p.2 #1 · Auto focus help, especially with my new Canon 500 MkII
Jim McCann wrote:
mitesh,
I use AI Servo mostly, but will in some circumstances press the DOF button to switch to One Shot. I use single point mostly, sometimes spot. On the wolf I had it set to Spot. I handheld the lens and kept shooting as the wolf moved to my left. Had the same problem with caribou walking in deep snow. I wonder if I should be pumping the back button? Perhaps there isn't enough contrast? Perplexing, but I think I'll just keep shooting, and trying different things. I sure wish I'd been able to capture the covey of ptarmigan in flight a few days ago.
It's not my area... but it's "spot" really quite small for this? I would have thought single point - or even slightly expanded if possible on a 7d - would be more effective? This would definitely help with the contrast issue.
p.2 #2 · Auto focus help, especially with my new Canon 500 MkII
PhilDrinkwater wrote:
It's not my area... but it's "spot" really quite small for this? I would have thought single point - or even slightly expanded if possible on a 7d - would be more effective? This would definitely help with the contrast issue.
Ditto to that. The smaller AF spot limits the amount of contrast for the camera to see. Try centre-point expanded.
On your lens:
1. Turn IS off, if not needed.
2. If IS is on, use Mode 1 if subject is not moving or moving slowly.
3. Turn Focus Preset to Off.
4. Male sure PF switch is set to AF.
5. Make sure Focus Limiter is set to 10m to infinity.
On your 7D:
Make sure Custom Function III-4 is set to 0 (Focus Search on).
p.2 #3 · Auto focus help, especially with my new Canon 500 MkII
Yep, I wondered about that choice to use spot AF being the culprit. Fine for face/eyes, not so fine for the body of an animal. I've yet to use point expansion. I may try that this week.
p.2 #4 · Auto focus help, especially with my new Canon 500 MkII
PetKal wrote:
+1
I looked at that (*) back button focus a few years back, and decided the thing is not for the birds .....therefore, I am still doing the main shutter release button AF.
In fact I can not fathom how can anyone who photographs action with a handheld setup use their thumb for AF.
I use my thumb for:
(1) Prehensile grip on the camera in order to help stabilise the entire setup.
(2) Aperture change on the main control dial (or EC change if I happen to be doing Av)
(3) AF point movement.
There is no "room" for anything else there.
The index finger does the central action: focussing and firing.
Thank God for this, Peter; I now don't feel like being such a rookie fool anymore for not using the back button focus. I have also tried it, but it never felt that intuitive to me, so if I am ever to use it, it will only be for AF Stop function. Besides with 61 AF points, the lock focus and recompose is pretty much a thing of the past for me.
p.2 #5 · Auto focus help, especially with my new Canon 500 MkII
Nils, as you say, we must resist things that do not feel right to us, i.e, the techniques which hinder our own photography, and it really matters not if they come from photography neophytes, or they are endorsed by old seasoned pros such as Ken Rockwell or A. Morris.
p.2 #6 · Auto focus help, especially with my new Canon 500 MkII
I am learning to use the new 500 as well. I do use the AF button for focusing. My problem so far has been images that are not sharp when near MFD. Images taken from far away are better. I have been practicing hand holding.
My 300 with a 2x converter was much slower to autofocus so I almost always had it on a tripod. I can say my images have improved as I am getting better at handholding the camera/lens.
p.2 #7 · Auto focus help, especially with my new Canon 500 MkII
Okay. So it's nice and sunny out today and I decide to get outside and do some testing with the 500. Loaded up three of my "wolves" (aka American Brittanys) into my Jeep and drove out to a secluded place on the edge of town. I selected the single point with expansion, AI Servo continuous, and when the furry miscreants came running back to me at my whistle, I let 'er rip. I got some fantastic ears a floppin mouth agape eyes a poppin' shots; nearly 100% of those I shot. Messed around for a while and started getting some way out of focus shots. Hmm, I thought something must be amiss? Checked the camera over and I see that I bumped the dial and I was now in Tv with a fstop of f32! Dear Lord I did all that just putting the behemoth lens and 7D into the case on the opposite side of the Jeep. First chance I get I'm having Canon install that lock button!
So I'm good to go again and decide to try the ol' spot AF on the dogs' fur. Results pretty much...sucked. Went back to single point with expansion and life is good once again.
I also went back to shutter button AF/Meter and I may stay there for a while. If for no other reason than it's easier to use with cold fingers, and I have cold fingers a lot here in interior Alaska.
I'm heading for the mountains again tomorrow. Hoping to photograph more ptarmigan, and if God is willing, more wolves, or maybe fox or lynx or Sasquatch.
I want to thank everyone for all of your help. I'm indebted to each of you.
p.2 #8 · Auto focus help, especially with my new Canon 500 MkII
I have had the dial change many times on my 7D and was not even aware that something had touched it. Really like the dial lock on the 5D3. Can't be bothered sending my 7D to Canon, so just check the dial every time before shooting.
Now you just need to learn to upload your photos to the N&W Forum. Some lynx shots please.
Tony
PS: About the only time I use spot focus is when shooting through branches at small birds.
p.2 #9 · Auto focus help, especially with my new Canon 500 MkII
Jim McCann wrote:
...started getting some way out of focus shots. Hmm, I thought something must be amiss? Checked the camera over and I see that I bumped the dial and I was now in Tv with a fstop of f32!
I don't know how that could cause focus errors; f/32 has extremely broad depth of field and so should in theory increase the percentage of in-focus shots.
However, to get to f/32 you'd need pretty slow shutter speeds, so motion blur and camera shake could be really bad, but that's different than out of focus.
p.2 #10 · Auto focus help, especially with my new Canon 500 MkII
Thanks, Tony! And I, too, am not wanting to be without my cameras for a long period so I won't be sending one in until this coming winter. I try to go at this like I did every time I got into the pilot's seat of an airplane and go through a check list. But in the "heat of battle," like I was a week ago when I came upon a rock ptarmigan that approached me rather closely to say mean things to me, after the shooting was over I discovered my 7D was on program! I really like the 5D Mk III for many reasons. Throughout my film life I did just fine here in Alaska with my Canon New F1s on a 500 L and probably should just own all 5D Mk IIIs instead of also having a couple of 7Ds. We'll see what happens next in the world of Canon.
I'm a happy guy again, except I sure missed some near once-in-a-lifetime opportunities at the wolf the other day. But I'm heading back up into the mountains tomorrow to where the caribou are hanging out and getting slammed by wolves, so maybe I'll get lucky again? This time I'll be ready.
p.2 #11 · Auto focus help, especially with my new Canon 500 MkII
A few people here have cast doubts on the wisdom of back button focus vs shutter button half press. It's horses for courses. some subjects demand that focus be achieved before the shot and others that focus be achieved as the shot is taken. Try focussing with the shutter button when the subject or point of focus is not under a reliable focus point, nothing worse than pressing the shutter for that once in a life time fleeting moment and watching the lens crank through it's full focus range while what ever it was fades from view.
.....therefore, I am still doing the main shutter release button AF. 
I have had the dial change many times on my 7D and was not even aware that something had touched it. Really like the dial lock on the 5D3. Can't be bothered sending my 7D to Canon, so just check the dial every time before shooting.