I haven't actually looked at spectral sensitivity information on the two films, but when T-Max came out I found that the same meters that gave me consistently good exposures with old style films gave me good exposures with TMY only in daylight, but gave me considerable underexposure in tungsten. This is significant for me in 35mm, and something I found recently with TMY-2 in 4x5 too - some indoor portraits were underexposed, looks like they could be a whole stop under, but maybe 1/2-1 stop.
Is this something verified in the spectral curves?
I've not had any problems with T-Max films in tungsten lighting. I base my comments on the results that I've gotten and also a couple tidbits in the Kodak spec sheets for T-Max films. The first is obviously looking at the spectral sensitivity curves. T-Max films are different from Tri-X ones. Next up is this note in the T-Max spec sheets (located next to the spectral sensitivity curves):
The blue sensitivity of KODAK PROFESSIONAL T-MAX Films is slightly less than that of other Kodak panchromatic black-and-white films. This enables the response of this film to be closer to the response of the human eye. Therefore, blues may be recorded as slightly darker tones with this filma more natural rendition.
They also state this at the beginning of the document for T-Max:
Virtually no difference between the daylight and tungsten film speeds
Lastly, if you look at the recommended filter factors for T-Max films compared to Tri-X, you'll see that T-Max films need less correction for yellow filters yet more correction for blue filters.
I've heard people say that T-Max's spectral sensitive is like shooting with a built-in yellow filter. I don't know how true that is, but there is certainly a visible difference. The big thing I notice when looking at the spectral sensitivities of Tri-X, Plus-X, and T-Max is the large extension into the UV for Tri-X. Plus-X has relatively steep cutoff, while the curves for T-Max just don't show the UV sensitivity. I've certainly noted the difference between UV/blue sensitivity with Tri-X and Plus-X. I get a lot more white skies with unfiltered Tri-X than I do with Plus-X. I have a hunch that part of the Tri-X look probably has to do with the large blue + UV sensitivity, though I don't really have any empirical evidence for that statement other than the info stated above.


