After my first couple outings with my 40d in the water last month in Moorea, I had a couple questions what you all use as far as focusing method. On land I always select the middle focus point alone. So I focus (half shutter release press) on what I want the focal point to be and move the camera to compose my shot. An alternate way to do this would be to select a certain focus point (not the center) and bypass the half shutter press and move the camera. (*I hope this makes sense). I used the first method last time around which works well for non-motile subjects but anything moving I had some difficulty getting the entire fish in the shot while still having the focus on the eye. Alternatively I could set the focus motor on servo which should follow the subject. Can anyone weight in their particular method? I hope I made this clear enough.
Aaron
I typical use both methods of focusing depending on the subject, composition & lens. If I have good DOF then center point works well. If DOF is limited (like with macro lens) then I'll move the focus point to the critical part of the subject like fish's eye. Since things are usually moving (either me or subject) this seems more reliable than focusing in center then having to recompose the shot. Also if the subject is not parallel to sensor plane (like angled at 45 deg) then center focus point will be on middle of fish's body & not its head, so eye will be soft focus. So when I know I want to focus off center I move the focus point to the appropriate area. Always use myD300 with AF set to continuous focus mode.
I use both as well on my D90. For wide angle I tend to use the center point and then recompose as needed (if I focus at all, often when around f5.6+, I will focus on my hand out in front of the housing and be confident that anything else will be in focus).
For Macro I tend to move the focus points to where I want my sharp focus to be. Especially when using a 105mm.
I also have my camera set up with the rear AF-ON button set to focus, so I can keep it pressed and get continuous and release to get single. The shutter button is then just for shutter, not focus. I find this to be most flexible.
Hi Aaron,
I use AI servo mode on virtually all my photography, both above and below the water, and generally speaking use the centre focus point. I always use the star button on the rear of the camera as you then free up the shutter button. You can easily let go of the star button and re-compose.
Hope this makes sense
I'm not a big fan of focus and recompose - although I do use it at times ... with caution and some basic understandings of its shortcomings ...
Here's an explanation of why it sucks and why using the other focus points might be preferable.
I use both as well on my D90. For wide angle I tend to use the center point and then recompose as needed (if I focus at all, often when around f5.6+, I will focus on my hand out in front of the housing and be confident that anything else will be in focus).
For Macro I tend to move the focus points to where I want my sharp focus to be. Especially when using a 105mm.
I also have my camera set up with the rear AF-ON button set to focus, so I can keep it pressed and get continuous and release to get single. The shutter button is then just for shutter, not focus. I find this to be most flexible.
For wide angle fast moving dolphin, sailfish, sharks I was also taught to use the AF-ON by Jim Abernethey, but I did find some pro photographers on a recent trip did not use this method and had no idea what the hell I was talking about.
What is the best focus method for hip shooting these fast moving critters?
Mike
I'm not a big fan of focus and recompose - although I do use it at times ... with caution and some basic understandings of its shortcomings ...
Here's an explanation of why it sucks and why using the other focus points might be preferable.
I agree with some of the points raised in this but if you are shooting smaller apertures it should not be a problem, although if you are shooting as in the demo in the piece above, you will obviously have DOF issues.
What is the best focus method for hip shooting these fast moving critters?
I had the best luck using AI Servo as Tim suggested for dolphins and sharks that are flying by. By biggest problem was not using a high enough shutter speed to really stop the motion.
Steve
Thanks for all the comments everyone. I took my camera out the other day to San Pedro and vis was pretty horrible so I was more or less stuck taking pictures of non-motile inverts again. I also didn't see any fish other than some drab surfperch. I didn't really try out any different focusing methods other than using AI servo which did help me compensate for the surge a bit. Unfortunately I'm now in southern Taiwan for a month without my housing to practice more. Thanks again everyone
Aaron
I agree with some of the points raised in this but if you are shooting smaller apertures it should not be a problem, although if you are shooting as in the demo in the piece above, you will obviously have DOF issues.
Unless you've entered the world of wet-diopters and then the problem is magnified. Most wet diopters I've used have a painfully narrow DOF and I never realized why some of my shots had the eye slightly out of focus until I just read what Jeremy posted.
