Kodak Tri-X (TX400 or 400TX) in Caffenol-C-H

I´ve recently developed two rolls of Tri-X. Both over expiry, one of the previous emulsion, and one of the current. Both worked out well.

Tri-X has always been Tri-X. But look at the designation on the box, and on the film rabate you´ll see that indeed they are different. Modern (post 2007) Tri-X is called 400TX. The former emulsion is called TX400 or just TX. Reputedly the newer emulsion is more fine grained and requires shorter development. Finer grain? Possibly, not that I would fret over big fat grain on the older version, if I was so lucky to find a cache. It´s still very good in Caffenol. I did however develop the two films (very) slightly differently.

Modern Tri-X, exposed at EI400, in Caffenol-C-H(RS) and 0.7g/l of Potassium Bromide (KBr). A small recap of the RS recipe bottom of post.

14 minutes and 30 seconds @ 20C/68F. 12 initial inversions, and 3 every top of the minute as usual, save the last at 14 minutes (i.e. stand from 13 minutes). Water stop, 1 minute. Normal fixing and washing. All at as close to 20C/68F as possible.

Modern Tri-X, box speed, Caffenol-C-H(RS), 14m30s @ 20C. DIY 6x17 Camera

Modern Tri-X, box speed, Caffenol-C-H(RS), 14m30s @ 20C. DIY 6x17 Camera

Click on the pictures, they are large and you will see just how good Tri-X can be. I really got lucky on these. Shot with my DIY 6x17

A prior attempt to expose a roll of Trix met with just about every problem in the book. Firstly the back on the Super 66 has developed a light leak. Luckily the frame shown below, and the first frame are exempt from damage, all the others are not.Secondly the first 5 frames of the film, all have a dark lower 1/4. Why is a mystery. Again this frame went clear.

Thirdly the self timer switch on the leaf shuttered lens got engaged without me noticing. Once I thought I had the shot in the bag (the mirror swinging up makes a loud kaaawhuump) and I started to walk away I heard the dreadful sound of the timer clockwork. I rushed back and reframed blind (the mirror was still up of course, obscuring the view, so why am I looking into the viewfinder?). And better framing than this is difficult even with finder. Missed the focus by a foot though. So now my reflection is more in focus than I had hoped. Ah well, that´s Sod´s law I suppose.

But back to business. This is the older emulsion, and yes there is slightly more grain, but still very good for a 400 speed film. Tonality is good. Due to the problems with exposing this film, the example frame is not the best.

Again, Caffenol-C-H(RS), this time with 1.2g/l KBr. All else equal.

Old Tri-X, box speed, Caffenol-C-H(RS), 14m30s @ 20C. Kowa Super 66 w/150mm f3.5

Caffenol-C-H vs C-H(RS)

In a 1 liter solution, each:

Sodium Carbonate, anhydrous 54g - 40g

Ascorbic acid 16g - 16g

Instant coffee 40g - 40g

Potassium Bromide (KBr) whatever, same for both. Between 0.6 and 1.5g/l depending on emulsion.

As you can see, only the amount of soda (sodium carbonate) is reduced. This lowers the pH, makes the developer less active. My experience says it´s still active enough. I haven´t really adapted my times much.

Benefits over regular C-H (same applies for C-M(RS) over C-M). I find grain is slightly less pronounced, and the tonal gradation is smoother, slightly less contrast maybe. 

With regards to the two Tri-X versions. Both are perfectly good films. I´ve already ordered a couple of bricks of modern Tri-X. ;)