I made an inadvertent test on the latent image characteristics of both films. I shot two sheets of each then misplaced the holders for about 3 years. I processed the film according to the original exposure/development plan. I found that there was no noticeable increase in base fog on the TMax 100 film. There was an overall base fog of about .3 on the Delta 100. However, both negatives printed well with both negatives having the planned print density range. The inference being the base fog on the Delta 100 was like a neutral density filter had been pasted to the negative. Both films did not show loss of speed or contrast due to the prolonged storage under less than ideal conditions. This speaks well of both films.
I occasionally use cyanotype to illustrate exposure to my high school photo students and the UV absorbing characteristics of TMax eliminate using those negatives from this activity.
Interesting information. It is possible that TMX emulsion is more stable, but also it could depend a bit of when each expired, and preserving conditions before the shot.
I guess that TMX may have other sensitizing dyes, perhaps discovered for color film. That (sometines nasty to remove) pink tint suggest a different dye sensitizing apporach, I guess more advanced.
Anyway I also think both films are equally good for most situations.
Do you think Spectral Sensitivity is different ?
Do you think that TMX UV blocking feature will modify a bit the look for shots done with sunlight illuminated subjects ?
Should place a UV filter on D100 to have same look ?
In the immortal words of the late Fred Picker: TRY IT.[B][/B
Of course !!! With film nothing subtitutes testing, you are right...
Anyway informaton from others also help to interpret what you test.
Thanks for make me dicover Picker: http://www.fototv.com/refining_the_print
I have always treated TMax100 as such. I prefer a light sky, and a yellow on TMax100 always darkened the sky more than I wanted. This past couple of weeks I was out in Death Valley. I had both TMax400 and FP4+ loaded in the 8x10 holders (and some Tri-X 320). I only had a yellow filter for the 300mm, so used the FP4+ with that lens (and filter); and TMax400 with the 250mm and the 360mm if the sky was significant to the image. I figure the skies will be rendered fairly close between the two films.
I re-took this image (6yrs ago...palms are now dead). Same film (FP4+) as the original, I took the original with and without a yellow filter. I printed the one with the filter, I believe. I re-took it with a slightly longer lens (360 vs 300mm) from about the same spot, no filter. it will be fun to see how they compare.
"Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China
The Kodak spectral plot is for uniform energy (although, technically, it should not say erg/cm2, but erg/cm2/nm). While the Ilford plot is whetever density is produced by a 2850K blackbody. The latter has vanishing energy in the blue. Had the Ilford plot been normalized for energy, it would (in relative terms) have more blue and less red sensitivity than the Kodak one. Can't be more specific without having the respective data in numeric form.
Side note #1. Interesting to me! this is the first time I realize that Kodak and Ilford plots are normalized in different ways. The rising sensitivity towards the blue/violet end of the spectrum of TMX (and presumably Delta 100 when plotted in energy units) is good reason to use a yellow filter (which I did! on empirical grounds)
Side note #2. Is there an official definition of orthopanchromatic? Ot has this been made up for hype, like "high silver content"? I don't even know if it means "in-between panchro and ortho" or "panchro, only more so" (even more red sensitive)?
Thanks for your information.
Not al all, you can directly relate Pinaverdol sensitizing dye to orthopanchromatic performance.
Well, there is a big difference between Ortho and Panchro: Red blind vs sensitive to full visible spectrum. OrthoPan is the middle point.
I consider with Ortho look the emulsions with Erytrosine sensitization dye. OrthoPan those with Pinaverdol. Panchro those with Pinacyanol (full red sensitive) and some Pinaverdol to get also good green sensibility.
Fuji Neopan Acros say in the data sheet it's Orthopanchromatic, page 1, section 4
http://www.foto-r3.com/files/acros.pdf
Note that 2017 marketed emulsions also use other sensitizing dyes, some secret, discovered for color film manufacturing.
IMHO, it's a well stablished photographic term, I ignore if there is a technical definition, nm based.
Recently I've discovered all that because I'm engaging dry plate, and I'm troubled by trying to obtain relatively good emulsion.
A lot of fun
Regards.
It looks that John Sexton says that TMX is designed to need less the yellow filter, but he does not say why.
Perhaps UV blocking feature of TMX removes the sunlight UV effect, and for this reason needs less the yellow filter.
This UV blocking feature is bad for UV alternative printing, but may have the benefit of not needing an UV filter, and less need of a yellow.
But it would be important to know if UV blocking is made in the emulsion or in the base. If not made in the emulsion then my theory is wrong.
[When I can I'll test that, I'll remove the emulsion and I'll see if UV blocking is still there...
Pere:
In the original tech sheets Kodak indicated the TMax emulsions were designed to have slightly less blue sensitivity than other panchromatic films, in order to more closely approximate the sensitivity of the eye. This has nothing to do with the UV attenuating dyes which were/are on the film base.
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