Question about agitation and Blix etc.

[SBERTIN]

Hey everybody,

I primarily use the Tetenal 1L Kit to develop medium format film. I've done so pretty successfully but I want to perfect my agitation as I've seen so many different schedules an ways.

I use the inversion method for the first 30 seconds and then for 10 seconds every minute. Is this a good method? Sometimes the Blix spills out and I guess that could be avoided by using the rotation stick but would that affect the agitation effect?

I also do not archive the film. I'm mainly shooting beauty so I scan immediately and really have no need to keep the film. In this case, do I need to stabilize or is it a waste of time?

By the later rolls, the booklet says the blix process should last for fifteen minutes which is a pretty long time. Again, if I'm not archiving so do I actually need to do this for that long? Of course if it's a necessity I will but I'd rather not if I don't have to. What difference will it make if I do every Blix process for say - only 4 minutes rather than increasing it?

 

[Bronson Dugnutt]

C-41 kit blix has less capacity than a split bleach / fix regime. The quoted blix time is probably a worst case scenario that you'll encounter as you deplete the blix. It will affect your scans.

A weak blix is the source of many defects encountered in one's DIY color dev. You can't overdo the blix step.

 

[halfaman]

Complete bleach and fix is critical for three things as far as I can remember:

1. To rehalogenate metallic silver from development. Incomplete rehalogenating leads to retained metallic silver that produces higher contrast, lower color saturation and lower sharpness.
2. To have a correct cyan density. Avoiding the cyan dye returns to the initial leuco/colourless state.
3. To remove silver halides. Incomplete removal leads to increased D-Min and subsequent lower contrast and muddy highlights.

As you can see the archival properties are not the only aspects related with the bleach and fix steps. Blix is a bit different but the three effects can be expected if not done properly.

 

[Rudeofus]

Complete bleach and fix is critical for three things as far as I can remember:

1. To rehalogenate metallic silver from development. Incomplete rehalogenating leads to retained metallic silver that produces higher contrast, lower color saturation and lower sharpness.
2. To have a correct cyan density. Avoiding the cyan dye returns to the initial leuco/colourless state.
3. To remove silver halides. Incomplete removal leads to increased D-Min and subsequent lower contrast and muddy highlights.

There are some immediately visible image effects from poor BLIX, but these will be rather weak, unless that BLIX is really toast. The issue with leuco dyes is a thing of the past, AFAIK recent film does not form leuco dyes any more.

The biggest issue with poor BLIXing and lack of final rinse is, that we don't know yet, whether these images will be of interest 20 or 30 years down the road. I threw away almost all my negatives until about 15 years ago, and I miss those older negatives now.

 

[AgX]

1. To have a correct cyan density. Avoiding the cyan dye returns to the initial leuco/colourless state.[/QUOTE

It was about the magenta dye being attacked by its own resting coupler. And about the introduction of Formaldehyde or a precursor at some stage into the process to block resting coupler. One way to introduce such Aldehyde was by a pre-bleach.
With current chromogenic films this issue seems solved.

 

[halfaman]

There are some immediately visible image effects from poor BLIX, but these will be rather weak, unless that BLIX is really toast. The issue with leuco dyes is a thing of the past, AFAIK recent film does not form leuco dyes any more.

I agree that they are not directly visible but in comparison with a proper processed negative. It happened to me the only time I used Rollei Colorchem chemistry, scans and prints were softer and saturation lower compared with what I was used to get from the same film using Tetenal or former Rollei Digibase (now Compard Digibase). When I send my film to my lab of reference negatives they are a joy to print and scan, even compared with what I do today with C-41 minilab chemistry used one-shot in a Jobo CPP2.

I have doubts about the leuco cyan thing in modern films so I put it anyway.