rscheffler
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 •Poll v3.1: MkIII have AF issues? | |
Jeff wrote:
Ron, how is your AI Servo tracking sensitivity set? I'd be curious to see if changing it to one click on the 'fast' side would change anything. I was getting a fair number of backfocused shots with the occasional front-focused shot as well, and moving one click to the fast side seems to have cleaned up that issue a bit.
rscheffler wrote:Jeff,
It's set between slow and normal. I've played around with that setting somewhat and found for the field sports I photograph regularly, setting it to the faster settings has caused problems when a player is momentarily blocked by something closer to the camera. Even at the semi-slow setting, I've found the AF tends to jump rather quickly. If I remember, I'll give your suggestion a shot at my next football game. Over at the naturescapes forum, in the huge Mark III thread, one of the guys (LesZ) recommended BIF be done at the fast setting, which makes sense since usually a BIF is the closest object to the camera. I think I will probably use the fast setting for specific situations where I know the subject will usually be the closest object to the camera.
My CF III settings are: 2-semi-slow, 6-5, 7-2 (I've made adjustments for the 400 2.8, which seemed to have helped somewhat), 8-2, 10-1 and 16: set H to 9 fps, L to 8 fps. I usually shoot at 8 fps and it "seems" to improve results somewhat, though I have not made a controlled direct comparison against 10 fps. I've used 4-1 somewhat but am not convinced it made a difference. 5-1 I've found to be too dangerous for my liking, having been burned using it a couple times.
Here's an update:
I shot an NFL preseason game - 7 pm start. Used the Mark III and a couple IIN bodies. While the light was still good I used the 600 on the III and the 400 on one of the IINs. I left the III & 600 combo set to center point AF with CF III-8-2 set because I know it works for me (and I get cross sensor sensitivity). As in the past, results were generally very good. Occasional oof images. The IIN was set to center point AF with expansion enabled and interestingly, I'd have to say the results were mixed. As it got darker, the IIN had more oof issues. Some certainly were due to my technique, but there were instances where focus should have been OK but wasn't. At the half I packed up the 600 and used the III with the 400. Based in part on the discussions going on over at the Pro Photo Home's Mark III test, the suggestion has been to set AF to "ring of fire" and let the camera select the relevant AF point. So that's what I did for much of the second half and left CF III-2 set to medium slow. Results were pretty good. Better than I expected because I generally have never trusted the ring of fire approach. It wasn't perfect, but I think on the whole better than what I was getting with the IIN & 400 during the first half. There were still sequences where AF was a bit wonky. One in particular, of a player running at me, was pretty bad with less than 50% in focus and some of the oof frames way out. During the fourth quarter I switched back to single point with expansion using one of the off center points (one up from the middle when shooting vertically) and results were also decent.
I'm still shooting at 8 fps... at least it doesn't fill the buffer as fast as 10 fps.
And it was a night game... we'll see how/if it works during a day game.
Ron
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