View Full Version : When do you use Autofocus?
Steven Taylor August 1st, 2007, 10:40 AM I'd be interested to know when people use the Autofocus feature and when it really isn't appropriate. I'm guessing its obvious when it's not appropriate as it happens..
In my short experience of the camera I've generally kept it on manual but using the push autofocus to help me out.
Bill Pryor August 1st, 2007, 10:47 AM When shooting with the DSR250 (pro version of the PD150), I used the auto focus button a lot. It was quicker than focusing the lens with the focus ring.
However, with the XH A1 I am finding the focus too slow, and it seems I have to zoom in close for critical focus whether doing it with the ring or the button. If I am on a fairly wide shot, pan to center the subject, hit the auto focus button, it may or may not land in sharp focus. So I don't use it. I'm talking about shooting 24p HDV; it may work better in other modes.
Juni Zhao August 1st, 2007, 12:17 PM I have difficulty manually focusing while zooming. So I keep pushing IAF button while zooming. But other than that I try not to use auto, coz it looks ugly when the AF is once in a while indecisive and shifts focus back and forth.
Steven Dempsey August 1st, 2007, 01:01 PM The only time I use autofocus is when I have inadvertantly enabled it. :)
Eric Weiss August 1st, 2007, 01:15 PM the push auto focus is handy, as it gets you closer to where you want to be faster. you're better off always adjusting the sharpness and depth manually.
if you leave autofocus on with a shallow depth of focus, the cam will sharpen whatever has the most movment at the time.
James Hooey August 2nd, 2007, 01:23 AM I often have to reley on the autofocus when working with my Glidecam 4000. Without a means to follow focus it is often the only way I can pull certain shots off, the camera generally plays nice but you can never trust it. When I have a controlled scene I often will set manual focus and be wide anyway with steady shots so focus is known and has a generally deep depth of field. Then it's just a matter of keeping a set distance to the subject.
Locked off on a tripod or steady shots aside....one word.....manual!
Buddy Frazer August 2nd, 2007, 06:57 AM I do a lot of single-camera stage plays where there is not an opportunity to zoom in and re-focus. I leave the camera in manual focus but push the auto-focus button every time the actors move to a different position.
I also set the focus preset to a point where the actors are most of the time. That way I can quickly get to a focus point that is pretty close.
Buddy
John Gayman August 2nd, 2007, 07:38 AM The only time I use autofocus is when I have inadvertantly enabled it. :)
I'm assuming that not many of you shoot action sports where you need to follow the player. Autofocus seems mandatory under these conditions.
Which brings up a question. Do sports broadcasters use autofocus? When I see race cars coming right at me or football and basketball plays, I'm assuming those camera guys are using autofocus. Or are they just extremely skilled at keeping the moving subject sharp using manual focus?
Eric Weiss August 2nd, 2007, 09:43 AM I'm assuming that not many of you shoot action sports where you need to follow the player. Autofocus seems mandatory under these conditions.
Which brings up a question. Do sports broadcasters use autofocus? When I see race cars coming right at me or football and basketball plays, I'm assuming those camera guys are using autofocus. Or are they just extremely skilled at keeping the moving subject sharp using manual focus?
It depends where they are in the field in relation to the shots that they will be taking. Auto Focus is a temporary creative decision, not a commitment. Further, those shots are via the magic of television. There’s typically a gaggle of operators on the floor with a producer in the control room calling out to punch the feed of the person who has the best shot at the time. Those ENG cams also have an entirely different bayonet lens system with precision auto-focus. I can take mine from 7.3mm to 102mm instantly, and with one flip I can be in macro. All that being said, it still comes down to the operator, their skillset, and whatever method they are comfortable using.
Brian Ford August 3rd, 2007, 10:35 PM Which brings up a question. Do sports broadcasters use autofocus? When I see race cars coming right at me or football and basketball plays, I'm assuming those camera guys are using autofocus. Or are they just extremely skilled at keeping the moving subject sharp using manual focus?
I do quite a bit of live sports camera work (ice hockey mostly), and it's all manual focus. The iris and black level is controlled by a guy (called the video shader) in the truck who handles anywhere up to about 8 cameras at a time.. Its not that hard to keep your focus unless you're zoomed way in and the iris is wide open. The cameras generally have a pretty wide depth of field. The monitors are always black and white CRT's and they make it quite easy to see your focus point. There is an adjustable peaking feature as well to highlight whats in focus. The focus is controlled by a remote focus handle which gets mounted onto the tripod arm so you're not using the focus ring directly. Generally I set up my camera with the focus handle on the left, and zoom handle on the right.. Most of the older guys set it up opposite (probably for historical reasons)..
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