exposure question

Archived from groups: rec.photo.digital (More info?)

Mark Lauter <available_upon_request@just_ask_in_a_post.com> wrote:

> I was just reading this:
> http://www.luminous-landscape.com/ [...] ight.shtml
>
> And the last paragraph is from a comment on the article by Bruce Lindbloom.
>
> "Because of this difference, setting up the exposure using an 18% gray card
> (as is typically done with film) does not work so well with a digital
> camera. You will get better results if you set your exposure such that the
> whitest white in the scene comes close to, but not quite reaching, the full
> digital scale (255 for 8-bit capture, 65535 for 16-bit capture). Base the
> exposure on the highlight for a digital camera, and a mid-tone (e.g. 18%
> gray card) for a film camera."
>
> What I don't exactly understand is *how* to expose for the highlight and put
> it in the top zone. If the camera had a histogram available before taking
> the shot I guess I could just look at that, but DSLRs can't provide a
> histogram until after the shot.
>
> Is this something like Ansel's Zone system? Do you just meter the
> highlights and bump up 2 stops?

Or quarter the shutter speed or ISO, or some combination thereof.

You'd use a spot meter, find the highlight, expose for it, and then
somehow lose two stops'-worth of light. Or more, or less, depending on
the dynamic range of the sensor. Your meter wants to show you 18%, and
you'd want to turn that 18% into something that reflects the 100% of the
highlight.

...if you were trying to expose right. :-) This is bad advice if you're
not trying to expose right.

It would be nice if there were a way to tell the camera this is what you
were doing. You could give it the real midtone of the scene, and then
the highlight, and it would expose right for you and store the offset to
the true midtone in the RAW file for later processing.

Archived from groups: rec.photo.digital (More info?)

"Paul Mitchum" <usenet@mile23.c0m> wrote:
>
> I can't believe I got this backwards.

It is _SOOOOOOOOOOOOO_ easy to get it backwards: I'm terrified to hit the
send button every time I write something about zone exposure metering<g>.

> Meter the highlight, then *add* two stops'-worth of light, just as you'd
> add to 18% to get to 100%. So, for example, set at f/16, meter
> highlight, open to f/8, shoot. Check histogram. Adjust and repeat if
> necessary.

That's it. (I thing<g>.)

David J. Littleboy
Tokyo, Japan

Archived from groups: rec.photo.digital (More info?)

"Mark Lauter" <available_upon_request@just_ask_in_a_post.com> writes:

> I was just reading this:
> http://www.luminous-landscape.com/ [...] ight.shtml
>
> And the last paragraph is from a comment on the article by Bruce Lindbloom.
>
> "Because of this difference, setting up the exposure using an 18% gray card
> (as is typically done with film) does not work so well with a digital
> camera. You will get better results if you set your exposure such that the
> whitest white in the scene comes close to, but not quite reaching, the full
> digital scale (255 for 8-bit capture, 65535 for 16-bit capture). Base the
> exposure on the highlight for a digital camera, and a mid-tone (e.g. 18%
> gray card) for a film camera."
>
> What I don't exactly understand is *how* to expose for the highlight and put
> it in the top zone. If the camera had a histogram available before taking
> the shot I guess I could just look at that, but DSLRs can't provide a
> histogram until after the shot.

Take the picture, look at the histogram, and retake as needed.

> Is this something like Ansel's Zone system? Do you just meter the
> highlights and bump up 2 stops?

No. He's not advocating putting middle-grey at zone 7; he's
advocating putting the *top* highlight values around zone 9. How to
cause that to happen -- depends on the scene and how you meter.
--
David Dyer-Bennet, <mailtod-b@dd-b.net>, <http://www.dd-b.net/dd-b/>
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Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <http://dragaera.info/>