Rodinal losing power?

Juan Valdenebro

Juan Valdenebro

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I don't know if this is known...

It looks like my rodinal is losing power now that it's brown... I have not tested it, and never noticed it before with previous bottles... Or could it be because of the cold temperature we have this month even though I place the tank inside water at the same developer temperature and control it all the time? Maybe some cold gets inside anyway making the whole development colder?

If it's known that rodinal loses power, I'd understand why I feel my times are too short and give film less contrast...

Thanks!

Cheers,

Juan
 
My understanding is that this is completely normal and will not affect development. My bottles always do the same thing - the developer gets darker over time. Rodinal is known to be extremely long lasting.

I remember reading a thread on Flickr (??) some time ago where someone did tests using VERY old Rodinal (20 or 30 years, maybe??) and noticed no significant difference in film speed.
 
typhillips said:
My understanding is that this is completely normal and will not affect development. My bottles always do the same thing - the developer gets darker over time. Rodinal is known to be extremely long lasting.

I remember reading a thread on Flickr (??) some time ago where someone did tests using VERY old Rodinal (20 or 30 years, maybe??) and noticed no significant difference in film speed.
Click to expand...

Well, I've used dark rodinal half the times I've used it...

Then the only difference IS temperature...

So, a)winter is affecting my set, or b)the thermometer I bought this week (dropped and broke my 20 years old one) says 18 when it's 16...

Cheers,

Juan
 
Hmm... I wonder if it's possible the developer could have been contaminated?

I'm by no means a chemist, so I don't know how likely this is.
 
Rodinal is known to be a very long lasting developer. It is also known to have been changed many times by Agfa over its long life (120 years approx). There was an interesting article on rec.photo.darkroom (once a great resource, now messed up with all sorts of rubbish) by someone called Gudzinowicz (sp?) who discussed one of the more recent changes (still Agfa at that stage). It seems that the amount of the fairly cheap developing agent p-aminophenol could be reduced if the amount of hydroxide (even cheaper) were increased. This was IIRC evidenced by no deposit in the bottle which was in the older version somehow related to the exceptional life of the concentrate.

Agfa also removed the only expensive ingredient in Viradon Toner (selenium).

As Gudzinowicz would have said: Score Photographers 0, Beancounters 2.

I don't know about the current "Rodinal" since the demise of Agfa.
 
Thanks, John!

I'm about to think my new thermometer is just a bit different from the previous one... It's a shame I can't test the old one against it after I broke the old one... 🙂

Has anyone ever found two thermometers behaving differently? I guess 1 or 2 ºC must mean visible different contrast on film, what I'm seeing...

Cheers,

Juan
 
I have three thermometers, none of which agree!! Not sure which one is correct, but my times seemed to be good for the one I use.
 
Regarding difference in thermometers: I had a fever last week. I accidentally dropped a thermometer (one of the old mercury ones, lots of fun collecting all the little balls on aluminum foil to throw them out). I bought two new ones, also mercury, which looked identical, but disagreed by 0.8°. In a fever thermometer that's a huge difference.

2 degrees will make a fair bit of a difference development-wise. Give it an extra 15-20% of development time next time and see if you get more normal contrast.
 
typhillips said:
I have three thermometers, none of which agree!! Not sure which one is correct, but my times seemed to be good for the one I use.
Click to expand...

Oooops!

Then I guess I'll have to start developing my 18ºC rodinal at 20ºC, and my 24ºC TMaxDev. at 26ºC from now on...

This is what I saw:

For a Hexar AF focus test film (Acros) on soft light metered incident at 100, I developed as usual at 18ºC for 18 minutes. Overall contrast was too low, without dense whites on film... I mean really far from that, not close...

I thought maybe I was thinking of a wrong time or maybe my rodinal was weak (!), so I shot another urgent (now filters for Hexar AF) test roll, and developed it for 24 minutes(!)... Yet the contrast was too low... On both rolls I shot the first frames with other two cameras, and that's why I know it's not related to the Hexar AF's metering and exposure: other camera's shots are flat too, just like Hexar's frames...

To get the normal (extended) contrast for flat light I used to get with 18 minutes, now I'm needing maybe 30 minutes: an absurd time for Rodinal 1+50 if exposure is correct for box speed... So I'm thinking maybe I did develop those two rolls (the only ones done with my new thermometer) say at 16ºC although temperature reading was 18ºC... 16 is low for rodinal 1+50...

This isn't funny at all! I have no way to decide with precision my new temperatures with this thermometer, except for a hit/miss slow and boring game... 🙁

At least, once I nail a film, I'll see the thermometer's precise difference compared to the previous one, and then I'll be able to update my written data for all films/developers with confidence...

Cheers,

Juan
 
rxmd said:
Regarding difference in thermometers: I had a fever last week. I accidentally dropped a thermometer (one of the old mercury ones, lots of fun collecting all the little balls on aluminum foil to throw them out). I bought two new ones, also mercury, which looked identical, but disagreed by 0.8°. In a fever thermometer that's a huge difference.

2 degrees will make a fair bit of a difference development-wise. Give it an extra 15-20% of development time next time and see if you get more normal contrast.
Click to expand...

I agree... I guess even 1ºC, when it means using a developer in a near its low end temperature, can affect contrast clearly.

Cheers,

Juan
 
Update:

This morning I did test another film roll. My rodinal is fine. Using my new thermometer at 20ºC I get the same results in contrast I was getting with the previous one at 18ºC... I guess lately I was developing near a low temperature limit for rodinal 1+50, so a difference in temperature metering between both thermometers was too evident on film while using the new one... From now on I'll develop at my usual times all films, and just meter temperature at two more ºC... And I just bought another thermometer (the same new model) to keep it in case I drop the new one anytime... 🙂 I was a fool to think my rodinal was weak!

Cheers,

Juan
 
Juan Valdenebro said:
.....And I just bought another thermometer (the same new model) to keep it in case I drop the new one anytime... ..........
Click to expand...

And have you compared your two new thermometers with each other?

I bought three "identical" digital thermometers that weren't really cheap from a laboratory supplier. They were guaranteed to be accurate within 0.5degC. They varied in the same test liquid by much more than ±0.5degC. I assumed that the middle one was the closest, and labeled the others with the correction to match my reference. Accurate? Don't know.
 
FWIW, I've used 20 year, dark-brown Rodinal and it worked perfectly. I believe that if they still have a sample of the first Rodinal made (120 years ago) it would do a decent job.
 
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