2) What is the effect of dilution of Rodinal? How does 1-25,50,75,100 changes sharpness, >contrast
and such?

The higher dilute you use it, the higher the sharpness and the lower the contrast will be.

3) How long does Rodinal keep in concentrate after the bottle has been opened?

Forever. Not virtually, but actually. The bottle will be rotten away before the content goes bad.

In the old times Agfa used glas bottles - I have a scan of an article going back to 1961. An
englishman (or was is a scot? ,-) found a bottle in his attic and sent it to Agfa - it was from
1911. They ran a few strips and compared it with fresh Rodinal and could find no practical

Today they are using HDPE instead of glass - it allows more air to pass than glass. But Agfa fills
them under a protective atmosphere, the fluid doesn´t oxidize that much as long as the bottle hasn
´t been opened.

If you compare fresh R09/F09 with Rodinal you´ll notice the color difference - the first two look
like year old Rodinal even when coming fresh from the factory.

Color won´t influence activity. But be careful when emptying the bottle, there are crystals on the
bottom of the bottle which are insoluble and which might scratch your emulsion if you allow them in
your tank.

4) Should I have metered at a different speed? All speeds I found on any dev charts >where either
400 or 200 asa.

Most producers ratings are overly optimistic (for marketing reasons) - 400 ASA films usually end up
at 320ASA and any film will loose speed with Rodinal.

The only films coming close to the producers rating I have used are the Fotokemika emulsions (Efke)
- they are faster than the printing on the boxes.

5) About the fixing temp. The fixer wasn’t new, but I tested it with the Hypo Check.

Use a two step fixage, thus you´ll be safe anytime _and_ economic.
Temperature should be close to developing temperature.

It really surprised me because I lifted the film out at five minutes and was still quite >purple.
At ten it didn’t look any less purple, but I continued at 12 minutes anyway.

Way too long. Fix strong and short. Make a clearing test (put a piece of undeveloped film in the
fix and watch it clear out. Make that time doubled (conventional emulsions) or tripled (t-grain/
delta grain) your actual fixing time.

What’s up with that?

The purple stain are leftover sensibilisation dies, making the emulsion respond panchromatic. You
can wash them out with a soda bath (20g of sodium carbonate per liter), with a two step fixing and
with sunlight - 2h on the window will bleach it out.

I know now my favorite film and developer!