Adox Ortho 25 and Rodinal

Anyone used Rodinal at 1:100? At 1:50 it is uncontrollable.

Have you made any progress on that ortho 25 film? It is a type I'd like to try some day.
Michael

Guess I'll have to do some experimenting and report back.

outwest said:

Guess I'll have to do some experimenting and report back.

Click to expand...

Some large format guys discussing it here, not sure how it applies though, but can give a pointer or two
http://www.largeformatphotography.i...llei-Adox-Ortho-25-in-high-diluted-developers

I find it quite good at ISO 20 in rodinal 1:50, 7 minutes IIRC.

Minimal agitation is key with this film in my use, 15 seconds initially and then 2 inversions every minute.

outwest said:

Anyone used Rodinal at 1:100? At 1:50 it is uncontrollable.

Click to expand...

Define "uncontrollable".

It's hard to make recommendations base on an undefined problem.

Rodinal is a compensating developer. It wants very little agitation, and very gentle.

- Leigh

I use it at 1:100 and go with 60 minutes develop time.

Agitate first minute gently then set down and agitate once at 30 min for a minute then set back down till once again sometime in last five minutes a gentle agitate and inversion for another minute.

Make sure you use enough developer to cover the complete film roll or you'll be left with an ugly line of undeveloped film.

Tjack said:

I use it at 1:100 and go with 60 minutes develop time.

Click to expand...

The max recommended development time is 10 minutes at 1+50 dilution.

At any time much beyond that you've depleted most of the developer, so it accomplishes nothing.

The one effect that would be observable is that you completely lose the compensating properties of Rodinal.

So you've gained nothing and lost a lot.

- Leigh

The one hour rule is pretty standard for 1:100 ro9 stand develop time. Don't take my word for it just do a search for rodinal r09 one hour stand develop. I'm sure you could get by with less and it's probably exhausted by the end but it works good and others tend to agree.

Tjack said:

The one hour rule is pretty standard for 1:100 ro9 stand develop time.

Click to expand...

Yes, one hour is standard for stand development for any developer as far as I know.

But stand development is NOT standard for ANY developer as far as I know.

All you achieve is severe over-development and complete loss of the compensating characteristics of Rodinal.

- Leigh

When you say compensating effect of rodinal are you talking about the highlight development stoping while the shadows continue to develop with the extended time? I'll take your advice and try it out on a roll of Rollie blackbird that I'm using at the moment.

Tjack said:

When you say compensating effect of rodinal are you talking about the highlight development stoping while the shadows continue to develop with the extended time?

Click to expand...

Not exactly.

All exposed areas of the negative develop at the same rate until all exposed grains are developed.
At that point (for any miniscule area of the negative), development stops.

Shadows (thin density in the negative) develop to completion very early in the cycle.
No further increase will be noted with extended development.

Using Rodinal as designed...
Highlights will develop to the point where the developing agent is depleted, then development stops.
With heavily exposed aeas (highlights), undeveloped exposed grains still remain.
If fresh developer is available (agitation), those will continue to develop.

Three conditions will stop development at the grain level:
1) all exposed grains have been fully developed, or
2) all developing agent is exhausted at that location, or
3) development is stopped chemically (stop bath).

But film is usually developed to the point that some exposed grains in dense areas remain undeveloped.
This is controlled by adjusting the duration of the development.

The difference between thin and dense areas of the negative is called the "gamma", usually 0.5 to 0.65 or so.
The higher the gamma number, the more dense the highlights are. The thin areas don't change at all.

You'll normally find processing charts on film datasheets.
Here is one such graph for Fuji Acros developed in Fujidol (not a compensating developer):


Note how all times yield the same shadow densities (at the left end of the graph).
Max density increases with development time, and there is a difference in mid-tones.

With stand development, the entire curve moves up in the middle and to the right, but doesn't change in the shadows.

- Leigh

Additional thought...

Are you using the proper amount of developer?

You need 10ml of Rodinal for each "roll" of film. This is true regardless of the dilution.
A roll is anything you can proof on one 8x10 sheet of paper, i.e. one 36exp 35mm roll, one 120 roll, four 4x5 sheets, etc.

- Leigh

outwest said:

Anyone used Rodinal at 1:100? At 1:50 it is uncontrollable.

Click to expand...

Personally I think that 1;50 Rodinal dilution is one of the worlds greatest developing dilutions.............My favourite for the brown gold anyway.