Large aperture... do you AF-S or AF-C?

V8burble

V8burble

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Andrew
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When at say f/1.2-1.8 handheld and at relatively close subject distance, do you use AF-S or AF-C? Due to the very narrow DoF at such apertures do you find that even the inevitable small camera movement when handheld can shift your point of focus between focus lock and full shutter release... especially if you are in the habit of pausing at half press for the focus lock 'beep' before continuing to release the shutter. I may have just answered my own question :bang: In AF-S the shutter will not release until focus is locked, so why pause! That way, you are only talking about a delay of about 50ms in which I don't think that even I could move the camera very far.
Interested in your practices/thoughts :shrug:
 
When shooting that close, at that kind of aperture when depth of filed is tiny, I either use manual focus, or lock the focus with a first press on the shutter release. I then rock back and forth very slowly to achieve optimum focus visually on the screen, breathe out gently, and squeeze the release.

This is a popular method for macro. It also allows you to set the focus anywhere you want on the screen, not just where the focus point is.
 
I understood AF-C to be for moving subjects I am not sure I would use that for portraits unless it was an action shot.

I use a differant button when using AF on the canon that way it is locked and independant of the metering button.

Steve
 
Yes I've thought about AF-ON also... think I'll have a play.

I agree about moving objects for AF-C, although in this case it is me that is doing the small amount of movement that makes all the difference with just mm of DoF LOL.
 
If focus has to be spot on within 5-10mm then I think it's tripod time. The rocking back and forth thing isn't really accurate enough, and you'll quite likely get into camera shake too.

I use the rocking thing quite a lot for macro, but only because I'm lazy and getting the tripod out and down to an awkward angle is a hassle. And only with a static subject so that I can shoot-chimp-reshoot until it's right. I also use ring-flash so camera-shake is not a problem.

I'm not sure what you're shooting but if it's maybe a tight wide-aperture portrait, where both you and the subject are possibly moving slightly, I think there is perhaps no best way - just the one that works for you. AF-C and multi-points might work, or AF-C and single point. With portraits like this I actually use AF-S and centre point, and am constantly focusing and refocusing, but at least I know exactly what I'm getting when I press the button. With any centre point method, you have to compromise composition to make the method work, and crop the image later.

Or you could always go manual focus! It's a skill we've forgotten, and it's often not easy working through the viewfinder of a crop DSLR, with lenses that were never really designed for MF. It's a bit of an art, but I used to manage it ok ;)
 
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