Caffenol C-M and C-H (RS/RSA)

Reinhold of Caffenol.Blogspot.com fame has been so kind as to post an article I wrote on how the RS and RSA versions of his recipes came about, and why I named them as I did.

Hello coffee (ab)users, 

I'm very happy to present Eiriks report about his reduced soda/ascorbic-acid versions. Have a nice reading, and I recommend visiting his sites linked below. He's a great photographer and a very nice guy. Thank you so much, Eirik.

Happy developings - Reinhold

That's what Eirik wrote:

I promised Reinhold a long time ago I would write an article on the (RS) and (RSA) versions of his recipes.

Like many others, when I started out with Caffenol I perused the net for tips on where to start. I concluded pretty early on that these 8tsp of this, a pinch of that, and a cup of other recipes, were not going to cut it for me. Reinhold’s precise and predictable recipes however were exactly what I was looking for. In addition to reading everything on his blog, I joined a Caffenol group on Flickr, and a long ongoing thread on the Scandinavian APUG forum to discuss and share experiences.

I like to be accurate in my work, but I am also lazy. So I soon tried out premixing Caffenol, instead of having to dissolve powders and mix them up for every development. My approach was to dissolve the ingredients in larger quantities and store them in light and airtight bottles. Then mix them, one third each, when developing. For this to work, each solution had to be 3 times the prescribed strength. And it worked well. The ingredients did not go off as quickly as some had thought. The coffee started to develop mold at 8-12 weeks, and the ascorbic acid oxidized gradually to be useless after 15-20 weeks. The soda kept forever, but was susceptible to crystalising in my storage space in the basement in cold weather. Evidently this was due to the combination of higher concentration and low temperature. In warm weather the soda was stabile...................

Continued here: Caffenol C-M and C-H (RS/RSA)

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. ;)