TXP and zonal system

ginoross · Mar 8, 2006

Hi there, I'm tying to use the zonal system following St. Ansel directions.
The film that I'm using is tri-x 320 and the developer is Hc 110 1-29 for about 7 min at 20°C.
My problem is that I can find the density 0,10 in the zone 1 around when it is exposed at iso 500/640 when I expect it around iso 250.
I've tried two different emulsions and the results are almost the same.
Can anyone help me?
Thanks in advance
gino

SoulSurround · Mar 8, 2006

ginoross said:
Hi there, I'm tying to use the zonal system following St. Ansel directions.
The film that I'm using is tri-x 320 and the developer is Hc 110 1-29 for about 7 min at 20°C.
My problem is that I can find the density 0,10 in the zone 1 around when it is exposed at iso 500/640 when I expect it around iso 250.
I've tried two different emulsions and the results are almost the same.
Can anyone help me?
Thanks in advance
gino

Do you use a proper densitometer or for example the Heiland Splitgrade? The latter is less precise in the lower densities.

ginoross · Mar 8, 2006

I have a TOBIAS TB+ and a X-Rite 341 and the results are almost the same

Marc Leest · Mar 8, 2006

Could it be your lightmeter being a little bit off ..?

KenM · Mar 8, 2006

Could it be that how you're exposing your film is the issue? If the shutter speed is slow, you could see the effect you're seeing now. BTW, I dilute HC110 1:11 from stock and develop for 6.5 minutes in tanks and hangers for 4x5. My rated speed is 160.

BTW, while 0.10 is the 'standard' for determining film speed, but I would use 0.15 to make sure that your shadow detail is recorded off the toe of the film.

Lastly, Tri-X in HC110 will give you an upswept curve shape, so technically the entire film is 'toe'....

ginoross · Mar 8, 2006

for my test I use a fuji 680 whith an electronic shutter and a minolta spotmeter F
I process the film in a Jobo CPA 2
thanks a lot
gino

jeroldharter · Mar 8, 2006

Your results illustrate the point of testing in the first place. You might want to repeat the test to confirm, but go with the data.

ginoross · Mar 9, 2006

I dit it several time with different stoks of TXP 320
thanks
gino

KenM · Mar 9, 2006

So, I would suggest that something if 'off' - however, as long as you use all the same tools to make photographs, it doesn't really matter does it?

You've discovered why it's important to do at least a wee bit of testing (either exposing step wedges or scenics) to get a grip on what your film speed is.

haziz · Mar 9, 2006

ginoross said:
Hi there, I'm tying to use the zonal system following St. Ansel directions.
The film that I'm using is tri-x 320 and the developer is Hc 110 1-29 for about 7 min at 20°C.
My problem is that I can find the density 0,10 in the zone 1 around when it is exposed at iso 500/640 when I expect it around iso 250.
I've tried two different emulsions and the results are almost the same.
Can anyone help me?
Thanks in advance
gino

You may want to run the test again just to make sure but you likely did in fact find the film speed based on your metering, exposure and developing technique. Once you are relatively satisfied with your test just shoot some film and check if you have good shadow detail. Many people do get higher than "box speed" results on their film test. I have personally tested FP4+ at 200-250 in three different developers (Sprint developer, Xtol and DDX diluted 1:9) even though the box speed is 125. Acros has however tested at 50 in DDX 1:7 and 80 in Rodinal 1:50 and HP5+ tested a slightly surprising 250 in Xtol though I may want to run the latter test again just in case.

Sincerely,

Hany.

TXP and zonal system

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