Originally posted by betaPhoto Can your K-5 focus accurately with the following parameters:
* EV2 & EV3 area (as well as EV 8 or so for accuracy comparison) (EV1-EV4 is sighted as the main trouble).
* The focus distance should be between 2 and 5 feet (.5-1.5 meters) where the problem is quite pronounced.
* The f-stop should be f2.0 to f2.8.
If it can, show people some shots of it. End the hysteria by showing the K-5 can be capable of low light focus accuracy!
I have done testing in atrocious lighting (~EV 0.7), very warm white fluorescent, f/2.8, near macro focus distance (DOF ~1mm). The camera had a very hard time finding focus at all, and only by targeting a high contrast transition did it lock. No one in their right mind would ever shoot like this. And yes, I physically blocked the AF assist light (for some reason it would refuse to lock if I just disabled it, so I left it on and blocked it). The target was also mostly shaded from any direct light from any source (to produce the ridiculously dark conditions).
The test produced...
back focus by about 2-3mm. My other macro lens produces very slight front focus (corrected by -2). It looks very similar in EV 5 indirect overcast sunlight (maybe very slightly less pronounced, but still back focused). The same with my original K-5 body, where most of my lenses produced noticeable back focus. None of the lenses required more than +-3 AF correction.
I am very aware of the problems my cameras have had (both my original and replacement K-5s suffer from bounce flash overexposure, the first one had stains, and my K-x has severe shutter blur/mirror slap at 1/100s), and have dealt with people acting like I don't know what I'm doing. Low light FF is not one of these problems.