Semi Stand Rodinal Disaster

[mikepry]

Getting a Grip on Rodinal

Well I just couldn't dial in the semi stand development for the life of me. I was getting very eratic results making it impossible to formulate a logical timeand dilution. Very strange as I am very methodical in the darkroom. So, I started using the 1:50 and have gotten much better results. I have settled in at least for now with 8 min agitating GENTLY for the first 30 seconds and then 10sec every minute after that. I am rating it (Fomapan 200) at 160 but I maybe will drop my developing time some more as the negs are still pretty contrasty and the highlight densities are on the edge. I don't want to bring my film speed up anymore as I'll lose my shadows. I can print through using MG paper and split filter printing which is what I do anyways but still I may go down to 7-1/2 min and see what happens. I know that doesn't line up with the norm as far as dev. times go but am using a very old camera (Leica lllc) and since there is no meter in the camera, my Minolta incident meter. What's interesting to note is that the late 1940'sSummitar is not a contrasty lens so I think 8min is a tad strong. Everyones system is different in terms of calibration and what not so the shorter dev. time doesn't really concern me. I just wanted to report in and thank everyone for taking time out of their day to respond to this post.

Here is an image of the back of my house I have done with the 8min time. It is a scan from a print. It was a very bright and crystal clear autum day and I wanted to see how far I could go with the tonal range. I am happy with this combo and look forward to having some fun with it. Thanks again.

Leica lllc/5cm Summitar
Fomapan 200 @ 160
Rodinal 1:50 @ 8min
Ilford RC MG Brilliant

Peace,
Mike

 

[Thomas Bertilsson]

Looks good, Mike. I'm glad things worked out for you.
- Thomas

 

[gainer]

Since the subject was mentioned in passing, I'll ask it here. What is a good definition of "gentle agitation" and what is its virtue?

 

[mikepry]

Since the subject was mentioned in passing, I'll ask it here. What is a good definition of "gentle agitation" and what is its virtue?

Well, It's kinda like trying to tell someone how to wiggle their ears. Gentle is not rough or not robust. I don't know any other way to explain it. Maybe 4 or 5 inversions in a 10 second period is what I ended up doing. As far as it's virtue, and I should say it's virtue for me in my darkroom ............ when I didn't agitate gently my results were substandard. When I started easing up on the method of agitation I started to get much, much better results. I hope that helps explain where I'm coming from.

Mike

 

[gainer]

I wonder if others have different interpretations. The problem that agitation is supposed to solve is uneven distribution of active ingredients, and it must do so in our case before the distribution becomes uneven enough to cause uneven development. If unevenness is desired for some esthetic purpose, it usually is not random unevenness but somehow proportional to density of the developed image. That is something we cannot control in the way a painter controls the image, so we hope the developing solution does it. Periodic agitation, it seems to me, should be vigorous enough to restore the distribution of active ingredients to initial conditions before the random changes induced during agitation can produce unwanted random changes in the image.

The products of development cause local changes in the development rate that may wander from place to place due to local changes of specific gravity. Every chemical reaction is likely to cause local changes in temperature as well as chemical composition that result in changes of specific gravity. These changes have rates that are generally reduced as the concentration of active ingredients is reduced, so we have learned that we can extend the time between agitation periods by using less concentrated developers.

 

[mikepry]

Well, I get about half of what you say due to my 9th grade education but there is one (glaring) factor you have omitted entirely and that is "Darkroom Demons." That's right, I got em. They rear their ugly little heads every so often and then go away for awhile. They came out during my semi stand development tests big time. Things happened that made no sense whatsoever. So, I surrendered and tried something else. I guess I'll try the semi stand thing w/Rodinal at a later date. Basically I got tired of sucking fumes and wanted to get out in the fresh autum air and make some photographs.