Alistair Watson wrote:
First off, forget +2 on the AI Servo tracking sensitivity. This is the frequency that the AF emits to gain focus lock. I have had good results in 0 and sometimes +1 but as you say, +2 just makes the focussing totally hyper and the results speak for themselves.
I don't understand that, I thought it controlled how quickly the AF jumps between subjects. If you have a moment, could you elaborate?
Alistair Watson wrote:
Do you still have the 30D? If so, I would use that for your paid gig.
The problem I have isn't in daylight and this is a cd single cover shot in the afternoon. I shot yesterday with a 300/2.8 from noon to 3pm and my Mk III was great in Servo. It's just the primes in club lights that's the problem. I'd be kicking myself using the 30D when the IQ is noticeably better on the Mk III.
Alistair Watson wrote:
My experiences with the 1D3 in very low light are outstanding, it is in normal sunlight conditions that I have my problem. To that end, after a long conversation with Canon CPS today I am going to send all my gear into Canon next Monday to get it calibrated and body matched. I tend to do this once every 1 1/2 years since my gear has a hard time, cleaning, service and calibration I find ensures each lens is spot on. Perhaps you might find this worthwhile.
I've thought about sending them my Mk III and my primes, but I'm not a CPS member and need to better Servo functions that my 30D can do (more polo) for some gigs in early October. I'm worried that the turnaround is going to mess me up. Ironically, this issue with the primes hurts me as much as the Servo issue does for the hardcore sports shooter. Maybe I can find someone to trade with depending on the job
By the way, thanks for your time and concern. I really appreciate it.
I am surprised at this problem. If this contines, you might be inclined to have it serviced by Canon. I normally shoot centre spot only - I will give other spots a try to see what happens.
I shoot a lot of very low light events (dance, theatre, jazz, etc) and find that the focus is better than any other camera I have used - for example:
If you do not like the idea of carrying a flash unit just for the assist beam, try an ST-E2. It is light and doesn't get in the way and would help the 30D as well as the MKIII. It only works in One Shot AF though.
As others have posted, I do not have a problem with my MKIII in low light. I believe you may have a bigger problem than the RG syndrome.
Valerie S wrote:
I don't understand that, I thought it controlled how quickly the AF jumps between subjects. If you have a moment, could you elaborate?
I had a long conversation with Canon UK this morning about this very topic.
AI Servo tracking sensitivity controls how often the camera will focus on a subject, ie how often the camera will acquire the camera to subject range data. It also controls how quickly the camera will re-focus on a subject when AF lock is lost. I understand it works very very closely with CFn III 4. If you have CFn III 4 set to 0 (default) then any subject coming between your camera and your subject will cause the camera to instantly (speed determined by AI tracking sensitivity) refocus on this nearer subject. Setting CFn III 4 to 1 maintains the existing subject range data and also uses the predictive algorithms to determine range so any person walking between you and your subject won't cause the AF to jump on the closer target.
This CFn existed on the 1D2N as well but I never felt the need to change it. Canon UK said that few photographers are capable of using the camera set to +2. They gave the example of setting at +2 during a Formula 1 race, and that you were skilled enough to maintain the centre AF point on the driver's helmet at all times then focus lock would never be lost. As crazy as this sounds it kind of makes sense, or maybe my brain is screwed from reading every single technical document to hand on the Mark 3 AF and taking thousands of shots experimenting with each CFn! Either way, I certainly don't know of any sports photographer who uses it successfully, either on the Mark 3 or the Mark 2. I shot at length using +2 at a rugby match and the focus motors worked overtime, I could feel the lens continually hunting, not much but enough to feel the optics moving back and forth slightly, totally hyper and the results were rubbish.
Setting it to 0 or +1 should be fine for what you are doing.
Valerie S wrote:
The problem I have isn't in daylight and this is a cd single cover shot in the afternoon. I shot yesterday with a 300/2.8 from noon to 3pm and my Mk III was great in Servo. It's just the primes in club lights that's the problem. I'd be kicking myself using the 30D when the IQ is noticeably better on the Mk III.
First off, for a CD single cover I don't think anyone would notice the difference between a 1D3 shot and a 30D shot due to the image size. Perhaps I am wrong, I have no experience in this area. but the smaller the print, the less visible the flaws become though it sounds like we both share the same perfectionist traits!
Should I assume that the 300/2.8 works perfectly well wide open in daylight? Are you able to get sharp focussed shots right on the focus point with your other primes in daylight? If so, then this isn't likely to be a calibration issue. If you can't get a sharp shot on your primes in daylight then I would absolutely say send it all in for body/lens matching.
Valerie S wrote:
I've thought about sending them my Mk III and my primes, but I'm not a CPS member and need to better Servo functions that my 30D can do (more polo) for some gigs in early October. I'm worried that the turnaround is going to mess me up. Ironically, this issue with the primes hurts me as much as the Servo issue does for the hardcore sports shooter. Maybe I can find someone to trade with depending on the job
Even if you are not CPS, I would still choose 1 lens and your Mark 3 body and send it in. That way, you can still shoot with your 30D and other lenses. If the Mark 3/lens come back sharp as a nut then you found your problem. Either way, I have become so desperate with my 1D3 this seems like the only viable alternative left to me. Turnaround shouldn't be anymore than a week but I would call your nearest Canon service centre to find out more. It should be free as well since the body is within warranty.
I would rather have an in focus sharp 30D shot with a little more noise (not so visible at the size of your output anyway) than a higher IQ unfocussed shot from a Mark 3 so don't be so hard on your little 30D. Trust me, I have the same opinion of my Mark 2N, it delivers the shots I need, sure it has a little more noise but the results speak for themselves. My 1D3 is now in retirement until it gets calibrated.
Edited by Alistair Watson on Sep 17, 2007 at 08:59 PM GMT
The more I hear about these issues the more I suspect the problems surrounding the MKIII's focusing revolves around an overdependence on particular wavelengths of light.
With respect, I believe you and your CPS friend may be mistaken. If I follow what you are saying, AF sensitivity set to slow, the camera checks the camera to subject distance less frequently, then a subject moving towards me a high rate of speed would never be tracked correctly, only subjects at slow speeds could be tracked. I would have to set the camera to fast to follow a race car and as you know that is not the case. Canon's paper on the MKIII and other ID series cameras clearly state " the tracking caluculation speed is unchanged based on tracking sensitivity. Tracking sensitivity determines how fast the camera will switch targets."
As far as the CF III-4 set to 1 the camera will continue to track the original subject only if an assist point has picked it up. If the subject that crosses in front of you is so large that it blocks the main and assist points, focus will be lost.
I didn't say that above 0 the camera would track a moving object any faster. This is clearly written in the Custom Functions III : Autofocus/Drive 1D3 White Paper. You are right though, I could have explained it more clearly.
Lets put it another way.
Say you are tracking a racecar and for whatever reason AF lock is lost. With AI Servo sensitivity set at 0 it takes, for example, 0.5 seconds for the AF to realise lock is lost and trigger a re-focus. Set at +2 when AF lock is lost, an re-focus is requested in 0.1 seconds. Set at 0 the AF tracks the car smoothly, no lens hunting and lock is maintained, set at +2 the lens hunts continually, minute movements, no smooth AF tracking movement as on the 0 setting and there is nothing between me and the target for the focus to jump onto, just the racecar, the same target.
I don't know how else to explain it than it feels like the camera is continually calculating range data to the subject, I really don't know how else to say it. At +2 my results are rubbish anyway so that is all there is to it.
Now I have confused myself silly so I am off to the pub, I really need a big drink!
Bottom line; If the OP is having trouble getting her MkIII to focus as well as a 30D in low light, worrying with AI Servo CF's is not the answer. I believe she has bigger problems with the camera.
Has anyone heard if the latest firmware update had a significant impact on the MIII focusing issue? The last I heard was that is was being installed on select cameras at some sporting even in Asia. What was the outcome?
Edited by Jeff on Sep 20, 2007 at 06:38 PM GMT (Reason: Title for clarity)
I was speaking to CPS the other day, all they keep telling me is they are working with the pro photographers and developing a new firmware. Last I heard was that it wouldn't be available durinng September.
When was that? Just last week they were installing 1.1.1 in some cameras at the IAAF World Championships. Canon set up a special temporary service center just for that purpose.
Edited by nathanlake on Sep 19, 2007 at 08:51 AM GMT
A few days ago. Apparently they have been beta testing many of the pro bodies at the Osaka event but what version will eventually be released to us and when is open to guesses it seems.
Alistair Watson wrote:
A few days ago. Apparently they have been beta testing many of the pro bodies at the Osaka event but what version will eventually be released to us and when is open to guesses it seems.
At this point, I don't really care when it is released. I want to know how well it worked.
Well I have 1.1.1 and it has improved AF... I did not have the problems others had. However in AIServo focusing on a still subject it no longer hunts but stays solid.....
The CPS rep did say it addresses the AF issues (his words)
Peter Woods wrote:
I did not have the problems others had. However in AIServo focusing on a still subject it no longer hunts but stays solid.....
quote]
Mine has never hunted in AI servo when focusing on a still subject.
Mine does, You can watch it go in and out of focus slightly, I think one of the bigger problems I see in my camera is when I am tracking lets say a duck in the sky, Very easy subject to lock onto, When the duck moves lower where the background suddenly has trees in the far distance the camera will almost always head over to the trees even though I had been following the duck for some time. I have tried all sorts of CF changes and nothing has helped. I used center point, center point expanded and all 45 points. The camera wants to head into the trees almost every time.
Mine has never hunted in AI servo when focusing on a still subject.
Mine jiggles back and forth constantly when still and pointed at a still object. It is always close to focus, but it regularly goes from sharp focus to less sharp. 1.1.1 sounds like great news.
