Prewash colors....

[sodarum]

I have a couple of questions about color film (E6 and C41) prewash step. When I process Provia, I get a purple-blue dark color, Orange-brown for Ektachrome etc.

1. I've often wondered, what is it in raw film that causes this coloration of the prewash water, and why orange, why purple? Why the difference at all?

2. Another thing I've wondered is, how does this substance affect the first developer? Normally I don't wash the film to the point where clear water comes out (should I?), so naturally some of this purple or red substance ends up in the FD.

3. just for fun: what other colors have you noticed when developing film? I don't develop C41 at home so I have no idea what colors come out. Are they all pretty much a variation of orange and purple, or are there other colors that come out?

4. And finally: is this in any way connected with the color of the emulsion side of the raw film itself? They come in all varieties: purplish, greenish, yellowish, brownish etc. What is it that causes these differences in unprocessed film?

Thanks

 

[Photo Engineer]

There is a Looooong discussion about this here on APUG!

These are a mix of acutance (sharpness enhancing) dyes and speed trimming dyes to make the film perform the same from batch to batch. They vary in color from mfgr to mfgr due to emulsion speeds and other factors. They are harmless.

PE

 

[madgardener]

There is a Looooong discussion about this here on APUG!

These are a mix of acutance (sharpness enhancing) dyes and speed trimming dyes to make the film perform the same from batch to batch. They vary in color from mfgr to mfgr due to emulsion speeds and other factors. They are harmless.

PE

Harmless they may be, but the first time I developed C-41 myself and the pre-wash was colored, I nearly did something in my pants due to panic,