difference between Tri-x 320 and 400?

[stradibarrius]

What is the difference between Tri-X 320 and 400? It seems odd that when Kodak released these two that the only difference would be in the ISO...
I know Tri-X is a tried and true film and many of you have vast amounts of experience with these two films.

 

[rwboyer]

They are both wonderful for a lot of different reasons. TX (400) has a strait curve in the middle tones with a long slow shoulder in the highlights - this effectively reduces highlight contrast while giving the lower mid-tones and mid-tones "snap" - easy to print but highlight separation can suffer.

TXP (320) has a very very long toe - well into the mid tones that straitens out in the upper mids and highlights - it is exactly reverse of TX 400 giving you somewhat depressed mid tones and shadows with less contrast while separating highlights extremely well. This may make it harder for the beginning darkroom worker to expose-process and print well but when done "right" it has exceptional highlights. TXP also has smoother grain than TX400 - Try them out they are both fantastic but TXP will probably take more dialing in on your part to achieve what you are going for - that being said you can achieve very very different effects with TXP just based on where you place tonal values during exposure. I love TXP for some things like high key female portraits where I am placing a lot of the skin tones in VII VIII and even IX. In high key work TXP can be made to behave like a much slower film due to it's highlight separation.

RB

This is PXP but I did a side by side comparison of the same exact scene after having known both films for a long time and you cannot tell one print from the other. I don't have a scan handy for the TXP of the same scene but like I said the prints are identical - Highlight rendering with TX400 would be substantially different in this case.

 

[stradibarrius]

WOW...What a nice shot. This girl has a moviestar face and eye!!! Not over looking her other nice features as well.

 

[rwboyer]

WOW...What a nice shot. This girl has a moviestar face and eye!!! Not over looking her other nice features as well.

Thanks - as always a digital web image is difficult to evaluate vs a print but the point is that I think TXP is especially wonderful for rendering high key studies in white where almost the entire print is made up of subtle variations of very high values TX400 would make it a lot more difficult to separate the subtle skin tones on the face, the whites of the eyes and the catchlight - typically with TX400 they would be closer together at grade 2 or even 3 developed to the same overall CI than TXP. On the flip side - TXP can look horrible if you do not place skin tone values high enough and there are a lot of whites in the scene that you wish to render detail in.

RB

 

[BetterSense]

is especially wonderful for rendering high key studies in white where almost the entire print is made up of subtle variations of very high values TX400 would make it a lot more difficult to separate the subtle skin tones on the face, the whites of the eyes and the catchlight

It seems like you could achieve a similar effect with TX400 by underexposing a couple stops. I know I have had great luck with portraits shooting hp5+ at 1600; it honestly looks better than when 'properly' exposed.

 

[rwboyer]

It seems like you could achieve a similar effect with TX400 by underexposing a couple stops. I know I have had great luck with portraits shooting hp5+ at 1600; it honestly looks better than when 'properly' exposed.

It's all about subtle effects - of course you can get separation via a contrast expansion but that creates other effects as well Like increased separation everywhere - that's okay, just different. One of the wonderful things about BW and BW materials is the subtle differences in effect that can be had. The art of it is in the choice and how that choice "works" for what you are doing.

RB