7D inconsistent AF in AI servo

[Trevor Allen]

with centre point only, focusing with the back button. I used this method for years at events, but on Sunday the keeper rate was the worst I've ever had from any camera, which includes 10D 20d DS2 40D 5D 5D2 & Nikon D700, anyone experience same.

The camera in some cases locks on with the first frame in focus, but then loses it, also some of the static shots are way out

Anyway to improve consistent AF shots, or is it just the way the 7D is?

 

[Paul G5]

I only had my camera a week, but I had no problems when trying out AI servo at my son's hockey practice on Saturday. I tried both AF expanded and single center point and both yeilded very good results. The rink isn't exactly the best lighting either so I was really impressed with the results. Hopefully, your camera doesn' t have a problem.

 

[Tom Weigand]

I just used my 7D for the first time at a sporting event last weekend. After reading the book, and some articles on the new AF and exposure system, I saw where the 19 point auto selection AF mode is significantly different than the previous 9 point auto selection. I would never use the previous system, as it would just pick the "closest" subject, which isn't what you really want most of the time. If it was supposed to work with AI Servo, I never tried it. With the 7D, I read where using 19 point auto selection AF, you could first pick a "primary" AF point (center point for me), and when combined with AI Servo mode, the camera would lock on the center point first, then attempt to track that subject with any of the other 18 points if the subject moved off center. Plus it would show those points in the viewfinder. I was skeptical, but gave it a try and it worked very well for me. I was shooting with a Canon 70-200mm f/2.8 (non-IS) lens at a football game and was getting a much better "keeper" rate than with my 40D or 50D.

 

[DemiLion]

with centre point only, focusing with the back button. I used this method for years at events, but on Sunday the keeper rate was the worst I've ever had from any camera, which includes 10D 20d DS2 40D 5D 5D2 & Nikon D700, anyone experience same.

The camera in some cases locks on with the first frame in focus, but then loses it, also some of the static shots are way out

Anyway to improve consistent AF shots, or is it just the way the 7D is?

Read through this guide to AF CFn settings:

http://www.canonrumors.com/files/1dm4cfnguide.pdf

Yes it's for the 1DMkIV, but most of the settings are very similar/identical, and you can filter out (mentally) what you don't need.

Ignore the last part, as it refers to the MkIV ISO which is irrelevant to the 7D.

 

[Clicker]

C.Fn III: Autofocus/Drive
C.Fn III -1 AI Servo tracking sensitivity

During focusing in AI Servo AF mode, the AF sensitivity for tracking
subjects (or obstacles) moving into AF points can be set to one of five
levels.

If it is set toward [Slow], interruptions by any obstacles will be less
disruptive. It makes it easier to keep tracking the target subject.
If it is set toward [Fast], it will be easier to focus any subjects which
suddenly enter the picture from the side. Convenient when you want to
successively photograph multiple subjects located at random distances.

--
Clicker

 

[Karl Gnter Wnsch]

with centre point only,

Why make life so hard for yourself?
--
regards
Karl Günter Wünsch

 

[Trevor Allen]

& your solution?

 

[Brit]

and what were your other AF related settings?

with centre point only, focusing with the back button. I used this method for years at events, but on Sunday the keeper rate was the worst I've ever had from any camera, which includes 10D 20d DS2 40D 5D 5D2 & Nikon D700, anyone experience same.

The camera in some cases locks on with the first frame in focus, but then loses it, also some of the static shots are way out

Anyway to improve consistent AF shots, or is it just the way the 7D is?

 

[Trevor Allen]

TV 1/320 & 1/500 f4IS (off) L lens @ ISO 3200 + 1/3 or 2/3 stop increase in light, for indoor showing equestrian, which includes, cantor, running, & static shots, which is something I do all the time, not usually any problem, the first time I have used the 7D for this, also I used a D700 with f1.8 lens for when light dropped, which was fine. I usually use the D700 with a 70 to 200 f2.8, when indoors, but was trying to use lighter gear, as recently had a OP.

 

[elfroggio]

I'm very happy with the AI Servo tracking on the 7D.

1. What setting are you using?
2. What about: C.Fn III -2 AI Servo 1st/2nd Image Priority. It tells the 7d who has priority, the AF, the drive... My explanation is at: http://www.foto-biz.com/Canon/Cfn-iii-2-ai-servo-1st-2nd-image-priority

--
Thanks
http://foto-biz.com
The Business of Being a Photographer -- Lightroom Q&A

 

[carlk]

It's just the way the 7D is. No of course not. You sounded like an experienced user. You should have no problem figure it out. Send the camera to Canon service if you still can't get it to work.

BTW I use AI servo and back button to shoot events too. I use single AF point but not restricted to the center point (can't figure out why you would only use the center point). Not problem with AF at all.

with centre point only, focusing with the back button. I used this method for years at events, but on Sunday the keeper rate was the worst I've ever had from any camera, which includes 10D 20d DS2 40D 5D 5D2 & Nikon D700, anyone experience same.

The camera in some cases locks on with the first frame in focus, but then loses it, also some of the static shots are way out

Anyway to improve consistent AF shots, or is it just the way the 7D is?

 

[kikiriki]

Slow down AF tracking.. I found 7D's AF system too fast for most of the regular shooting. Same is with 1D IV. Sometimes i use slow speed even for bird shooting.. Fast and even middle is only for objects moving very fast from or towards you..

BR
--
Igor Leskovar

 

[wimpy007]

Mine is back to Canon to repair 'inconsistent focus'.

Don't let people (some) here make you believe it's you, there are indeed some 7D's with an inconsistent focus, ai servo and one shot ... No matter what you try, in the end you'll have to hand it to Canon repair to solve the problem.

 

[samWebster123]

cause my 7D AI servo is dead on shooting fast moving owls flying toward me which is the most demanding ai servo shooting I've experienced.

I have a 1d4, 7d, 1dm2n and I have yet to experience a situation shooting BIF, wildlife or sports where the 7D hasn't kept up to the 1d4.

 

[Dave Jr]

So, with a fast dog running right at you, you should speed up the AF tracking, moving the setting to the right of the center position?

Slow down AF tracking.. I found 7D's AF system too fast for most of the regular shooting. Same is with 1D IV. Sometimes i use slow speed even for bird shooting.. Fast and even middle is only for objects moving very fast from or towards you..

BR
--
Igor Leskovar

 

[DemiLion]

cause my 7D AI servo is dead on shooting fast moving owls flying toward me which is the most demanding ai servo shooting I've experienced.

I have a 1d4, 7d, 1dm2n and I have yet to experience a situation shooting BIF, wildlife or sports where the 7D hasn't kept up to the 1d4.

Whilst not denying that head on focus can be hard, I'd say that there are certainly situations that are more challenging. Two examples:

Basketball at the hoop where you are trying to maintain focus on one single player.

Football(soccer)/Rugby where again the focus is on one player.

In both these circumstances you have mutliple players in a confined area, with multiple crossing targets. Keeping focused locked on one player in that situation is very very challenging.

 

[carlk]

Object going fast toward you is the toughest test on the AF system. The other situations you described are more dependent on the operator skill: how you set up the AF system and how you operate the camera. You still need a good AF system with options you can choose from that will do the job though.

cause my 7D AI servo is dead on shooting fast moving owls flying toward me which is the most demanding ai servo shooting I've experienced.

I have a 1d4, 7d, 1dm2n and I have yet to experience a situation shooting BIF, wildlife or sports where the 7D hasn't kept up to the 1d4.

Whilst not denying that head on focus can be hard, I'd say that there are certainly situations that are more challenging. Two examples:

Basketball at the hoop where you are trying to maintain focus on one single player.

Football(soccer)/Rugby where again the focus is on one player.

In both these circumstances you have mutliple players in a confined area, with multiple crossing targets. Keeping focused locked on one player in that situation is very very challenging.

 

[samWebster123]

Don't deny sports is challenging but nothing compares to tracking a large owl coming out of the trees directly to within 6 feet your position in a matter of a few seconds. Lots of background distraction and potential objects moving in front of the target. Not only does it demand perfect technique from the camera operator but puts huge demands on the Af system.

Object going fast toward you is the toughest test on the AF system. The other situations you described are more dependent on the operator skill: how you set up the AF system and how you operate the camera. You still need a good AF system with options you can choose from that will do the job though.

cause my 7D AI servo is dead on shooting fast moving owls flying toward me which is the most demanding ai servo shooting I've experienced.

I have a 1d4, 7d, 1dm2n and I have yet to experience a situation shooting BIF, wildlife or sports where the 7D hasn't kept up to the 1d4.

Whilst not denying that head on focus can be hard, I'd say that there are certainly situations that are more challenging. Two examples:

Basketball at the hoop where you are trying to maintain focus on one single player.

Football(soccer)/Rugby where again the focus is on one player.

In both these circumstances you have mutliple players in a confined area, with multiple crossing targets. Keeping focused locked on one player in that situation is very very challenging.

 

[DemiLion]

I completely agree that head on is a great challenge to the AF system. At roughly 40 mph the owl is traveling at approximately the same speed as a thoroughbred on a 5 furlong sprint, albeit that the horse is a far larger target. I do think that close action sport presents different challenges though!

That aside I think that we are probably debating a moot point, and the fact is that the 7D AF system is damn good. I had a 95% keeper rate on my last shoot (equestrain stuff) which is a huge improvement on the 30D.

I would hesitate to assume that the camera needs repair though, just because ours seem to be working OK. The OP has already returned one for fixing and has had a number of other issues. I'm not casting aspersions at him, just pointing out that the AF sys is complex, and needs some time to get to grips with. I know that I needed to practice on BIF before the Eventing season started to get the settings right and know which functions I needed to adjust. Suggesting a return to Canon after just one session might be jumping the gun a bit.

Don't deny sports is challenging but nothing compares to tracking a large owl coming out of the trees directly to within 6 feet your position in a matter of a few seconds. Lots of background distraction and potential objects moving in front of the target. Not only does it demand perfect technique from the camera operator but puts huge demands on the Af system.

Object going fast toward you is the toughest test on the AF system. The other situations you described are more dependent on the operator skill: how you set up the AF system and how you operate the camera. You still need a good AF system with options you can choose from that will do the job though.

cause my 7D AI servo is dead on shooting fast moving owls flying toward me which is the most demanding ai servo shooting I've experienced.

I have a 1d4, 7d, 1dm2n and I have yet to experience a situation shooting BIF, wildlife or sports where the 7D hasn't kept up to the 1d4.

Whilst not denying that head on focus can be hard, I'd say that there are certainly situations that are more challenging. Two examples:

Basketball at the hoop where you are trying to maintain focus on one single player.

Football(soccer)/Rugby where again the focus is on one player.

In both these circumstances you have mutliple players in a confined area, with multiple crossing targets. Keeping focused locked on one player in that situation is very very challenging.

 

[MoultonP]

Dave Jr

The answer to your question is no - C.Fn III-1: tracking sensitivity has nothing to do with the speed of the subject being tracked - it is the speed at which the camera will try to find focus if the subject moves away from the active point.

Lets assume you are using a single focus point and you are tracking your dogs nose as he runs toward you. All of a sudden the dog jinks to one side and you have to move to get the active focus point back on his nose.

If you have the tracking sensitivity set to fast, the camera might already be trying to find the new focus behind where the dog was before you get the point back over his nose. That would mean it then has to search again to re-acquire (most likely you will have to release and press the button again to force it)

If you had C.Fn III-1: tracking sensitivity set to slow, you should be able to get the active point back over the nose before focus has moved and the camera will therefore keep tracking correctly.