Diluting Rodinal

[dadsm3]

I've noticed that some members like to dilute their Rodinal 1:25, 1:50, and some 1:100. I was just wondering what the benefit or effect is of a very thin dilution and extended developing time?
Thanks,
Mike

 

[Socke]

Me, too!

Especialy 1:100 is interesting, I have a roll HP5+ here and can't find times for Rodinal at 1:100. My tank takes 450ml so the 4.5ml Rodinal may be just sufficient, but how long to develop?

 

[tetrisattack]

The higher the dilution, the more the compensating effect. Strong solutions of rodinal give a more aggressive density curve than lower dilutions. Important to note is that, while there is no practical solvent effect with rodinal (which is to say, you can't control grain via dilution as you can with D-76 or other solvent developers), grain seems (to me) larger at strong dilutions. Presumably this is chemically-induced grain clumping.

Another notable phenomenon is the edge effect. High dilutions lead to long times and people tend to agitate infrequently, which in turn encourages the development of edge effects. This may be more or less attractive depending on the physical size of your film -- what looks nice on 4x5 as a subtle boost in acutance might wind up looking like a hideous halo around your subject on 35mm.

I'm not totally sure about that grain clumping thing. I'm planning to do a study on that as soon as I regain access to a high-powered microscope, which should be next fall at school. 🙂

 

[Peter S]

I love Tri-x shot at 200 and developed in Rodinal 1+50. It just gives me smoother, creamier negatives (bigger tonal range) and finer grain in comparison to stronger dilutions (I mean with more developer); it also makes negatives easier to scan because you do have reduced contrast developing like this. Temperature and agitation also play an important role of course.

Agfa says you should use 10ml of Rodinal per film, but that is nonsense. I get away with 6 and I have read about other using less.

You also might want to visit www.apug.org an important place of worship in the Rodinal cult.

Have fun experimenting

Peter

 

[Xmas]

Mike

Agfa recommended 15 or 20 minutes at 1:100, but quote low EI

For a copy of their chart try google - agfa + rodinal + times

Noel

 

[ZorkiKat]

Dilution, as the others have said, gives more compensating effects. Contrast is tamed down- for instance, well-exposed strong highlights don't develop (in the negative) bulletproof so detail still comes through in the print or the scan. Speaking of scans, lower/longer contrast negatives tend to scan better too.

As for grain size, "ORWO Formulae" (the official ORWO formulary/developing instruction book) said that R09 (aka Original Rodinal) more dilution will give finer grain. Perhaps this is more of appearance than true size reduction, for
a negative with longer tonal scale will likely make the transition between grains less obvious than one with a shorter tonal scale.

The grain seen in the print is not really the film grain- rather it is the spaces between the negative's actual grains.

Jay

 

[Mackinaw]

Especialy 1:100 is interesting, I have a roll HP5+ here and can't find times for Rodinal at 1:100. My tank takes 450ml so the 4.5ml Rodinal may be just sufficient, but how long to develop?

Take a look at the massive developing chart for times for this film/developer combo:

http://www.digitaltruth.com/devchart.html

I've standardized at Rodinal 1:100 when I use Efke 25. I can't give you any technical details as to what happens at this dilution, but I just like the effects. Nice tones and little apparent grain.

Jim Bielecki

 

[titrisol]

Have you read the "Appreciating Rodinal" article in unblinking eye? I recommend it greatly.

Rodinal at 1+100 or 1+200 can be used for stand or semistand development, and the bromine drag is really minimal, while the mackey lines (edge effects) are noticeable
I like it a lot with EFKE 25 since it helps controlling the contrast.
I also use it for FP4 and EFKE 100 when exposed under high contrast situations

When using such high dilutions time is less important, 20 minutes or 22 make almost no difference, and I prefer going for 30 agitting once every 5 minutes.

 

[Trius]

Agree with Titrisol about stand/semi stand development. Agitation is often not appreciated for its effect on grain.

Mike, 15 minutes would be too short for HP5 at 1:100. I'd go 20 or so.

 

[dadsm3]

Thanks again to the helpful people who make this forum the best.
Mike

 

[titrisol]

YIKES!!!
I didn't realize you were planning to use it on HP5 20 seems wwaaayy too short.
To ballpark the times, add 40% each time you increase the solvent
i.e. 1:0 -> 1+1 or 1+1 -> 1+2
But when going to such high dilutions 1+50 -> 1+100 duplicate the time and agitate less.
With HP5 I'd be tempted to go for 40-45 minutes agitating once every 7 or 8 minutes

Agree with Titrisol about stand/semi stand development. Agitation is often not appreciated for its effect on grain.

Mike, 15 minutes would be too short for HP5 at 1:100. I'd go 20 or so.

 

[Xmas]

Mike

I did not mean to confuse, in their chart Agfa quote for 1:100

mins EI
15 100
20 160

If you are going longer then presumably you are pushing it...

I'd a pasted the chart id I was computer literate.

Noel

 

[dadsm3]

It wasn't me who was doing the HP5+, it was Socke.....mine was just a general question, but actually I'm doing Tmax400 shot at 400.

 

[Xmas]

Mike

Yes I normally have to tear off the end of the box.

Noel

 

[derevaun]

I've settled on 1:100 for 40 minutes, agitating every ten minutes with four or so inversions. I go with the assumption that the shadows are going to develop to their potential, and that contrast (highlight density) increases proportionally to overall agitation. If I want strong contrast, I do more initial agitation.

I've gotten consistent results with 3ml of Rodinal for a 36 exposure roll of 135. I usually use more total volume just to have the tank about 2/3 full.

 

[StuartR]

Fuji Acros at ISO 100 in Rodinal 1:100 for 18 minutes, agitation for 15 seconds of each of the first 3 minutes, and then 1 inversion every 3 minutes. 68 degrees.

Above is the recipe for heaven.

 

[John Robertson]

A handy way to measure accurately, get a 10ml syringe, (without the needle!!)
when I explained, my doctor was more than happy to give me a few!! The type I got has markings at 1ml intervals.

 

[titrisol]

That is a very logical assumption, the initial agitation is just to "wet" the film IMHO
When I use 1+100 for 35mm film I prefer 4+400 ml to get a little bit of safety net 🙂

As for measuring small quantitities, drugstores will give the syringes away for dosage of medicine for kids (at least in the US) and those are 5ml marked in .5 ml, at least in Eckerds.

STUARTR: Great recipe for Acros, pictures look awesome.

I've settled on 1:100 for 40 minutes, agitating every ten minutes with four or so inversions. I go with the assumption that the shadows are going to develop to their potential, and that contrast (highlight density) increases proportionally to overall agitation. If I want strong contrast, I do more initial agitation.

I've gotten consistent results with 3ml of Rodinal for a 36 exposure roll of 135. I usually use more total volume just to have the tank about 2/3 full.

 

[Schlapp]

Stand development with high dilution 1:100-1:200 etc are great to control contrast.