Question on autofocus

[maxmasa31]

I just got a replacement unit after receiving one with a bad sensor and, maybe it's my imagination, but the autofocus on my new GRD4 doesn't seem as responsive as on the one I returned.

When I focus on a subject (using Spot and Multi AF), even if the subject is already in focus, the camera will always refocus before locking and at times, I've gotten an orange warning about the focus not locking if I try to jump between subjects too quickly. I've tried it with "Pre-AF" off and on, but it still always refocuses on a half shutter press, even if I'm focusing on the same subject repeatedly. In fact, having Pre-AF activated doesn't seem to help with AF speed much at all because it keeps needing to refocus all the time.

Full snap focus also doesn't seem to work properly. When I do a full press snap, it seems to always focus at 1m, regardless of what distance I've preset (I've tried them all).

I recall the first GRD4 I got being more responsive in regards to focusing, but maybe it's just my imagination. Should I try changing some settings?

 

[Blow-in]

I don't have this problem...

I'm normally using:

Focus : Multi AF
Snap Focus Distance: Auto
Full Press Snap: On
Pre-AF: Off
AF Auxiliary Light: Off

Richard

 

[Blow-in]

Just another thought... if you are using 'A' make sure that the macro is off.

Richard

 

[maxmasa31]

Thanks for the info Richard.

It's not the macro setting, as I've tried all varieties of shots, both with the macro on and off, but I still experience the same thing. I usually shoot in Aperture priority and use Spot AF, and have tried all sorts of combinations of modes (Program, Auto, Shutter priority with Multi or Spot AF and Pre-AF on/off) and all produce the same result: Refocus before lock on half shutter. No matter if it's the exact same subject two seconds apart, if I half-press, it will ALWAYS refocus before it locks. On more than one occasion, if I'm quickly changing subjects, it will misfocus due to the constant refocusing, resulting in a blurry image.

I also thought it could be due to lighting conditions, but regardless of whether it's a dim room or outdoors in the early afternoon, the camera keeps refocusing, even if the subject is initially already in focus.

I REALLY like the GRD4, but I've apparently gotten two lemons. I'm returning this second one to Amazon and buying from an actual camera shop. Hopefully I'll get one with the AF of the first unit I got with the working sensor of the second... Third time's a charm, right?