C41 first timer!

[MattKHardy]

Hi,

As my B&W dev is working/reliable now (HP5 in ID11), I decided to take the plunge and develop some Portra 400 4x5

I will be attempting this in a Paterson Orbital developer (it’s what I am used to). I have a large plastic storage container that works as a water bath, and a Sous-vide water heater which works well. Shall be using the Digibase C41 separate bleach and fix.

For B&W I get even/reliable development with 300ml of developer and fix. Can I assume this be the same for C41?

Cheers
Matthew

[koraks]

300ml is enough for a sheet of 4x5, yes. As for evenness - you'll have to try it out.

[MattKHardy]

300ml is enough for a sheet of 4x5, yes. As for evenness - you'll have to try it out.

Thanks for your help.

I too am nervous about evenness. 3:15 is a short time. I plan on 30 second agitation rather than constant...

[agregov]

C41 chemistry is much stronger than B&W. I use 500ml to process color 4x5 in a 10 sheet Jobo drum. 300ml should be enough. And check your developer documentation because you can likely reuse the chemistry for multiple sessions (as opposed to one shot). That said, the correct dev time should be 3:15m at 38c. You can process at lower temps but then you have to extend your dev time. Given the short dev time, I would use constant agitation. Finally, make sure you pre-heat up both the developer and blix to 38c before pouring in the tank. Blix can be off +/- 5c but the developer only +/- 1c ( in an ideal world). You might want to pre-heat the tank too for about 5 minutes before pouring in the developer.

[MattKHardy]

C41 chemistry is much stronger than B&W. I use 500ml to process color 4x5 in a 10 sheet Jobo drum. 300ml should be enough. And check your developer documentation because you can likely reuse the chemistry for multiple sessions (as opposed to one shot). That said, the correct dev time should be 3:15m at 38c. You can process at lower temps but then you have to extend your dev time. Given the short dev time, I would use constant agitation. Finally, make sure you pre-heat up both the developer and blix to 38c before pouring in the tank. Blix can be off +/- 5c but the developer only +/- 1c ( in an ideal world). You might want to pre-heat the tank too for about 5 minutes before pouring in the developer.

Many thanks for your help.

Digibase instructions say that 300ml will process 4-6 rolls of film. Research suggests that 1 roll of film is roughly equivalent to 3.5 sheets of 4x5, so maybe I could keep reusing that 300ml for approx 14 sheets of 4x5?

[agregov]

The easy way to think about chemistry coverage calculation is:

1 sheet 8 x 10 =
4 sheets of 4x5
1 roll of 120
1 roll of 135 (36 exposures)

Look at the documentation that came with your C41 kit and it should tell you how many 8x10 sheets you can get with a given amount of developer. You can do the math from there. At the start, i probably wouldn’t develop more than 8 sheets of 4x5 with 300ml.

[koraks]

Many thanks for your help.

Digibase instructions say that 300ml will process 4-6 rolls of film. Research suggests that 1 roll of film is roughly equivalent to 3.5 sheets of 4x5, so maybe I could keep reusing that 300ml for approx 14 sheets of 4x5?

Activity will decrease with every roll/sheet processed. This may not be a problem with the first 2-3 rolls/sheets, but it may become noticeable after that, particularly if you want to print optical RA4. A replenishment system may be more appropriate.

[MattKHardy]

OK the results are in! My first ever C41 photo was of a Colorchecker test chart...

Vuescan raw:


Colorperfect conversion:


Post processed (de-noised, capture sharpened, contrast added, vignette reduced)


The colours seem to have come out OK.

[MattKHardy]

C41 chemistry is much stronger than B&W. I use 500ml to process color 4x5 in a 10 sheet Jobo drum. 300ml should be enough. And check your developer documentation because you can likely reuse the chemistry for multiple sessions (as opposed to one shot). That said, the correct dev time should be 3:15m at 38c. You can process at lower temps but then you have to extend your dev time. Given the short dev time, I would use constant agitation. Finally, make sure you pre-heat up both the developer and blix to 38c before pouring in the tank. Blix can be off +/- 5c but the developer only +/- 1c ( in an ideal world). You might want to pre-heat the tank too for about 5 minutes before pouring in the developer.

Hi,

I found it necessary to heat the Paterson Orbital for about 15 minutes @ 42 degree's with the lid on the bath. This turned the bath into an oven and heated the lid of the Orbital as well to 38 degree's.

I agitated constantly, but very slowly, and seem to have a lot of grain. I think next time I might try agitation every 30 seconds.

[Duolab123]

OK the results are in! My first ever C41 photo was of a Colorchecker test chart...

Vuescan raw:


Colorperfect conversion:


Post processed (de-noised, capture sharpened, contrast added, vignette reduced)


The colours seem to have come out OK.

Looks great. Be careful about over use. I'm in usa, Kodak Flexicolor LU developer replenisher in 5L batches is available separately for about 15 USD. You can use the developer one shot. Reuse your other chemicals. If you are doing small quantities not worth it. Considering the price of color sheet film it gets expensive.
Best Regards Mike