Leica User Forum - View Single Post - Exposure Latitude Question -- Tri-X v. T-grain films

R.Morrison · 05/08/08, 12:14 AM

Mark & PTB:

I was repeating information gleaned from a number of articles printed in photographic magazines. As a journalist, I more than any one, should be aware that all printed word is not gospel and so I have decided to go to the horse's mouth...Kodak.
Perusing technical data publications F4016, F4017, and F4018 I have found that Kodak claim that a one-stop over or under exposure for T-MAX, TRI-X and PLUS-X requires only normal development however when the HD curves for T-MAX 400 and TRI-X are compared it can be seen that T-MAX has a much steeper curve starting earlier and finishing later thus indicating that T-MAX should have a somewhat greater latitude than TRI-X.
The characteristic curves for T-MAX 100 and PLUS-X are not quite so disparate if both were developed on D76 but when T-MAX was developed in its dedicated developer a much steeper curve resulted.
It was stated in F4016 that pebble-like grains are reshaped into tabular form thus producing greater surface area to light. I don't know if this means that the older films like TRI-X have pebble-like grains or not. Publication F-4017 makes reference to old and new versions of TRI-X.
It was instructive also to note that F-4016 (page 14) states that T-MAX has slightly less blue sensitivity than that of other Kodak panchromatic B&W films. This might account for the tone difference between T-MAX and TRI-X or PLUS-X.
Finally, why have I muddied the waters further by introducing discussion of T-MAX 100 (ASA 100) and PLUS-X (ASA 125)? Because PTB, you indicated that fine grain was desired. I would like to remind you that it is a Leica you are using and that you can shoot at very low shutter speeds indeed. I regularly shoot at 1/15 and 1/8 using PLUS-X. Consider the slower films. That said, I hope you do take some T-MAX 400 with you on your vacation because I want to be informed as to how the new emulsion T-MAX films perform as to latitude and especially tonality. Presently, I haven't been able to obtain any of the new emulsion T-MAX in the Ottawa area because the dealers still have plenty of the old stuff or have stopped stocking Kodak preferring to carry Ilford exclusively.

I'll look forward to hearing from you,
R. Morrison, M4-P, etc.

05/08/08, 12:14 AM	#6 (permalink)
R.Morrison Benutzer Join Date: 09/04/06 Location: Iqaluit Posts: 97	Re: Exposure Latitude Question -- Tri-X v. T-grain films Mark & PTB: I was repeating information gleaned from a number of articles printed in photographic magazines. As a journalist, I more than any one, should be aware that all printed word is not gospel and so I have decided to go to the horse's mouth...Kodak. Perusing technical data publications F4016, F4017, and F4018 I have found that Kodak claim that a one-stop over or under exposure for T-MAX, TRI-X and PLUS-X requires only normal development however when the HD curves for T-MAX 400 and TRI-X are compared it can be seen that T-MAX has a much steeper curve starting earlier and finishing later thus indicating that T-MAX should have a somewhat greater latitude than TRI-X. The characteristic curves for T-MAX 100 and PLUS-X are not quite so disparate if both were developed on D76 but when T-MAX was developed in its dedicated developer a much steeper curve resulted. It was stated in F4016 that pebble-like grains are reshaped into tabular form thus producing greater surface area to light. I don't know if this means that the older films like TRI-X have pebble-like grains or not. Publication F-4017 makes reference to old and new versions of TRI-X. It was instructive also to note that F-4016 (page 14) states that T-MAX has slightly less blue sensitivity than that of other Kodak panchromatic B&W films. This might account for the tone difference between T-MAX and TRI-X or PLUS-X. Finally, why have I muddied the waters further by introducing discussion of T-MAX 100 (ASA 100) and PLUS-X (ASA 125)? Because PTB, you indicated that fine grain was desired. I would like to remind you that it is a Leica you are using and that you can shoot at very low shutter speeds indeed. I regularly shoot at 1/15 and 1/8 using PLUS-X. Consider the slower films. That said, I hope you do take some T-MAX 400 with you on your vacation because I want to be informed as to how the new emulsion T-MAX films perform as to latitude and especially tonality. Presently, I haven't been able to obtain any of the new emulsion T-MAX in the Ottawa area because the dealers still have plenty of the old stuff or have stopped stocking Kodak preferring to carry Ilford exclusively. I'll look forward to hearing from you, R. Morrison, M4-P, etc.