How to use a 18% Grey Card with Reflected LIGHT Meter.

Good examples joe, thanks.

The Zone System is nothing more than a tool to let you get a scene recorded on film with some sensible exposure, and development consistent with the contrast range. The resulting negs should then print with minimal pain and grief on standard grades of paper. There was a time when both film and paper curves had useful toes and shoulders, allowing one to have both shadow and highlight detail, while still maintaining sufficient contrast in the midtones to produce a brilliant print. I think those days have been gone since the '70s. Regardless, one way or another, you usually have to get a much wider range of brightness mapped onto paper that most certainly doesn't come close to 144% reflectivity! Minor White also wrote a book on the Zone System, which I'd suggest avoiding like the plague. Though maybe a bit hard core, one of the best books for people that really want to understand this stuff is Photographic Sensitometry, The Study of Tone Reproduction, by the late Hollis N. Todd and Richard D. Zakia. I may be a bit biased as Todd was one of my instructors at RIT.

The point I was driving at is: If, after years of using his own system (presumably) and banging on about the importance of correct exposure, Saint Ansel could make a very fundamental error, then how important is accurate exposure really?

 

We use a logarithmic system based on doubling or halving the amount of light with every stop. That's a ridiculously sloppy tolerance by any standard. And yet people worry about putting a 1.5 v cell in a meter designed for 1.35 v and suchlike nonsense.

 

Let's get a sense of proportion and stop worrying about measurement precision that makes no practical difference.

I'm a measurement geek, and in my electronic work anything worse than a few parts per million isn't even interesting. For photo, not so much. It always amazed me that film makers got the consistency they did. All that black art of ripening and such. Great accuracy just isn't inherent in the process, though I can say from experience that a systematic problem like a light meter reading a stop too high will trash your work until you figure it out. IMO, everybody should do a ring-around at some point just to make sure they're somewhere near the sweet spot. I see a lot of technically bad b&w work, but without the broad knowledge base we used to have, much of it is just accepted as normal.