what happens to the colors of E6 and C41 when you push?

When my C41 chemistry started to get a little weak my film was coming out really blue (in the positive) so I had to push from 3.5min to 5min to get normal looking results. Whether your pictures will still be less blue if you push your film under normal conditions, I cannot say, but that was my experience.

 

C41 is normally easy and more forgiving. I've underdeveloped my stuff and still came out acceptible.

On proper E6 with 6 baths you develop b&w picture separately with the First Developer - this you can push or pull as you like or as film specs recommends. Later separately with Color Developer you develop colors to it - this must be stpot on, off the mark or messed chemical will start to create casts. Ie Fuji Provia 400X can be pulled to ASA200 or pushed all the way to ASA1600 and some say even ASA3200 can be acceptible, with just normal slightly increased grain during the FD-process, with nice "spot-on" colors from CD-process. So pushing is allright in proper E6 within film's tolerances.

 

There is always the risk of 'crossed curves' when you push c41 development. Crossed Curves are caused by the 3 colour chanels developing at different rates so that when the development is perfect the three colour characteristic curves meet at one point and give you an easily printable negative. If they don't when you try to print a 'pushed' negative there will always be a colour cast that you will find almost impossible to get rid of.
Modern films are far more forgiving than those of say 20 years ago (still C41) but you will nevertheless get a less than perfect negative.

 

Please note that the FD step in E6 processing has to develop all three color layers in lock step or you get color crossover in the end result. The fact that dyes are only formed in the second step is irrelevant. Since pushing and pulling are not exactly new techniques, most modern films and dev kits do quite well in this regard. I had great results from pushing Provia 400X up to 1600, and decent results with New Portra 400 pushed to 3200.

 

+1.
Fuji Provia 400X is
- excellent @ ISO 200/250 pull
- outstanding @ ISO 400
- excellent @ ISO 800 push 1
- very good @ ISO 1600 push 2

It is one of the best all-round color films ever made. A real "hidden film jewel" of the market.
I've used this film for portraits, fashion, landscape, wildlife (animals), air-shows, architecture, family shots, nightlife, as travel film on vacancies. And I've got always excellent results.
I am extremely satisfied with this film, therefore it is one of my main used films, both in 135 and 120.
Highly recommended!

Best regards,
Henning

 

I have older documentation from an 80's era Kodak colour data guide that for two stop (or was in more than two stop....) you needed to dilute the colour developer.
I have never been pressed to try this.