I am after some advice about the best way to nail focus in low-light situations (stemming from another thread that I was on and didn’t want to take OT!).
I’ve been spending a lot of time over at local zoo’s and wildlife parks, and I am particularly enjoying the reptile areas. I’ve had some success in the past with decent shots, but my most recent visit ended up with disappointment and a vast majority of out of focus pictures. The problem I had is that the pictures looked fine on the viewscreen after taking them and I thought I’d nailed it. It was only when I got home and put them onto the PC that I realised that most of them were garbage. I am sure there must be some specific technique or camera setting that I am missing, but I have been trawling other posts, photography guides, my camera manual etc etc and I can’t quite pinpoint where it went wrong. One of the suggestions from the other thread that I am on was that I need to be using a relatively fast shutter-speed to maintain focus, and looking at most of my pictures they varied about 1/4 , 1/6, 1/10 etc … so definitely slow! But this was in a low-light environment where flashes aren’t allowed and I was already pushing the “noise-limit” with 1600 ISO.
Here are some examples of what I got. These looked great on the viewscreen, but as you can see, once you get them onto the PC you can see the focus is totally off (it's obviously much more noticeable on the full sized images):
The setup I was using for the day was as follows (from what I can remember):
Sigma 70-300 DG Macro F5.6
Camera in AV mode set to F5.6
Spot-Focus (using middle-marker to focus on subject’s eyes)
Servo AI focus
Centre Weighted metering mode
A lot of the shots were taken at full 300mm zoom with the “Macro” switch turned on (without it the focus wouldn’t “reach” far enough to find the subject).
So is there some technique I am missing, or some “eureka” setting that will solve my issue. If I really do need a faster shutter speed, then how can I do this without pushing the ISO crazy-high and getting noisy images. Is it a limitation of my Lens or Camera itself that needs to be changed?
Any advice would be great .. I'm planning more trips