Photons Missing In Action

Started Nov 24, 2009 | Discussions thread
JP Scherrer
JP Scherrer Forum Pro • Posts: 10,640
@ Jim Keye

Jim Keye wrote:

Why would the need to apply positive exposure compensation suggest the lens is brighter than advertised? If anything, it suggests your subject is brighter than middle gray.

It seems to suggest the lens is 2/3s of a stop slower than advertised, regardless of subject.

Ooops ! I corrected it: of course it was MINUS 0.7 EV !!! ...which make the lens brighter than f/4 !

Why would the need to apply positive exposure compensation suggest the lens is brighter than advertised? If anything, it suggests your subject is brighter than middle gray.

Well...not always. First, sometimes metering is done externally. Also, there are a great many instances when people use manual exposure. When you switch lenses you have to change exposure also. Sort of a PITA when you're in a hurry, not to mention you have to decide between changing ISO, shutter, and f-stop to achieve the correct exposure again. Each affect things differently, especially if you're using a flash or a flash-ambient mixture, have the flash set on manual mode, etc. etc.

I tried all possible arrangments: apertures, shutter-speed, different subjects vs background/foreground lighting, S-mode, A-mode, M-mode, you name it ! Everytime the image was correct with -0.7 EV !

Still wondering... and enjoying !


J-P.

Photo Galeries at http://www.pbase.com/scherrer - Spherical Panoramas (360x180°) at http://www.360cities.net/profile/jps
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 JP Scherrer's gear list:JP Scherrer's gear list
Nikon 1 V1 Nikon 1 J1 Nikon D810 Nikon AF DX Fisheye-Nikkor 10.5mm f/2.8G ED Nikon AF-S Micro-Nikkor 105mm F2.8G IF-ED VR +7 more
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