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Wiki for TTL-metering for each system?

RickShinRickShin Member
edited November 2013 in flash & lighting
With ambient metering, we pretty much all know how the automatic exposure works - the difference between evaluative (matrix)/center-weighted/spot metering, how they may (or may not) get thrown off by high/low tonal object in the frame, how we should compensate for the difference from the 18% gray that the camera assumes, etc. You switch to a different system and everything pretty much holds - maybe with very slight exception.

On the other hand, TTL metering depends heavily on the system. One system's TTL is quite different from another. Try to answer questions like (1) does the ambient metering method come into play in the flash TTL metering? (2) does the active focus point have weight? (3) does the flash TTL get thrown off by a bright/dark object in the frame?, and your knowledge with your system - even if you were knowledgeable, which is a big if - doesn't carry you over to another system. The manufacturers don't tell us a whole lot about how their flash TTL works. (Why they don't is a big mystery.) Photographers are pretty much left on their own, without a lot of help from the manufacturers.

In light of the situation, I'm thinking of building a Wiki to dissect TTL metering for each system. Do you think enough people will be interested to take part in such collaborative project? Does anybody know a good, free wiki platform for this kind of topic?



  • Neil vNNeil vN Administrator
    This is a tough topic, since this varies with models within any brand, as well.

    eg, the way that TTL BL behaves between the Nikon D100 and Nikon D4 is hugely different.
    Ultimately though, I think this is one of those areas where we have to accept the arcane nature of it, and just know your own specific camera's behavior, by shooting a LOT.

    Making it an academic endeavor listing every camera's behavior for various scenarios, is going to be a disconnect from the actual venture - photographing stuff.
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