Posted by Terry Sohl on September 26, 2006 at 5:56 PM
Related to my other topic...I'm having focus issues with my 20d, issues that aren't "normal". When composing a shot, autofocus will often immediately shoot to infinity on my 400 5.6L, and then it gets "stuck" there until I manually turn the autofocus away from infinity. It's not the 400 5.6L, it's the camera body, as the lens works fine on my old digital Rebel.
Other than this issue though...I've still never been that thrilled with autofocus on my 20d. I guess I was expecting improvement over my old Canon 300D, but I really didn't notice much of a difference. For a non-moving target, I just about always choose the center focusing point only, use "one-shot" mode, autofocus on the critical part of what I'm shooting (birds), and then recompose before taking the shot.
Before this abnormal issue came up, this method worked fine for me on sitting birds. As for flight shots...well...let's just say I'm less than impressed on the ability of my 20D to accurately autofocus, no matter what methodology I use. For flight shots, I do take the autofocus off of "one-shot" and instead use AI focus. But no matter whether I use center-point only, use all focusing points and let the camera decide, use one-shot, use AI focus, etc...autofocus results on a moving target is always very iffy.
Are my experiences typical? Anyone else with 20D focusing issues, either the "normal" ones or my abnormal one outlined at the top?
I read something this weekend where Arthur Morris (I believe) said there was absolutely no comparison in autofocus between something like the 1DMk2 and the 20D. I've always said I'd never give in and upgrade to something like the 1DMk2, but I'm seriously considering it now. I've similarly said I'll never spend the $5,000 to get something like the 500mm IS, but that's another purchase I think I'm about ready to make.
P.S. - Don't tell my wife about anything in this last paragraph...
Posted by Bob Steele on September 26, 2006 at 10:48 PM
Terry, while I've never shot a 20D or 30D, I did shoot a 10D for several months. I do know there have been some sequential improvements in the AF performance for the 20D and 30D AF, I still seriously doubt there's much comparison with a 1D. Let look at the facts, pretty much all serious Canon shooters who demand the best AF performance and produce the most consistent results are shooting the 1D. Same with action sports photographers.
As for your specific problem with the 20D focusing on the BG and locking there - try this: once you think the focus is 'stuck' on the background, recompose to a good contrast close object, release the shutter, and press it again. If the focus doesn't move to the close object, then there's something wrong with the body.
Posted by Terry Sohl on September 26, 2006 at 11:12 PM
Thanks Bob. Yep, I've tried that. Once it gets "stuck" at infinity, it doesn't matter how often I recompose and try to refocus, it just won't budge until I manually turn the focusing ring back a bit.
Posted by Mark Wilson on September 27, 2006 at 4:23 AM
Hi Terry, I have both a 20D and 1D2N...I bought the 1D after many, many evenings trying to get images of flying Short-eared Owls last winter with the 20D - the centre focus point in AI mode could barely cope with a relatively slow flying owl (I have found the other focus points too slow for anything other than a slow moving building ). Another factor was my 400/5.6, which I have found is fine for autofocusing speed in good light with contrasty subjects, but hunts a little when things aren't ideal (such as owls in the evening). Another thing to check is the screws around the lens barrel are all tight - mine had worked a little loose recently and messed up autofocus performance (took a little while to find the cause), although it does sound like there is a problem with your 20D.
The 1D2N (as you would expect) absolutly beats the 20D on autofocus performance (speed and accuracy). It combined with the 400/5.6 was excellent with flying Atlantic Puffins this summer. That said, I still use the 20D quite a lot.
I had a similar problem a few years back... before I went digital, with Canon's 75-300 IS lens. It would work on one camera body, but not the newer ones. Sent it to Canon repair. The problem was in the lens, not the camera.
Posted by Barb Hansen on September 27, 2006 at 8:20 AM
Terry......I'm glad you brought this subject up. I have a 20 D and have very similar problems. Actually it's why I gave up on Bird photography for right now.....I thought it was my Sigma 100-300 f/4. Getting a clean image of small birds was hit and miss at best unless they were very,very close - like 12 feet or less. I have yet to get a flight shot of anything including seagulls even against a clean blue sky background. I have had focus issues with my other lenses as well especially shooting water. I have noticed one thing though, when my batteries are getting a little older or after so many rechargings the problems are much worse and more frequent. I can't afford to upgrade this camera right now, so if you contact Canon I'd be anxious to here what they have to say. I also shoot high school sports and yes I have problems there too, but I have a very narrow window that I can afford to be without my camera.
Posted by Steve Foss on September 27, 2006 at 8:33 AM
Terry, I do a lot of bird photography, and own the 20D and have access to the 1DMkIIn. There's no question the 1 is faster and more accurate on autofocus. My basic lens is the 100-400L IS, and I shoot birds in flight extensively with that and the 20D. I also shoot a fair bit of outdoor sports with the 20D/100-400 combo, and I've used Al servo for moving sports subjects with great success. Using the center focus point, I've been able to keep focus tack sharp on cross-country skiers, even as they're gliding downhill toward me at about 20 mph. I've had the same luck shooting bald eagles flying toward me. Clearly, these are in good lighting conditions. In low light, that combo will hunt for focus unless your technique is spot on. I always use Al servo on those moving subjects, never Al focus. I just don't trust Canon's claim that the camera can think fast enough in Al focus to shift to continuous focus once the subject starts to move.
All that being said, the fastest combo I've ever shot with is the MkIIn with the 400 f2.8. That is a lightning fast focusing machine! Tough to lay out nearly $10,000 on the MkIIn and 500L IS, but if you have it in the budget, you'll be thrilled with the increase in performance. Not to mention the buffer on the MkIIn and burst rate totally puts the 20D in the shade, and those are two prime considerations when shooting birds on the move. If you can get ahold of one by renting it for a weekend to try it out, you'll probably be sold. The 1 will also show you how much better your 400 f5.6 is than it seems on the 20D. You can keep that lens, add a 1.4 TC for under $300, and still get autofocus, because the 1 series will autofocus with TCs up to f8. When I strap my 100-400 on the MkIIn, it definitely moves the lens faster and more accurately than the 20D does. The 20D does offer ultraprecise autofocus on the center point, but only with lenses opening to f2.8 or wider. And, experimenting with the 400 f2.8 on the 20D, I've found that it is more precise than the 100-400.
Nothing better than upgrading to the 1 series. It's been on my mind and in my intentions, but so far hasn't fit into my budget.
Being a 20D user, this has been a very interesting thread to me. I have been very happy with my 20D vs. the digital rebel I used previously in terms of focus on stationary subjects. I've never had a problem with it locking up and it sounds like we use the camera pretty much the same way, although I leave mine on continuous rather than single shot mode. As too AI, I find it significantly better than my rebel but am still dissappointed with my low success rate when trying for flight shots. Also, I found it a real pain switching between "one shot" and AI servo when shooting a stationary subject and a niftly flying bird suddenly came by. I've at least partially solved that problem with my 500f/4 IS by using the c.f. where you can push the focus stop button on the lens to automatically switch to AI servo. I don't know the 400 5.6L but this may be something you could use too.
As to the 1DMk2N, I too have been covetting one and have been thinking I should just do it. But, although I could swing it financially I've been hesitating because the camera was introduced over a year ago. I'd feel bad if as soon as I took the dive a new version of 1D with a smaller than full size sensor and a signficant increase in MP's was announced. Of course I don't know where Canon is going with sensor size vs MP's. I've hear a few very vague comments on these forums to suggest there are some new things in the dSLR works for Canon but I have no idea what they may be. I suspect if I haven't heard about anything interesting by Christmas time I will take the plunge and keep the 20D as a backup body.
Posted by Arni Cheatham on September 29, 2006 at 4:19 PM
Hi Terry,
Couldn't get on for a few days and just saw this thread. Like Steve, I very often have a 100-400 L IS mounted on a 20D and like you, I've had very inconsistent results with flight shots (and sometimes the racking out and getting stuck business too). I was tending to blame my incononsistencies on user (read me) error. While I think I should still be plenty dilligent about improving my technique, the feedback above tends to illustrate that there are some equipment shortcomings that may be in play too. Economic realities being what they are, I'm going to send bodies, lenses, everything back to Canon around Christmastime for servicing which I'm hoping will help somewhat. (Everything's been banged on for a couple of years without serious TLC.) I hope that the Canon service approach works for you too. I'd be interested to hear either way.
Posted by Bob Steele on September 29, 2006 at 5:26 PM
Cindy Mead wrote:
"pretty much all serious Canon shooters who demand the best AF performance and produce the most consistent results are shooting the 1D.
Not true Bob. Some of us are on a fixed income and do not have the extra $$ for 'pro' equipment. Doesn't make me any less serious of a photographer, just one that has limited income to spend on equipment, due to many factors out of my control.
Cindy, I didn't say "all", and I stand by my statement.
Discussion
9 repliesOther than this issue though...I've still never been that thrilled with autofocus on my 20d. I guess I was expecting improvement over my old Canon 300D, but I really didn't notice much of a difference. For a non-moving target, I just about always choose the center focusing point only, use "one-shot" mode, autofocus on the critical part of what I'm shooting (birds), and then recompose before taking the shot.
Before this abnormal issue came up, this method worked fine for me on sitting birds. As for flight shots...well...let's just say I'm less than impressed on the ability of my 20D to accurately autofocus, no matter what methodology I use. For flight shots, I do take the autofocus off of "one-shot" and instead use AI focus. But no matter whether I use center-point only, use all focusing points and let the camera decide, use one-shot, use AI focus, etc...autofocus results on a moving target is always very iffy.
Are my experiences typical? Anyone else with 20D focusing issues, either the "normal" ones or my abnormal one outlined at the top?
I read something this weekend where Arthur Morris (I believe) said there was absolutely no comparison in autofocus between something like the 1DMk2 and the 20D. I've always said I'd never give in and upgrade to something like the 1DMk2, but I'm seriously considering it now. I've similarly said I'll never spend the $5,000 to get something like the 500mm IS, but that's another purchase I think I'm about ready to make.
P.S. - Don't tell my wife about anything in this last paragraph...
As for your specific problem with the 20D focusing on the BG and locking there - try this: once you think the focus is 'stuck' on the background, recompose to a good contrast close object, release the shutter, and press it again. If the focus doesn't move to the close object, then there's something wrong with the body.
The 1D2N (as you would expect) absolutly beats the 20D on autofocus performance (speed and accuracy). It combined with the 400/5.6 was excellent with flying Atlantic Puffins this summer. That said, I still use the 20D quite a lot.
All that being said, the fastest combo I've ever shot with is the MkIIn with the 400 f2.8. That is a lightning fast focusing machine! Tough to lay out nearly $10,000 on the MkIIn and 500L IS, but if you have it in the budget, you'll be thrilled with the increase in performance. Not to mention the buffer on the MkIIn and burst rate totally puts the 20D in the shade, and those are two prime considerations when shooting birds on the move. If you can get ahold of one by renting it for a weekend to try it out, you'll probably be sold. The 1 will also show you how much better your 400 f5.6 is than it seems on the 20D. You can keep that lens, add a 1.4 TC for under $300, and still get autofocus, because the 1 series will autofocus with TCs up to f8. When I strap my 100-400 on the MkIIn, it definitely moves the lens faster and more accurately than the 20D does. The 20D does offer ultraprecise autofocus on the center point, but only with lenses opening to f2.8 or wider. And, experimenting with the 400 f2.8 on the 20D, I've found that it is more precise than the 100-400.
Nothing better than upgrading to the 1 series. It's been on my mind and in my intentions, but so far hasn't fit into my budget.
Thank God for CPS.
Being a 20D user, this has been a very interesting thread to me. I have been very happy with my 20D vs. the digital rebel I used previously in terms of focus on stationary subjects. I've never had a problem with it locking up and it sounds like we use the camera pretty much the same way, although I leave mine on continuous rather than single shot mode. As too AI, I find it significantly better than my rebel but am still dissappointed with my low success rate when trying for flight shots. Also, I found it a real pain switching between "one shot" and AI servo when shooting a stationary subject and a niftly flying bird suddenly came by. I've at least partially solved that problem with my 500f/4 IS by using the c.f. where you can push the focus stop button on the lens to automatically switch to AI servo. I don't know the 400 5.6L but this may be something you could use too.
As to the 1DMk2N, I too have been covetting one and have been thinking I should just do it. But, although I could swing it financially I've been hesitating because the camera was introduced over a year ago. I'd feel bad if as soon as I took the dive a new version of 1D with a smaller than full size sensor and a signficant increase in MP's was announced. Of course I don't know where Canon is going with sensor size vs MP's. I've hear a few very vague comments on these forums to suggest there are some new things in the dSLR works for Canon but I have no idea what they may be. I suspect if I haven't heard about anything interesting by Christmas time I will take the plunge and keep the 20D as a backup body.
Couldn't get on for a few days and just saw this thread. Like Steve, I very often have a 100-400 L IS mounted on a 20D and like you, I've had very inconsistent results with flight shots (and sometimes the racking out and getting stuck business too). I was tending to blame my incononsistencies on user (read me) error. While I think I should still be plenty dilligent about improving my technique, the feedback above tends to illustrate that there are some equipment shortcomings that may be in play too. Economic realities being what they are, I'm going to send bodies, lenses, everything back to Canon around Christmastime for servicing which I'm hoping will help somewhat. (Everything's been banged on for a couple of years without serious TLC.) I hope that the Canon service approach works for you too. I'd be interested to hear either way.
Cindy, I didn't say "all", and I stand by my statement.