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Shen45
6-May-2010, 19:46
I know this is dangerous but I was thinking the other day. I use BTZS and would like to use Rodinal BUT Rodinal is an energetic developer that runs out of steam reasonably quickly.

For example to get a good 4 minute development time with a useable SBR of say 9 dilution has to be adjusted to lets say 1:60 but by the time the developer runs its course at 16 minutes it may only produce a an SBR of 6 Whereas D76 1:1 can produce an SBR of 9 to 4 [4 minutes to 16 minutes]

Question can Metol be added to Rodinal in some way either in the diluted mix or to the concentrate?

And if so how much?

Ian ???? :)


regards


Steve

IanG
7-May-2010, 02:46
Steve, Metol is the wrong developing agent to add, you'd need to add Hydroquinone or Pyrocatechin to the Rodinal, but some other chemicals would be needed as well.

Agfa did publish a formula for a P-Aminophenol/Hydroquinone developer sometime in the early 1900's.

However as a once long time Rodinal user for all my films 35mm to LF, Tmax and Agfa APX I now prefer to use Pyrocat HD which has all the benefits of Rodinal and greater flexibility.

Ian

Robert Hughes
7-May-2010, 13:57
Sounds like adding grape juice to a tequila sunrise. Yeah, you could do that, but ... :confused:

CG
7-May-2010, 14:50
One developer with para-aminophenol and hyroquinone is Kodak DK-93, a general purpose film and paper developer.

Information reproduced from: www.jtsatterlee.com/PhotoNotes.html

Kodak DK-93

Water 125F . . . . . . . . . . . . . . . . 500 ml
Para-aminophenol Hydrochloride . . ..5 g
Sodium Sulfite anhyd . . . . . . . . . . 30 g
Hydroquinone . . . . . . . . . . . . . . . 2.5 g
Sodium Metaborate . . . . . . . . . . . 20 g
Potassium Bromide . . . . . . . . . . . . 0.5 g
Water to . . . . . . . . . . . . . . . . . . .1 L

Use undiluted

Starting point development time:
Tray 8 mins.
Tanks 9 min

Develop rolls film in trays about 7-1/2 minues or in tanks about 9 minutes at 68F(20C).

Develop professional and sheet film in tanks about 6 minutes and in trays about 5 minutes at 68F/20C.

For colder tones, double the amount of Sodium Metaborate and develop for 2 minutes at 68F(20C)

For warm tones on paper use without dilution and develop for 2 minutes at 68F(20C)

In either case, the tones given with developer are slightly warmer than the normal tones of D-52 and D-72.

Recommended also as a substitute for metol-hydroquinone developers for those subject to skin irritation due to metol.

Shen45
7-May-2010, 21:06
Thanks guys, even you Robert :), the formula is interesting CG. Ian as always you knowledge is invaluable. I have plenty of Hydrpquinone so I may try some just to see the result.

Steve

IanG
8-May-2010, 01:08
The Agfa formula is in this PDF, but I've yet to convert it to Metric, The units are US not UK Imperial.

Agfa Rodinal developers (http://lostlabours.co.uk/Uploads/1910_Rodinal.pdf)

Ian

philbed
8-May-2010, 09:01
Dear Steve,
I also use BTZS and I experiment strange things with Rodinal. The first time I have run the tests, I prepared as usual a 1:50 dilution for the 5 tubes i.e. 6 ml of Rodinal for 300ml of developer. As you I cannot build a good density for a 16mn development time. As Rodinal is cheap, I run a second test but I mix a liter of developer (20 ml of Rodinal). The results was better and a 16 minutes times gives me a SBR of 4,33.
I am not a scientist nor a chemist but I suspect than too little Rodinal in the solution exhaust the solution too quickly. I run the test with Acros and I was not convinced by the combination Acros/Rodinal. I prefer D76 which give me a better local contrast.
Kind Regards,
Philippe from Burgundy, France

Jim Noel
8-May-2010, 11:15
Phillipe has hit upon the answer. The total quantity of diluted developer is not what is important in attaining density, the quantity of developing agent has that job.

a liter of developer at 1:100 contains 10 ml of developer. If only 800ml of that solution is is used there will only be 8 ml of developer thus resulting in underdevelopment if the quantity of film requires the full 10 ml.

J. Patric Dahlen
14-May-2010, 23:57
I saw in an old photo yearbook (Das Deutsche Lichtbild from the early 30's) that one photographer had used two developers for his film. Half the time with a MQ developer and the rest with Rodinal. There was no discussion about it, only the information on the equipment and chemicals he used for the published photo.

J. Patric Dahlen
15-May-2010, 00:14
From the PDF of the 1910 book Ian posted:


"Agfa"-Rodinal has excellent keeping qualities. This applies not only to full bottles but also to those that have been opened and partly used. Although it has been observed that in opened bottles "Agfa"-Rodinal becomes darker in color, still this change produces no noticeable effects upon the working properties of the solution.

Still true one hundred years later. :cool: