DSLRs and Auofocus


#1

Is it possible to autofocus a DSLR with lens? I’m looking at buying a DSLR for the family, but of course I’d like to try it at night too. What I envision is piggybacking the DSLR on my normal CCD imaging rig for widefield shots at the same time.


#2

Not at the moment…at least not with the focus motor on the lens. You could certainly get a robofocus and connect it up and focus that way…but that’s a little redundant. It’s doubtful that we’ll ever be able to Auto Focus a Canon camera through the focus control in the camera.

We do have some code for Canon cameras that is extremely basic. It doesn’t support AF as it’s essentially a relative focuser. I’m honestly not even sure how accurate the movements are when moving the lens…and it requires Live View (limitation of Canon’s SDK) to move the focus programatically so this may never see the light of day. If it did…it would have to go something like this:

Capture AF exposure.
Start Live View…Move Focus…End Live View
Capture AF exposure.
Start Live View…Move Focus…End Live View
Capture AF exposure.
Start Live View…Move Focus…End Live View

The entire process would not be idea. Thus the suggestion about an actual robofocus motor connected to the focus ring of the camera sounds a little less obscene.

Maybe it’s possible to run AF on Live View frames? Again, not tested and that would be an interesting test of our focus metric.

Thanks,
Jared


#3

Thanks Jared, probably not worth the effort.
joel


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