BIF with 7Dmk2 and Sigma 150-600C struggled big time

gqllc007 wrote in post #17743687
My biggest issue was the AI servo focus would not lock on the Heron in flight. It just hunted back and forth

That usually means it sees no contrast. I know if I just point at an open, cloudless sky the AF will do that. What focus points were you using? Was the bird against an open sky?

I was using 8 point expansion and the bird was against the background you see in these pics. I only got two pics in relative focus and the rest were unusable

Were you able to keep the bird in the viewfinder ok?

Also, if you were in one of the lens Custom modes the focus limiter is Full unless you specifically limit it for that C mode.

I haven't done much lateral BIF but have done few 45' overhead BIF. If the lens isn't pre-focused somewhere near the distance of the bird it hunts so bad you lose the bird in the viewfinder as it defocuses which only amplifies your problems.

I started pre-focusing on a distant tree or electrical tower, similar distance to the bird, and the lens started locking on much quicker. I will eventually setup one of the lens C modes with limited focus as I figure out the distances.

It was in the C mode. The 100-400 ISmk2 does a better job but it was short on reach

Rick in Ontario wrote in post #17743008
That makes me feel a whole lot better. I do OK on stationary birds at 600mm but so far have this rookie has had zero success with anything moving including a fairly large and low flying helicopter.

So far I don't know how guys do it. Maybe I need more beer?

If panning you can't be in regular OS because you'll be fighting it as you follow moving subject. Use appropriate OS.

I have a Tamron 70-300 that I use with a 7DII. Focus on birds in flight is tricky. I try to use the center spot but keeping that on a flying bird is not easy. I've tried some of the focus zones, especially in a clear sky, and that is less successful. Still the combo produces enough good results that I am encouraged.

Arthur Morris has some videos on the canon website in which he talks of how to modify unused focus cases for birds. I have followed his suggestion and it's quite good.I think this is the one you want.

Lastly, most of the problem for me is, I think, the Tamron lens. Mine is very good optically but the AF is a bit slow. I have recently had the opportunity to try out a Canon 100-400 MKII. This lens focuses like lightning. I think it is faster than my 24-105! And my results with it have been much better. So I have come to the conclusion that the lens itself plays a much bigger part in tracking a flying bird than I thought.

Hope that helps.

gqllc007 wrote in post #17743826
It was in the C mode.

So I take it that means it was set to the full range of focus?

I have a 7d and Tamron 150-600 so not the same rig, but if that's a heavy crop then it could be a tough shot. Pretty low contrast against the trees in the background which the bird seems to be fairly close to. In that case I would be in single point no expansion, ai servo, tracking sensitivity at minus 1 or 2. But that's the 7d1.

600mm is tough. I use to have the 100-400v1 and could track objects alot easier. Trying to do the same at 600mm takes alot more practice. When i was at the beach few months back trying to shoot seagulls at 600mm I was all over the place and the slightest twitch seem to throw me off target and focus would move around. I say just practice more and maybe use a smaller expansion. maybe those 8 points would get confused at 1 sec the outer points may have seen something that wanted to lock then next second you are on bird again and they want to lock that moving back and forth. I can only use surrounding on my camera but I feel 1 point around is plenty to keep on target

tonyxcom wrote in post #17743925
So I take it that means it was set to the full range of focus?

Sorry yes it was on OS1 AND Custom function1 for dynamic os and focus prioirty

gschlact wrote in post #17743903
If panning you can't be in regular OS because you'll be fighting it as you follow moving subject. Use appropriate OS.

Thanks.

I actually haven't got that far. My problem is finding the target and keeping it in the viewfinder when at 600 mm. I likely need to practice with a shorter FL and work my way up.
Problem is where I live targets of any size that are flying past are hard to come by.