A thought: Why can't camera and film manufacturer's just consistently tell
the truth?
This is like buying lumber and discovering 2X4's aren't 2x4's. They're not.
They are 2x4's before they are milled. Not after.
Tom C.
----- Original Message -----
From: "Bucky" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, July 12, 2001 11:31 PM
Subject: RE: 18% Gray (again)
> Tom, your explanation differs with what I have read in many places. For
> example, Burian and Caputo, in the National Geographic Photography Field
> Guide (p. 137), write:
>
> "Scientific studies now indicate that an average scene actually reflects
13%
> (not 18%) of the light that falls on it. For the sake of consistency,
grey
> cards have continued to be 18 percent grey, as is the one in this book.
> When using any 18% grey card for substitute metering, increase exposure by
a
> half stop."
>
> Your explanation of the way meters are calibrated makes good intuitive
> sense, and, as you say, it's not relevant. However, in your example, a
scene
> of foliage reflects approximately the same amount of light as an 18% grey
> card. This fact can only be used to deduce that the foliage reflects 18%
of
> the light that falls upon it, not that foliage is an "average" scene.
>
> As I have understood things, the 13% standard simply indicates that "they"
> (bless their hearts, whoever they are) have decided that the average
scene,
> whatever that is, actually reflects 13% of the light that falls upon it.
>
> Of course, as long as one knows how to meter, this is all kind of
academic,
> but I am keen to know what the real story is.
>
> Cheers,
>
> Mike
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Tom Rittenhouse
> Sent: July 12, 2001 21:36
> To: [EMAIL PROTECTED]
> Subject: Re: 18% Gray (again)
>
>
> Sorry, I didn't know what I was talking about here. See "Ah
> ha (was 18% gray) for the answer.
> --Tom
>
>
> -
> This message is from the Pentax-Discuss Mail List. To unsubscribe,
> go to http://www.pdml.net and follow the directions. Don't forget to
> visit the Pentax Users' Gallery at http://pug.komkon.org .
>
>
-
This message is from the Pentax-Discuss Mail List. To unsubscribe,
go to http://www.pdml.net and follow the directions. Don't forget to
visit the Pentax Users' Gallery at http://pug.komkon.org .
