Exposure index on Leica M7

[stephen_persky]

Hello,

 

I have been reading about setting your own custom exposure index

for "your equipment" and "film". I was wondering if anyone has

figured out and exposure index for contrasting daylight shooting with

Tri-x film through a Leica M7.

 

thanks

[working camera]

Stephen

 

The EI for any film is very much dependant on how it is developed. The juice used,

dilution, time, temperature and agitation all must be standardised. Probably the best

source for the procedures is Ansel Adams �The Negative�. Assuming all are calibrated

correctly, which camera or light meter used is not an important factor.

 

Having access to a transmission densitometer is also essential for correctly setting

your own EI.

 

This said, a lot of people standardise their Tri-X on an EI on ISO 360.

 

Craig

[gil garcia]

Try Tmax at 320 and ilford xp2 super at 250.

gg

[mikey_campbell]

Stephen,

I have found that the exposure index can be different for every camera,

whether it is between a Nikon and a Canon, or two same-model Leicas. A

simple test as to what your specific camera can be conducted, that is if you

are in control of all aspects of exposure, including development. I agree that

developing is a very imporant aspect of exposure, and as such should be

considered as well as printing. To me, development is one of the most

important things to concentrate on during post-exposure processing. After you

find out your exposure and calibrate accordingly, make sure you are

consistent with your processing procedure. Of course black and white offers a

bit more latitude in the way of processing when compared to color, but still,

you should be careful. If you want to, I can help you out with the testing

process and calibration. Just drop me an e-mail. Good Luck.

[skeeter]

assuming you are going to let your m7 read your tri-x at asa 400, you would want to set the exposure compensation dial in the plus range. ansel adams says in his book he generally liked to overexpose by 1/3 stop more than what the light meters he used suggested was the correct exposure. this can be accomplished by setting your index to + 1/3 stop. i personally think this is easier than setting the film speed to 360. this also gives you the latitude to vary the ev compensation depending on the subject you are shooting. i agree with others that uniform processing is crucial for the above adjustments to make a reliably significant difference. i actually think 1/3 stop is rather puny, and would suggest more. another way to boost contrast (if i am reading your goal correctly) is to use a filter.

[i._g.]

I think if you want to increase contrast, you'll have to use an EI HIGHER than 400 and develop more than what you would develop for EI 400.

 

That's not my favorite way of using this film, but if higher contrast is what you're looking for... (I use EI 200 and develop for 9 minutes in D76 1+1 at 20 deg centigrade)

[octavio bustard]

I never really understood the advantage of changing the ISO from its rated speed. I shot my TX at 400 and develop for 400.

 

What differences do you see when exposed and developed at 320 or lower?

[i._g.]

I find I've got more information recorded on the film, like detail in shadows and detail in highlights.

 

I guess you can expose at 400 and get beautiful results, but if you make a mistake and underexpose, you lose shadows (if you overexpose it's not that bad). By exposing at lower EI, I leave myself some room for error on both directions...