# correct exposure to get a Zone VIII negative

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• 07-25-2012, 07:57 PM
Jose A Martinez
correct exposure to get a Zone VIII negative
I'm working with a panoramic pinhole Holga and I want to know if I'm on the right path to expose a negative in zone VIII to determine the development time and know if I'm getting the proper density.

I take the reading of the exposure meter against a flat even surface, a piece of gray cardboard, and make four shoots the length of time the mesure I got, I'm right?
• 07-25-2012, 09:21 PM
The exposure meter gives you the exposure for Zone V, so you would open up three stops from the indicated exposure to get to Zone VIII.

That's assuming you know the proper exposure index (EI) to use for your film (and to set on your meter), which is oftentimes not the same as the one on the side of the box the film came in.
• 07-25-2012, 11:50 PM
Mainecoonmaniac
I think development is part of the equation. Zone VIII is highlight without detail. Expose for shadows develop for highlights as they say.
• 07-26-2012, 05:45 AM
RalphLambrecht
sounds alright. i look for zone viiito develop to a density of 1.29.
• 07-26-2012, 09:01 AM
Jose A Martinez
Quote:

The exposure meter gives you the exposure for Zone V, so you would open up three stops from the indicated exposure to get to Zone VIII.

That's assuming you know the proper exposure index (EI) to use for your film (and to set on your meter), which is oftentimes not the same as the one on the side of the box the film came in.

Ok, the thing is that I'm testing for a pinhole camera, so instead of open up three stops I have to expose three times the exposure meters' time indicated, right?
• 07-26-2012, 09:30 AM
jnanian
hi jose

it wouldn't be 3 times but you would double your meter reading for each zone/ fstop ...
.
for example if it said 1 second ... it would be ..2 ( 1 stop/zone), 4(2stops/zones) ... 8 seconds for 3 stops/zones

sounds like a fun project !

john
• 07-26-2012, 10:04 AM
Jose A Martinez
Quote:

Originally Posted by jnanian
hi jose

it wouldn't be 3 times but you would double your meter reading for each zone/ fstop ...
.
for example if it said 1 second ... it would be ..2 ( 1 stop/zone), 4(2stops/zones) ... 8 seconds for 3 stops/zones

sounds like a fun project !

john

so the progression is geometric, not arithmetic.
• 07-26-2012, 10:08 AM
Bill Burk
Jose A Martinez,

We haven't mentioned "reciprocity law failure" which means you may need to give even longer times if you are running into exposures longer than 10 seconds since you are using a pinhole...

An old chart says it:

If indicated time is ... give this much time

1 sec ... 2 sec
10 sec ... 50 sec
100 sec ... 1200 sec

---
Curiously, it is about the same as placing exposure on Zone VIII ... I wonder ...

Is the whole purpose of moving exposure to Zone VIII supposed to correct for reciprocity law failure?
• 07-26-2012, 10:08 AM
polyglot
Quote:

Originally Posted by Jose A Martinez
so the progression is geometric, not arithmetic.

Correct. Exposure factor = 2 ^ stops.
• 07-26-2012, 10:09 AM
Bill Burk
Quote:

Originally Posted by Jose A Martinez
so the progression is geometric, not arithmetic.

Yes
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