N+1 and N+2 Tri-X 400 in Rodinal (No Time To Test)

Fragomeni · Nov 15, 2013

Hi all,

Just a quick question here that I'm hoping some of you can help me with and I'm sure that something like this has been asked before but I can't find exactly what I'm looking for right now. I'm in a time crunch with a few experiments and I like to know what you're using for N+1 and N+2 development for Tri-x 400 in Rodinal. Let me clarify quickly, I'm well aware of how to test and that development times are variable from person to person and equipment to equipment. That's not my concern so lets please not drift off into an overly repeated thread about the importance of testing. With that said, I'd love to know what times and dilutions you're using for N+1 and N+2.

A little info about my film that'll maybe help find a solid match that I can run with for the sake of time: Tri-X 400, 120, exposed at 400. I'm interested in Rodinal dilutions of 1:25, 1:35, 1:50. Let me know your thoughts! Thanks!

Bill Burk · Nov 16, 2013

Hi Francesco,

If you were to choose D-76 1:1 for a developer, I'd be qualified to give you relevant times.

If there were a time/CI chart available, I'd be able to help you interpret it. The available charts all indicate that you can expect average contrast 0.65 from the given times.

This is already approximately N+1.

Assume this makes a good print of a subject with one stop less range than an average scene (6 2/3 stops) on paper Grade 2.

A scene with two less stops of range than average, which you would want to develop N+2, could be printed on a higher contrast paper. If the development was to average contrast 0.65, it would print well on paper Grade 3.

So if my calculations and interpretations are correct... You can't go wrong by using the published times!

joh · Nov 16, 2013

Hi,
my times for TriX in Rodinal 1+50 (Adox Adonal)
N 8:55 TriX@200
N+1 12:45 TriX@250
N+2 18:00 TriX@400

For the N development the densitys are I=0.10 log.D and VIII=1.02 log.D
The negatives are for printing with the condenser head from my Durst 138.
I'm prewetting 4 minutes, and the movement is 1. minute steady and then 3 inversions at the beginning of every following minute.
The temperatur is 20°C.
I should be able to calculate the data for your enlarger/paper, if you say which density you need.
hope it helps.....

Harold33 · Nov 16, 2013

joh said:
Hi,
my times for TriX in Rodinal 1+50 (Adox Adonal) [...]

Is this for 4x5 or for something else ?

By the way, your curve is really S-Shaped. Not so common by these days.

joh · Nov 16, 2013

The test is made with 35mm film and I use the data with 135 and 120.
This is not a film curve, on the left is your gamma and beyond is the development time, the "s" is realy strange
but that is the data I get out of the test

Ian Grant · Nov 16, 2013

With Rodinal it's far better to use more concentrated developer of N+1 & N+2 so you're on the right track.

I preferred 3 in 100 for N and 1 in 25 for N+1 & N+2, 1 in 50 for N-1 and N-2, I only used Tmax 100 and AP/APX100 & AP/APX25 in Rodinal so can't suggest times for Tri-X, I wouldn't process a fast film in Rodinal and always used Xtol (replenished) for Tmax 400.

Ian

Bill Burk · Nov 16, 2013

joh,

That's very helpful, you've added something that isn't available anywhere else on the Internet!

Harold33,

The curve is NOT a characteristic curve, it is a curve showing the contrast achieved at different development times. It's normal for that curve to be wavy.

joh · Nov 16, 2013

Ian,
you are right, Rodinal is not a realy good developer for higher speed films but Tri X in Rodinal is not so bad at all, there is a lot of grain (especially in 35mm),
but for me, it's a beautiful grain.
I tested the TriX recently in Rodinal and Atomal 49. In Atomal it was the first time in 25 years that I get the box speed for a N development, but I prefer by far the look of the combination Tri X and Rodinal. With my 4x5" films I use Rodinal also in 3 different dilutions, but the Tri X react's so good to the times that I tested in this dilution that I skipped further test's.....

Bill, you gave me the idea to put the chart online

Bill Burk · Nov 16, 2013

Francesco,

This is the chart I use to choose the Contrast Index that I intend to develop my film... It's based on an 0.4 flare factor.

So you can use this chart to figure what joh offers, "to calculate the data for your enlarger/paper, if you say which density you need"

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A little narrative how I use the chart... I take for granted that 7 (or 7 1/3) stops is about = N (it's a leap of faith but that's the leap I make). Then N+1 is one stop less Scene Brightness Range (three columns to the left), etc.

On the Paper Grade - LER scale, I picked 1.0 because it's the average of two negatives of mine that I consider extremes of what I would like to print (I stopped working on paper analysis when I found a density I know meets my needs). You may choose to target any Paper Grade or density.

Likewise, when you don't like the result the chart gives for Contrast Index or Development Time, you can explore "what if" scenarios to find Paper Grade you might have to use if you compromise Development Time. In this sense, I like to look at the chart to find a time that keeps my resulting negative under Grade 4.

Bill Burk · Nov 16, 2013

By the way, while it is normal for contrast to jump faster earlier in processing, I imagine the true characteristics of the film/developer combination is smoother, gradual slowdown of contrast growth. I don't think there is a second acceleration of the curve.

I maintain my Time/CI curves with scatter points of actual runs and although my first chart shows a curve with a similar S shape, I find enough variation in my processing... to suggest my original curve isn't extremely accurate. Still, it provides a means to determine a plan... and having a plan backed by experiments makes me comfortable with my process time decisions.

joh · Nov 17, 2013

Bill,
I never get such a strange curve before. The curve only shows the development times from 8 to 22 minutes.
I normaly test the times 4:00 , 5:30 , 8:00 , 11:00 , 16:00 , 22:00 and 30:00 minutes.
In this case I didn't test the 30:00 minutes, what annoys me today. If there is an error, it is at 22:00 minutes point and it would easily shows up as an error, if there was a further point....
On the other hand, TriX don't react like any other film I tested in Rodinal. With all other films I always need different dilutions to get a full range from N-X to N+X.
For the Adox CHS 100 II (a realy nice film) in 4x5 I use dilutions from 1+50, 1+100, 1+200 and for HP5 in 4x5 I must use 1+25, 1+50, 1+100 to get the full range.

Bill Burk · Nov 17, 2013

joh,

I wouldn't be concerned about the curve. At 22 minutes, you may be nearing "gamma infinity" where the contrast is no longer increasing. I think if you did a spot-check of any one time from 8 to 20 minutes, you will get an additional data point to help you see what is going on. It could be some simple reason. Maybe at 22 minutes your developer warmed up.

RalphLambrecht · Nov 30, 2013

why do people never have the time to do it right but always find the time t do it twice I'll never understand.

Fragomeni · Nov 30, 2013

Wow. Just seeing this now. Lots of traveling and no Internet (replying via phone signal from the side of a cliff in VT, fun!). Anyway, thanks everyone for your thoughts! Much appreciated.

Also, Ralph, regimented testing isn't always necessary or ideal depending on the approach and what you're trying to do. Looks like you don't remember but take a look in your email inbox from a few years ago in which you helped me at length with the testing I was doing for my experiments with inkjet paper negatives. I'm no stranger to testing and i certainly value it when i need it. I just don't need it for this.

Again thanks everyone. Headed back up the cliff now

Bill Burk · Nov 30, 2013

Bill Burk said:
By the way, while it is normal for contrast to jump faster earlier in processing, I imagine the true characteristics of the film/developer combination is smoother, gradual slowdown of contrast growth. I don't think there is a second acceleration of the curve.

I keep rethinking what I've said here... I was talking off the top of my head, giving bad information and could be wrong... I was reading Photo-Lab index and the book mentions that some development byproducts DO cause acceleration of development. So a wavy line COULD reflect a process reality.

erikg · Nov 30, 2013

If you have Selenium toner you could tone the negatives to get you to the N+2, and avoid the added graininess from the extended development. That's usually my option with 35mm.

joh · Dec 8, 2013

Ralph,
I tested this Film/Developer combination primarily for getting the N and N+1 developing times for use with my (condensor)enlarger and paper.
The times I have here at home are from n-3 up to n+3. In the real world I developed this combination up to n+2 and that worked well and as expected.
The strange part of this curve is in the range of N+3 (for the gamma I need) and if I had tried the 30 minutes developing, I might have reached N+4.....
If this was single sheet film for my 4x5 I had been realy interested in the N+3 times and if I could reach N+4 I might have tried it someday. But this test was for 135 and 120 film and I use it, if I want to walk around without much equipment and weight. For the way I work, 35mm film is much too long for real Zonesystem use and before I carry 5 or more 35mm bodys, I realy prefer my little 4x5 technika.

N+1 and N+2 Tri-X 400 in Rodinal (No Time To Test)

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