20D AI SERVO question

I was shooting a volley tournament today and noticed that in AI servo my camera would not shoot 5 fps or 3fps for that matter sometimes it would take 1 pic then nothing for a second. My brother in law was next to me with my 300D and was getting more shots off. If I switch to one shot it gets right back up to 5fps. My batteries were showing half full. I am recharging them right now and hopefully that cures the problem. Has anyone else experienced this.

it is trying to re-focus between every shot. In one-shot it will only focus one time before the burst.


Regardless of what you do, this does limit you a bit,. but the bottleneck you can help is to get a faster af lens.,... I would recomemd an 85mm. Other than a lens that is that fast, get a mkII

Well that sucks!! I was using my 85mm f/1.8. I guess I just never noticed this before. Now I got to figure out how to get a MKII

The 50mm F1.8 is a pretty slow lens in terms of AF speed.

I don't know why, but this made me think of how just a few years ago I didn't even own a AF camera, nor did I want one. I just used follow focus techniques and actually had a fair amout of things in focus, when I was in practice. It's funny how things change.

I don't know what the problem is because I just tried my 20D and it happily took a bunch of images that were completely out of focus. That isn't something I normally would like as an outcome , but I wanted the shots to be out of focus to see if there was some type of interlock that would prevent shooting until focus was achieved.

On my camera I've changed the focus button with Custom Function 4. The default AF button you would push to start AF is (obviously) the shutterbutton. With Custom Function 4 and with "1" or "3" enabled, the * button on the back of the camera near your thumb starts the AF and locks it when you let go. As long as you hold in the * button it should continue to AF even when you push the shutterbutton. Anyway focus or no focus the 20D just clicked away.

I can't think of anything else that would do it. The buffer is so good with the 20D that I've never overwhelmed it even when shooting RAW at sports, and I certainly could with the 10D.

Could your camera have gone to sleep? Even then the 20D wakes up pretty quickly. How about the state of your battery? I wonder if that could do it.

If you left it by default, AI Servo with AF with shutter release button is pretty slow. You will have to continually half press it to get AF tracking. CF4-1 or CF4-2 is probably the best way to use AI Servo. You can have your thumb on the *, and just keep clicking away. Make sure you also have Continuous drive turned on.

Part of the problem is the nature of AI Servo. The default mode for AI Servo with continuous shooting is release priority for the first shot and then focus priority for subsequent shots. In One Shot, it is always release priority. So with One Shot AI Servo, your shots may be quicker, but not necessarily in focus. Setting CFN.4-1 facillitates the process by allowing you to maintain focus separate of the shutter release as already mentioned.
Scott

He used 85mm f/1.8 which is one of the fastest focusing lenses in Canpn's entire line up... certainly the fastest non "L".


Stv737,

You may want to try what ScottBerger and MBZE has recommended,. setting custom function #4 to "1" or "3"

You'll never have this problem again.

Thanks for all the replies I did the CF#4 now so I'll give that a shot.

Could it be due to your memory card write speed?

No. See my post above. The camera is trying to focus.
Scott