D-23

[Mark MacKenzie]

I haven't had any luck searching the forum for D23 or D-23. I did read Ken Lee's website regarding the developer.

Am I right thinking that D-23 compensates more than HC-110? Say I develop for Zone VIII to be the same density with HC-110.
What difference would I see? Less separations in mid zones?

Thanks for any thoughts.

[Kevin J. Kolosky]

pretty hard for someone else to tell you what you would see. Best to see it for yourself. Get a little bit of metol and sodium sulfite and try it to see what it does for you. that is what I am doing.

[Ken Lee]

D-23 is simple. HC-110 has fantastic keeping properties. If you develop the same film to the same contrast index, it would be hard to tell the difference, except perhaps by grain.

[Mark MacKenzie]

Now thats the kind of experienced information I can use! Thank you, Ken.

[Ken Lee]

"What difference would I see? Less separations in mid zones?"

Separation in the midtones is a matter of contrast index: how steep is the straight-line portion of the curve. That is controlled by degree of development (time/temperature/dilution/agitation).

Grain/sharpness/acutance aside, separation at the extremes of the tonal scale - the toe and the shoulder - are where certain film/developer combinations shine over others. This translates to greater effective film speed at the low end, and better separation and at the high end.

You might enjoy reading this article (http://unblinkingeye.com/Articles/PCat/pcat.html) on Pyrocat HD: it shows how different films respond to the same developer. Some are very linear in their response to changes in development time, while others are not. You'll also see how films are remarkably linear except for the toe and shoulder. Some have no shoulder at all - which is wonderful.

[Mark MacKenzie]

Thanks, Ken. Great article on Pyrocat. Pyrocat seems very popular and I have wondered if I am missing the boat by not trying it but the staining scares me. I haven't ventured yet into alternative printing yet. But mainly, I don't think I have learned how versatile HC-110 is. I get good results with my portraits but my landscape negatives have been way too contrasty so I need to learn to pull as well as push film. Thats why I was looking at D-23. Maybe its magic bullet thinking. I liked your write up on it as well as the simplicity of the chemical makeup.

I may have thrown another variable in the mix by buying a box of TriX 320 which I have never shot before. I have been shooting Acros and FP4+. So I'll test it in HC-110 and get a feel for it before I change developers. I don't know why but it seems that HC-110 is not as popular, maybe not as exotic.

Its that magical mid range I think that I want to learn how to manipulate.

No shoulder means that highs don't block up quickly? Empty highlights bother me. I can tolerate some empty shadows, though. The TriX 320 curve looks to have no shoulder at all. Then same with Acros. Now FP4 shows a big shoulder.

What I want is to be able to shoot a subject like your Tulips and have all that wonderful midrange tones and also to go out and shoot full sun and deep shadow subjects with the same control and expression in the mid tones. I think I will stick to HC-110 unless advised otherwise and learn to pull and push and stand develop. By the way, the BTZS sounds like the approach to take but it makes my head hurt.

Thanks for the help... hope you don't mind the meandering.

[Ken Lee]

If you think the above-cited article conveys that FP-4 has a large shoulder, you may be confusing the 2 different kinds of graphs. The graphs on Page 3 (http://unblinkingeye.com/Articles/PCat/PCat3/pcat3.html) show how density increases with exposure - and those show no appreciable shoulder for FP4, especially in Pyrocat HD. Those are the graphs we usually refer to when discussing toes and shoulders :cool:

The graphs on Page 4 (http://unblinkingeye.com/Articles/PCat/PCat4/pcat4.html) are something different - they show how contrast index increases with increased developing time. Most notable are the Bergger and Photo Warehouse films, which respond poorly to changes in development time. They reach a certain contrast index, and basically stop. That's a bad thing for those of us who want to be able to control tonality and contrast. On the same page - at the other end of the spectrum - we find TMY and HP5+, whose response to changes in development are practically linear, which is very desirable.

If you don't like staining developers, then don't bother. As you probably know, Ansel used Tri-X and HC-110 for years and did just fine with it. Some still use that same combination. I like Pyrocat HDC because when mixed in Glycol, it has a long shelf-life equivalent to HC-110, is simple to mix from materials, and has the advantage of proportional grain-masking and suitability for UV processes.

The magic bullet - if there is one at all - happens when a beautiful subject and beautiful lighting come together.


Thanks, Ken. Great article on Pyrocat. Pyrocat seems very popular and I have wondered if I am missing the boat by not trying it but the staining scares me. I haven't ventured yet into alternative printing yet. But mainly, I don't think I have learned how versatile HC-110 is. I get good results with my portraits but my landscape negatives have been way too contrasty so I need to learn to pull as well as push film. Thats why I was looking at D-23. Maybe its magic bullet thinking. I liked your write up on it as well as the simplicity of the chemical makeup.

I may have thrown another variable in the mix by buying a box of TriX 320 which I have never shot before. I have been shooting Acros and FP4+. So I'll test it in HC-110 and get a feel for it before I change developers. I don't know why but it seems that HC-110 is not as popular, maybe not as exotic.

Its that magical mid range I think that I want to learn how to manipulate.

No shoulder means that highs don't block up quickly? Empty highlights bother me. I can tolerate some empty shadows, though. The TriX 320 curve looks to have no shoulder at all. Then same with Acros. Now FP4 shows a big shoulder.

What I want is to be able to shoot a subject like your Tulips and have all that wonderful midrange tones and also to go out and shoot full sun and deep shadow subjects with the same control and expression in the mid tones. I think I will stick to HC-110 unless advised otherwise and learn to pull and push and stand develop. By the way, the BTZS sounds like the approach to take but it makes my head hurt.

Thanks for the help... hope you don't mind the meandering.

[Mark MacKenzie]

Well this is very interesting, Ken. What I was comparing was the manufacturers' data sheets with charts titled Characteristic curves. Ilford with Ilfotec HC (big shoulder), Acros with Fujidol, D-76, and MicroFine (no shoulder), then Tri-X 320 in D-76, and HC-110, (also no shoulder).

The FP4+ density seems to shoulder and stop below 2.0 while the two others extend straight. I just noticed that the X axis for Ilford is called Relative Log Exposure measured from 1 to 4, and the two others are Log Exposure (Lux Seconds) measured from -3 to 1.0 . Maybe this is the explanation.

If PyroCat strightens out this shoulder, I can understand it being desirable.

Anyway I have just begun trying to understand the curves and contrast index curves so I might be totally mis-interpretting.

Your example of the Bergger and the Photo Warehouse CI graphs helped me understand those charts, thanks.

I need to crack open that box of Tri-X and start playing around. Thanks!

[Lynn Jones]

The last film with a straight line was Super XX and that has been gone for decades. All the rest either go belly up or belly down. The best way to test is expose at focus infinity, minus 3 stops (Z2), normal (Z5), plus 3 stops (Z8), processes read densities, draw a straight line from Z2 to Z8 to yield a GBar (average gradient) for normal contrast at .50 and adjust exposure for Z5 at .70. That by definition is world standard normal, however, you may wish to alter that for yourself. You will be surprised to find that many companies alter their standards for their own purposes. One major company uses .55 for their GBar while another important company uses .60 still others to .65 (it makes their film speed appear higher). This assumption is based on condenser or condenser emulating enlargers. Most of the film manufacturers use lensless systems which will cause your testing to be different from theirs.

Lynn

[Mark MacKenzie]

Hi Lynn, thanks for your post.
New to these charts so I'm trying to understand. I'll include the Kodak Tri-X charts. 7803378034

I will test as you suggest from Z2, Z5, and Z8. (I wonder if I can find or make a target that has just those zones without the expense of a step wedge.)
The GBar (average gradient) at .50 means to find the development time that produces that contrast index? Or I am confusing apples and oranges.

I'm disappointed to think the film manufacturers would not standardize but not surprised.

When you say belly up or down, you mean in the HD curve that the "straight line portion" is not straight at all but convex or concave?

I was confused by the shoulder on the FP4 curve while the Kodak curve stops while still straight. (Like the Acros graph.) Seems like it would shoulder some time, though. I mean, density can only get so dense then no more.

Thanks

Mark

[Ken Lee]

http://www.kenleegallery.com/images/forum/HP5D23Curves.png

I may have misunderstood a lot. Here's a set of BTZS curves for Ilford HP5+ developed in D-23 1:1 at 70 degrees. They come from a BTZS film test done for me by Fred Newman of the View Camera store, and they are consistent with my own test results. He exposed the step-wedges, I developed the film, and he scanned and analyzed the data.

From left to right, we see contrast curves for 5 development times: 16 min, 11 min, 8 min, 5.5 min, and 4 min. (This chart shows more information too, like the Effective Film Speed at different development times. For example ISO 250 when developed for 8 minutes. It's a predictably ho-hum result, showing that HP5 and D-23 1:1 is a fairly mild combination - which I like because when developing by inspection, longer developing time affords greater control when handling many sheets at once.)

The only curve that shows a trend towards shouldering, is the 4 minute developing time, which represents an N-3.5 development. It's so short, I'm surprised we see much of anything.

[Mark MacKenzie]

Hey Ken,

Its my confusion. Anyway, here is the Ilford curve from the data sheet showing the curve.

78039

I think all charts would show this leveling out if they extended so far just at what density I'm not sure.

Mark