Focus Lock 100-400 +30D

[Paul Pearson]

Hi all

The 30D manual states that focus lock only works in One-shot AF mode and not in AI Servo Mode.

I can recall several threads advocating focusing on the bird's eye and then re-composing the image as required before taking the shot. I see from Keith Reeder's web site that he uses AI Servo mode.

I'm sure I've missed something here - whats is the preferred solution?

regards

Paul

[postcardcv]

for a static bird I'd use one shot, focus on the eye and then re-frame for the desired composition... for me however birds tend to be moving around and I don't have the time to do this, so instead I use AI servo, aim on the eye and will then crop for composition if needed.

[Keith Reeder]

What Peter said...

I have to say though, that AI Servo seems to work well enough for static birds too (not that I get many chances there!) - I'm sure that ultimately One-Shot would be better, but AI Servo seems like a very reasonable "all-rounder".

Since I got my 40D I've started using the "AF-On" button to activate AF: that way I can stop and start focus as I see fit, which gives a kind of "pseudo" Focus Lock.

I have to say though that focus and recompose is something I tend not to do - I struggle with it, to be honest.

Instead I usually use the centre AF point, so the bird's generally in the middle of the frame, and do the composition part of the exercise at my PC.

That said, I'm starting to use other AF points a bit more now, again as an alternative to focus and recompose.