Exposure compensation and zone system - am I thinking correctly?

[jeffreyg]

tkamiya,
You are not correct as eddie has mentioned. Your spot meter is reading reflected light off your subject. The meter 'believes" that it is reading off an 18% reflective surface so depending on the reflective property of your subjects skin it will want to place it accordingly. Invest in a gray card and do some reading on the zone system. Shifting zones can also involve modifying development time.

[tkamiya]

Um.... but, but, but... eddie said I was correct in his last update...

Can you tell me exactly, please, why you think my logic is incorrect? (and I did misstate the zone number. I want zone 6, not 4). Thank you.

Yes, I do have a gray card.

[eddie]

Once you realized you wanted a zone VI placement, your logic was correct.
If you decide to use a gray card for metering, you will not need to compensate for the exposure.

[tkamiya]

Thank you again, Eddie.

[jeffreyg]

You can take a reading off the gray card held in front of the subject's face and then one off the subject and compare to see what zone their face actually is in. Setting your exposure to that of the gray card reading should give you a correct exposure. Does your subject have light or dark skin? I assume you are using B&W film ? That will have decent latitude so if you are off a little you can compensate in printing. These answers are brief but there are many books on the zone system. Once you get comfortable with it you should be able to judge what zone areas of your composition fall in. An incident light meter will read the light falling on your subject.

[eddie]

I'd still recommend doing it manually.

[tkamiya]

Gentlemen,

As I said in initial post, this is more of a thought exercise for me to see if I understand the zone system clearly enough to apply it to the real-life situations. I do own a light meter, gray card, and a camera with manual capability. Thanks again for helping me think this through.

Taka

[jeffreyg]

Personally I use a Pentax 1degree spot meter and always carry a gray card just in case. I found an acrylic gray card and cut it into a convenient size. It has lasted for many years. Calumet may still carry them. I have one in reserve for when i happen to lose it.

http://www.jeffreyglasser.com/

[Robert Budding]

Metering off of a gray card is the same as taking an incident reading. I spot meter because I don't always want mid-tones to fall on Zone V during exposure. I may, however, adjust development so they end up there on the developed negative.

[RalphLambrecht]

I think tkamiya has it correct now, just as eddie suggested.

eddie
Opening the aperture for exposure correction may help in explaining it to students, but it has the disadvantage over time corrections that it changes the image's depth of field. Hence, exposure corrections through shutter timing adjustments are preferred, because they do not alter the image.

jeffreyg
If one is interested in a realistic rendering, the use of a Gray Card is a great option if an incident meter is not available. However, zone placement as described by tkamiya is a valid Zone System strategy and goes to the heart of visualization.