View single post by GeoffR
 Posted: Sat May 1st, 2021 09:22
GeoffR

 

Joined: Thu Apr 12th, 2012
Location: Denham, United Kingdom
Posts: 267
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May I put this another way?
The light falling on a subject is not affected by the colour, reflectivity or any other property of the subject.
The light reflected by the subject is affected by all these things.

An example a black cat on a dark background. The light falling on the cat suggests an exposure of 1/250 at f8 the camera suggests 1/60 at f8. Now replace the cat with a white one, the incident reading remains 1/250 at f8 the camera suggests 1/1000 at f8.

Use the camera readings and you get a grey cat on a grey background or a grey cat on a very dark background. Use the incident readings and the cats come out the correct shade, black or white.

The thing is that none of these exposures is "correct" but one of them will achieve the desired result.