Zone VI Pentax plus a stop?

**Steve Hamley** · 29-Jul-2010, 05:08

Folks,

I tested my Zone VI Pentx spot meter along side my friends meters (professional and advanced amateurs) and noticed that it overexposes by about 1 EV. Now typically I don't pay a lot of attention to such things because meters can vary for a lot of reasons, but the spread was reproducible when metering a gray card in indirect daylight versus the other meters, an in field use.

The reason I ask is that Gordon Hutchings, in "The Book of Pyro" mentions that zone VI meters will overexpose by about a stop, and that looks like what I'm seeing. Anybody else notice this? I also know that Paul Butzi tested a modified versus non-modified Zone VI Pentax digital spot meters and found no difference.

I've also heard - urban legend - that the Zone VI mods were designed for Tri-X, and so one might argue that the mods push the shadow values up the toe a bit, but as far as I can tell, there's absolutely nothing to support this conjecture.

Anyone notice similar behavior with their Zone VI Pentax digital?

Cheers, Steve

**aduncanson** · 29-Jul-2010, 05:24

I casually compared a newly calibrated Weston Master 9 to my Zone VI modded Pentax digital meter and noted the same thing. I figured that that might be why I never saw a reason to underrate my HP5+, but shoot it at 400.

**Bruce Watson** · 29-Jul-2010, 06:10

Meters drift over time. You can always send it to Richard Ritter and have it calibrated if it's bothering you.

**Arthur Nichols** · 29-Jul-2010, 06:30

I had the same issue with my Pentax digital spot meter and had it calibrated at Quality Light Metric. They do work for the film industry. I used to have to expose FP4 at 250 ASA to get correct densities. Now it works perfectly and I shoot FP4 at ASA 125 where it should be. Your light meter should be calibrated so that it corresponds to industry standards. It should not read 1 stop too high.
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**Brian Ellis** · 29-Jul-2010, 07:22

"The reason I ask is that Gordon Hutchings, in "The Book of Pyro" mentions that zone VI meters will overexpose by about a stop . . . "

This is a new one to me, I used a Pentax digital spot meter modified by Zone VI Studios for many years and it was always - how shall I say it? - spot on.

**Jim Noel** · 29-Jul-2010, 08:51

MY Zone VI modified meter has never exhibited this problem. I have other good meters both reflective and incident with which to compare against my standard light source, and it has maintained its accuracy for over 20 years.

**RichardRitter** · 29-Jul-2010, 08:54

Meter do drift. How new is this one to you. Calumet in the 90's for a while were calibration then to a standard that was a stop off. I have a meter that is one stop off and have calibrated it back to the correct setting a few times and got tried of always having to redo it after a day of working with it. It is now one stop off and has stayed there now for five years.

Also the filters sometimes cloud over in the meters and when meters are calibrated by others they don't bother to check the filters and calibrate then with the clouded filter.

**Steve Hamley** · 29-Jul-2010, 09:42

Hi Richard,

The meter is actually on it's way to you today (along with lens boards for adapters) for a checkup and calibration - I mentioned it to you on the phone a few days ago.

I bought the meter used off this forum and it seems in good shape, but all measuring electronics need periodic checks. Because the age and history is unknown, it could well be a stop off "naturally", just need calibrating, or have any number of issues. I can deal with the stop as long as it is linear of course, but the question for me - other than curiosity - is "Is the meter functioning as it should?"

Cheers, Steve