using a Jobo 3010, I took advantage of sheet film and ran through an experiment, to evaluate TMax 100, Delta 100, Plus-X, and FP-4. realizing the suggested Xtol processing times were different, I selected a good compromised developing duration, and exposed all films on the same scene. I was quite surprised, and it is consistent, that TMax 100 yields the lowest speed of these films. appears to be about a stop difference between TMax 100 and Delta 100, which should be close. having said that, the processing times actually tend to overdevelop TMax, so this is a mystery. Plus-X, FP-4, and Delta 100 densities match well, whereas TMax 100 stands alone.

I was very pleased with TMX in 35mm, such that I am surprised by these findings. Delta 100 is beautiful, but not quite as sharp as TMX.

does this bear out the conventional wisdom?

-- Daniel Taylor (aviator@agalis.net), December 29, 1999

Answers

How does TMX have the lowest speed yet get overdeveloped? Do you mean that the recommended dev. times Kodak gives for TMX are too long in XTOL?

I shoot sheet TMX at 100 right now and don't have shadow detail problems; what was your measured speed?

-- John O'Connell (joconnell@adelphia.net), December 29, 1999.

the developing times for Delta 100, per spec, are a minute longer than for TMax 100. and so, I was surprised to have overdeveloped TMax and underdevelop Delta 100, and find much greater densities with the Ilford film. nothing scientific at this stage. I picked up John Sexton's book and noticed he rates TMax 100 at ISO64, which is more in-line with what I have observed.

-- Daniel Taylor (aviator@agalis.net), December 29, 1999.

Expose for the shadows and develop for the highlights. Without the proper exposure your developing scheme is useless and has no bearing on any of these films or the developer. John shoots Tmax 100 at iso 64 because that is what his equipment needs to get consistent results in the shadows and knowing how John prints it is what gives him the shadow densities he is looking for. I expose Tmax 100 at anywhere from 120 to 50 depending on what I want the film to do for me. Your developing times have little meaning without the rest of the calibrations necassary to get a print to have the desired look anyway. And matching fp4 and plus x against the T and Delta films is useless also. James

-- Mr.Lumberjack (james_mickelson@hotmail.com), December 30, 1999.

useless to you, of value to me. TMax 100 emulsion is clearly slower than the rest. nothing scientific, just a very general test to jump start a more qualitative assessment.

-- Daniel Taylor (aviator@agalis.net), December 30, 1999.

I'll repeat. Slower to you with your equipment and working conditions. I tend not to make blanket statements about film and processing based on any of my half-assed tests because others, especially newcomers to this sport, are easily convinced about x,y, or z and get caught up in believing in such nonsense and waste valuable time that could be better spent learning to do things like calibrate their equipment and materials. Throwing completely different films together into a certain developer and developing them all for the same time, when clearly they all have different requirements, isn't much of a test. I just hope that those photographers out there who haven't used Tmax, don't get the wrong assumptions about the film based on your shoddy test. Or Plus x for that matter. Tmax is a wonderful film. I used to hate it because of conclusions I made based on the wrong assumptions. Until I calibrated my proceedures properly, there was no way I could get the film to behave like other more proficient photographers. But when I finally ran the proper tests, I was able to get an incredible amout of variability out of the film. So all of you new people out there. Let that be a lesson to you. Don't look and listen to what others say and do. Test for your self. Don't be slaves. Be leaders. James

-- Mr.Lumberjack (james_mickelson@hotmail.com), January 01, 2000.

exactly. so do some crazy things. mix it up. experiment. I should not have used the word densities within the description of my ad-hoc experiment. however, great things can come from serendipity and taking chances, so I will continue to do so, and encourage others to do so as well. I am well versed on TMax 100, and individual evaluations over the last few weeks consistently showed TMax 100 to be a slower emulsion. and so, my experiment followed to get a general idea. as I previously stated, it is valid if only to launch further investigations.

which is exactly what I plan to do today.

-- Daniel Taylor (aviator@agalis.net), January 01, 2000.

James and Daniel,

Must we bicker and argue. From the way I read it, Daniel was just giving us information he found in his experiment (and ALL experiments are valuable). I did not see him trying to convince me one way or the other. Yes you are right James, his experiment was flawed in many aspects and I would never use his finding to govern my photography. On the otherhand, don't you ever just wanna know what will happen if you do x to y? That's half the fun of darkroom work. Everything doesn't always have to be scientifically sound, as James warns, as long as you don't take your data and live by it. Good luck to both of you in your photographic ventures.

-- Josh Randall (joshrandal@excite.com), January 06, 2000.