I have been testing some cameras, and concluded that there was no question multi zone metering is heavily biased to you AF point on SLR cameras.
Sorry to link to DPreview..but all the info/talk is there..
I hope this is of some use to people...it is hard to get specific technical details, as manufacturers are not keen to disclose the exact workings of their particular system.
I am amazed so few websites mention it....
Any thoughts...fire away!
http://forums.dpreview.com/forums/read.asp...essage=20613063
Some real world results with an explanation of each shot:
http://forums.dpreview.com/forums/read.asp...essage=20615944
And a Nikon D70 owners test result..confirming the same:
http://forums.dpreview.com/forums/read.asp...essage=20618533
Full Version: Multizone metering myths...
I find it funny how folks at dpr seem to always be "discovering" things that I thought were common knowledge (and then depleting a 150 post thread arguing about it). The preference for not only which focus point, but the number of focus points in use, has been documented for years.
complete nine page article
Canon's own documentation at http://www.canon.com/technology/canon_tech...multi_zone.html also clearly states the linkage to AF points. It's even mentioned (albeit minimally) in the manual!
I didn't bother checking to see if there's similar documention of Nikon behaviour, but the clue might be that matrix is disabled with manual focus lenses.
Maybe someone needs to tell folks at dpr about google
In reality, this is what matrix/evaluative metering is all about - trying to determine the subject and relative importance of the various parts of the image. If you don't want this just put it in averaging mode, or do like I do and use your own brain (manual mode) rather than trusting the camera to guess what you want.
- DL
QUOTE
Basically, the EOS 300's 35-zone Evaluative metering system takes into consideration which of its 7 AF points have locked onto the main subject as well as the differences in brightness between the main subject and the background. If more AF points are concentrated on a darker subject than a brighter one, the camera will assume the former as the subject and calculates the settings to give optimum exposure for that picture.
Simultaneously, if you concentrate more of the camera's AF points on a brighter subject, the camera will give preferences over it and less on the darker elements. This is fine if you have concentrated the AF points on the correct subject, otherwise you will end up with overexposed or underexposed pictures. Photo H is an example of how the EOS 300 gave a correct exposure on the mannequin biker despite the brighter elements in the background.
Simultaneously, if you concentrate more of the camera's AF points on a brighter subject, the camera will give preferences over it and less on the darker elements. This is fine if you have concentrated the AF points on the correct subject, otherwise you will end up with overexposed or underexposed pictures. Photo H is an example of how the EOS 300 gave a correct exposure on the mannequin biker despite the brighter elements in the background.
complete nine page article
Canon's own documentation at http://www.canon.com/technology/canon_tech...multi_zone.html also clearly states the linkage to AF points. It's even mentioned (albeit minimally) in the manual!
I didn't bother checking to see if there's similar documention of Nikon behaviour, but the clue might be that matrix is disabled with manual focus lenses.
Maybe someone needs to tell folks at dpr about google
In reality, this is what matrix/evaluative metering is all about - trying to determine the subject and relative importance of the various parts of the image. If you don't want this just put it in averaging mode, or do like I do and use your own brain (manual mode) rather than trusting the camera to guess what you want.
- DL
I agree with Don: I learnt that the metering of my Canon Elan II (EOS-50) is adapted to AF point by reading its manual.
Hopefully I am not contributing to this becoming another 150 post thread!.
Hopefully I am not contributing to this becoming another 150 post thread!.
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