Pushing Superia 800 to 12800

[Athiril]

Alright I finally got around to bothering to try it. Was suspicious about preflashing outside of anything apart from compressing a range to be more easily printed in the dark room.

Preflashing + extreme pushing of C-41.

Test roll is Superia 800.

Developing method was C-41 + 600mg/L of Potassium Thiocyanate (thought this may give me extra speed) for a time of 6 minutes, followed up by a sodium carbonate bath to continue shadow development (although skip this, all it does is increase base fog, I forgot about that in C-41). The KSCN isn't a necessity.

Pre-flashing method. I rated the film at 12,800. I put a tissue over the front of the lens and metered on a neutrally coloured wall. Converted the reading to 12,800 since my camera (AE-1) only goes up to 3200. That'll meter for 18% grey, or 'Zone V' for 12,800.

I started 4 stops below that, but it turns out, pictorially, the best one I had one was with a pre-flash of 'Zone III' (or 2 stops underexposed from a middle grey reading rated at 12,800), I didn't go any higher than that on the pictorial scenes.

So basically it was an even white OOF exposure, then double exposure of the scene I want to shoot.

It worked better than expected, so now I want to see if I can get results at 6400 with preflash like I can without it at 1600.

All from the same roll

3200 no preflash

12800 no preflash

12800 + 12800 Z1 preflash

12800 + 12800 Z2 preflash

And here it is, like magic
12800 + 12800 Z3 preflash

 

[Photo_Smith]

I recognise some of the equipment there, the neg sleevers and slide mounters-I've probably mounted 100,000 slides on that very make of machine.
Is that a Fuji Fp500 series film developer at the end?

In a bizarre way I kind of wish I'd never got out of the Lab business...

 

[Athiril]

5700 iirc, FP-232b behind that, and SHP-5080 in front of it, and other stuff not pictured.

 

[BLKRCAT]

this is very interesting. So without the sodium carbonate bath results would be even better?

 

[Athiril]

The detail would be about the same I reckon.

I think you can safely just pre-flash + heavy push to expand the contrast, and should be most of it.

Though I want to try it with a split-bath too, which I got good results on previously before.

 

[sweat100]

Thanks for the information with detailed study. I intend to push Superia 1600 to 6400 because of film shot in low lighting. From your study, if I just do a +2 stop during colour developing stage, I would get poor results?

I am not so sure what is the pre flashing and how is it done? At which stage was the sodium carbonate added?