stupid AI servo...

Doesn't the 20D have "perdictive servo" AF mode?

Mike K wrote in post #2313317
Blonde,
I can't tell from your profile what equipment you are using, but this certainly makes a difference. I use a 1DmkII and set the CF 4-1 and 18-1 with the registered AF point to be the center one. The even in AI servo, pressing X uses just the center point only, while pressing * with my thumb activates all AF points after grabbing AF with the center one. Are you using fast glass, this helps with AI servo too.
This is the set up suggested by Sports Illustrated for sports shooting, of course the 1DmkII was made for fast paced sports.
http://www.siphoto.com​/?canon1DM2.inc
you'll notice they have some set up pages for other cameras.
Mike K

i use the exact same setup and i have it setup the exact same way

SeanH wrote in post #2313366
.....actually not a bad idea....put it where DOF preview button is......anyone actually use that anyway? It's like, let me check my DOF at f 16.........wait......I don't see a thing.......LOL

i sure don't use it...

SeanH wrote in post #2313407
Doesn't the 20D have "perdictive servo" AF mode?

yes it does and yes it sucks.

PacAce wrote in post #2312415
Nope, it's not just you. I also find myself in similar situations. But then again, it's usually when I'm also shooting birds. What Canon should do is make a camera geared specifically or bird photographer, huh?

Certainly a larger market than astrophotographers, and they got the 20Da. And this wouldn't require anywhere near as much fiddling with mechanicals. f/8 AF, one button toggle between AI-Servo and single shot AF, what else?

SkipD wrote in post #2312194
Try using Custom Function 4 set to 1. That changes the triggering for auto focus from the shutter button (half-press, of course) to the * button that's under your right thumb when you are using the camera.

You can, if you like, leave the camera on AI Servo. Then if you merely tap the * button it will autofocus and quit when your thumb is off the * button. If you hold down the * button, it will do AI Servo as long as you hold the * button down.

Personally, I don't like the AI Servo, but that's why there are so many options. I do, however, use the CF4=1 setting all the time. I really like the control it allows me. I can tell the auto focus system to do its thing when I want to and otherwise just use manual focus. For a whole series of shots at one distance from the subject I only need to focus once - not on every shot with the camera deciding different focus points for each shot because it thinks it's smarter than I am.

Hey Skip,

Thanks for this tip. I've been trying it out and I like it. There is a drastic difference when using the Sigma 17-70mm as opposed to the 50mm f/1.8. It is almost impossible with the Nifty but the Sigma is extremely fast and responsive. It's not perfect but good camera AF and good lenses seem to help this AI Servo quite a bit.

Jon wrote in post #2314827
Certainly a larger market than astrophotographers, and they got the 20Da. And this wouldn't require anywhere near as much fiddling with mechanicals. f/8 AF, one button toggle between AI-Servo and single shot AF, what else?

i think that this is about it. if i can be honest here for a second without the risk of being stoned to death, i think that if i could do it all over again, i would have gone with a Nikon D2Xs. i think that at the moment, it does offer quite a few things that i would enjoy like higher crop factor and high speed crop option. don't get me wrong, i LOVE my 1D and i do love the canon interface alot more but the D2Xs is also a great little beast.

I'd like Canon improve on the existing AI Focus algorithm on my 20D, rather than adding plus buttons.

PacAce wrote in post #2312415
Nope, it's not just you. I also find myself in similar situations. But then again, it's usually when I'm also shooting birds. What Canon should do is make a camera geared specifically or bird photographer, huh?

i wish someone would hurry up and make one that really can hit the focus on birds hope its Canon - but i would sell all my Canon gear and start again if a camera came out that did the job we want say 80% keepers reffering to spot on focus .
Rob.

gyrob wrote in post #2315461
i wish someone would hurry up and make one that really can hit the focus on birds hope its Canon - but i would sell all my Canon gear and start again if a camera came out that did the job we want say 80% keepers reffering to spot on focus .
Rob.

i am with you 100%. what i would like to do is go out and try some different bodies and see for myself which one is better. i don't have that much gear at the moment so switching should not be a big deal

Skip,

Thanks for the reminder on the CF 4=1 setting. I use that feature a lot. However, the very point you mentioned somehow eluded me at a recent air show and many of my shots were out of focus. Of course, jets in afterburner are moving a little faster that our everyday feathered friends.

This was a very humbling experience as the real problem was that I hade the AF set on ‘one shot’ (from a previous weekends event). What made it worse, in the bright sunlight I thought the pics looked OK on the LCD (don’t trust the LCD) so I never checked what focus mode I was in the entire day, dugh. Live and learn… Your reminder and my lessons will make sure I get better shots next time.

On a similar note, I did notice that the AF sometimes does not work when holding the * button and pointing the lens at different ‘targets’. I sometimes have to release the * and then press it again. This is with a 20D and 100-300. Is anybody else having this problem? It’s intermittent, which is no help when trying to figure out what the problem is.

For all, I’ve been lurking on this forum for some time and really enjoy the information and helpful information that flows so freely here. As I get smarter I hope to add my two cents. Thanks for having this forum.

Mike
One step forward, half a step back…but I’m making progress.