i have 10 deg. spot meter attachment for my hand-held meter. what lens is the equiv. (200mm?). i don't have a lens chart handy?

and, what materials below are or are not 15-18% reflectance?

grass, foilage

sand

limestone

caucasian skin, my palm

asphalt

concrete

more?

-- steve (leitz_not_leica@hotmail.com), June 07, 2002

Answers

Steve, I don't have anything handy either, but a 90mm has a 27 degree diagonal. So a 180 would be around 13 degrees; and thus, 10 degrees should be a pretty good approximation for 200mm.

Grass is often a good zone 5 or 18% reference point. Asphalt can be, but only if it's weathered just right. Caucasian skin is zone 6, often; one stop brighter than the mid-point. The other stuff you mention is way lighter.

-- Bob Fleischman (RFXMAIL@prodigy.net), June 07, 2002.

Here are the ones I'm familiar with:

Grass: can be pretty close to 18% grey. But it depends on the shade of green. I find it wirks well enough for b/w

snad/snow: figure on opening up 2 stops.

palm of your hand: depending on your skin tone, open up one stop.

grey concrete: open up one stop usually

black asphalt: stop down one or two stops

-- Josh Root (rootj@att.net), June 07, 2002.

Watch out for grass, it is sometimes very shiny, about a +2/3.

-- Jay (infinitydt@aol.com), June 07, 2002.

I was to answer but I've seen it was already answered.

Just a detail: Why do you want to know? I mean, I tend to trust the cell and I try to reproduce the variation of tones.

For instance, I use Slide Film and I know the reproduction covers 2.5 ev. In the image, I try to ponderate the darkest against the lightest (mind you, the fuzzy logic of Nikon is doing that 10 times better than me). Then I choose a value or a couple and take a few photos.

Result can be okay (with the CL or the Minox), excellent (usually with the R7).

But the point is, although the cell is calibrated, photography is about how to reproduce a scene with a limitation of the chemicals.

If I'm wrong just flame me, very hot, please. Xavier

-- Xavier d'Alfort (hot_billexf@hotmail.com), June 07, 2002.

Thanks, Steve, for asking that question. Thanks to everyone else for answering it. Just what I needed!

-- Ray Moth (ray_moth@yahoo.com), June 09, 2002.

To all

What is with middle grey (zone 5) being 18 per cent? Looking at a spray of tones from paper clear white to full black, it seems the mid point would be 50%. If fact it seemed to be last time I looked...

Perhaps this is just a minor mystery...

-- Larry Welker (lwelker@adelphia.net), June 10, 2002.