Originally posted by Christine Tham I just realised I should have qualified my statement. I have assumed that all K-5s behave like mine - it may well be that there are K-5s out there that have FF even in situations where mine didn't.
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However, I suspect the issue is also lens related -
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The thing is that some do not suffer from front focus in low artificial (tungsten) light and some do. Whether this means that there are defective and good units out there or that the conditions for this to occur are quite specific (or both or something else altogether
) we don't really know. Like the more general FF/BF issue this could be something that occurs (or not) with the combination of a specific copy the K-5 and the lens used.
Faster lenses, of course, should enable AF to work in murkier conditions as AF is done aperture fully open.
I have had this hamper my use quite a bit as this time of year at least my shooting is mostly confined inside (where the most interesting thing tends to be people
), and much of that is in artificial light. In practice this means using my Tamron 17-50mm 1:2.8 at f=2.8 (typical: ISO 3200 t ~ 1/30 - 1/60) so DOF is kind of narrow; it is annoying to discover that something that would have been very nice otherwise e.g. has the tip of someone's nose in focus and eyes a bit soft, especially so when the k-x did not have similar problems (or in fact made this sort of thing possible for me with its low ISO capability). I guess I could always put in a proper focusing screen and get some more MF lenses and see how that works out, but I'd prefer AF working at least as well as it did with the k-x.
Of course, I might do well to pick some less convenient targets, but that is another matter.