Caffenol -- an experiment, and why I'll look elsewhere

[grommi]

Dad,

your samples are making the problem clear. That's really annoying. I made a close inspection of my older Caffenol-C-M developed films including Acros 100 as 120 film. Indeed I can see a tiny portion of overdeveloped borders, but only if I brighten up the shadows extremely. With a proper black adjustment, it's not visible any more. But it is there.

When adding 2 g/l KBr as a restrainer, the effect is completely gone, even with very low agitation. See the sample picture from my last blog posting:

http://caffenol.blogspot.com/2010/08/perfect-development-with-caffenol-c-l.html
from my last blog posting.

You can't see anything on the unexposed film leader, the reel coverd borders or the frame gaps.

Cheers - Reinhold

 

[Denverdad]

Reinhold,

Thanks for checking. Since I first started playing around with caffenol recipes it has always been curious to me that some people get this as an obvious effect while others don't seem to observe it at all. But the fact that you can see it in some of your earlier efforts when you specifically look for it - even if it was fairly subtle - has me wondering if there isn't something intrinsic to caffenol that gives it a propensity for these effects. Two possible routes for investigation would be to look at the type/brand of coffee , and whether distilled or tap water is used (maybe higher mineral content in tap water somehow suppresses the effect?). Its all just speculation on my part and I probably won't be looking actively to find the answer as I am starting to get what I think is a very workable recipe and technique now.

In any event, it is good to know that potassium bromide has the multiple benefits you report - working to eliminate the edge overdevelopment and also reducing/eliminating fog. Personally, I have mixed feelings about using it though. One of the main things which attracted me to caffenol in the first place was the idea of being able to make a developer completely out of common (more or less) household substances. To me that is the "cool factor" about caffenol which really makes it stand out from other developers. I still get the biggest kick out of telling people I can develop film in coffee! But for me, KBr is just a little out of bounds relative to that concept. Don't get me wrong, that's just my particular slant on things - I have nothing at all against anyone going that route. In fact I really enjoy hearing about all the variants people out there are trying! But for now I think I will try to build my recipe just from the kitchen and laundry room cabinets. (and yes, I am completely sweeping under the rug the fact that the fixer doesn't fit into this silly purist scenario of mine either. Oh well, sue me!)

As for fog, I think I mentioned somewhere before that I have found common table salt to be an effective fog reducer in caffenol-C. Now there's an ubiquitous kitchen item for you! About 10ml/liter seems to be a good starting point if anyone wants to try it out.

 

[grommi]

Hi Daddy,

you probably can't imagine how much I agree deep in my heart. Didn't almost all of us start with that Caffenol-thing because it's so much fun to make a film developer from household ingredients? And yes, I'm also vain enough to have my fun telling people who may not know anything about film development, that the images I show them are made with the help of ordinary coffee! Maybe the primeval Caffenol is the biggest fun. Take coffee and throw in anything that makes it a bit alkaline - done! You may even take a drain cleaner instead of soda.

But also many of us are looking for improvement. The better is the enemy of the good. A breakhrough was the addition of Vitamin-C. Tweaking with salt or seawater, or - as in my case - bromide. I agree that with bromide an invisble border is crossed. But with the good conscience that the soup is still environment friendly and can be poured down the drain without thinking. A bit of acidic stop bath afterwards, and fish is happy to. The fixer remains a problem, until today nobody found a solution and probably won't in the future.

I must urgently try your salt suggestion, but to be honest, the benefit from the bromide is so big that I will probably stick with it. You can buy it here in pharmacies. Aren't pills household ingredients? :-DDD Yesterday I received a message from a guy in Iceland, who had no probs to get it there in a pharmacy. KBr is also used in homeopathy, that can't be evil ;-)

Coffee imho has the intrinsic property to produce fog and uneven development like probably any other developing agent. I guess that all commercial developers are using some kind of restraining technique. Maybe the effect is specifically high with coffee. I don't think it depends on the brand. But who knows?

So lots of things to think about and it's good to talk with you and the other guys here - thank you all very much.

Warm regards - Reinhold

 

[Denverdad]

Reinhold,

No problem. "It's all good!" as they say.

Also I checked into the availability of potassium bromide. I am still not sure whether I can purchase it locally, but I checked at Freestylephoto.biz and the stuff is actually pretty darned inexpensive. They sell a pound of it for about $11 (USD). At that rate (assuming your recipe and my tank size) it works out to less than $.03 per roll. Pretty good bang for the buck I would say!

 

[grommi]

Hi Dd,

thank you for the info. For about the same price you can get it here from chemistry distributors, I bought it in the pharmacy only because I could hold it in my hands after a few of hours. Cheers - Reinhold