a really silly term because you can't really
>>pre-do anything, so I'll just call it the first water bath. (I mean, I see
>>directions that call for preheating the oven. Excuse me, but isn't that
>>really just heating the ****ing oven?) Anyway, I'm obviously pussyfooting
>>around and avoiding the question of why to do it. I know I once knew, but
>>now I've forgotten. All I can say is that's what the J&C directions say to
>>do.
>>
>>I wish I could authoritatively tell you that it dissolves and removes the
>>antidefractional postextemporal and defuzzificational coatings so the
>>developer can reach the previously hermetically sealed and renegade-proton
>>shielded emulsion and go to work immediately, but that would not be really
>>truthful. Or maybe it would be and I just can't remember. I do know,
>>however, that it does something, because the water comes out looking like
>>Kool-Aid. I'm still not sure what flavor it is, though the grandkids don't
>>seem to like it much. :-)
>>
>>Walt
>>
>>
>>
>
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