100-400L or Sig 70-200 2.8 w/extender?

My brain hurts. My fingers are sore. I've been going back and forth so many times, reading reviews, etc.

I normally rent a 100-400L for races (F1, MotoGP, etc) and am very happy with the results. Looking to purchase a lens, and initially I figured I would just buy a 100-400L.

Then I started talking to a co-worker who has a Sigma 70-200 f2.8. That got me thinking that the Sigma would be much more versatile than the Canon if I add an extender.

My concern is that the AF won't be as accurate with the extender. Am I worried for nothing? Any suggestions about this setup would be greatly appreciated.

I am interested in this as well. Looking forward to seeing answers from those with experience.

i was toying with a similar decision recently. 100-400L or 70-200L 2.8

I ended up going with the 100-400 and i'll now be carrying 2 bodies (the other running a 28-105)

urbanfreestyle wrote in post #16659779
i was toying with a similar decision recently. 100-400L or 70-200L 2.8

I ended up going with the 100-400 and i'll now be carrying 2 bodies (the other running a 28-105)

When I would rent the 100-400 I pretty much kept it on all day. The only time I ever changed is when we were around the pits/paddock.

All of my problems would go away if the 100-400 was a 2.8 and still cost $1500

haha yeah. i do like having F2.8 but realisticaly i found i never stopped down that far. I have got plents of DOF at the higher minimum Fstops. but each to their own

urbanfreestyle wrote in post #16659995
haha yeah. i do like having F2.8 but realisticaly i found i never stopped down that far. I have got plents of DOF at the higher minimum Fstops. but each to their own

For most of the time I agree, esp for motorsport. Just thinking about other times when having the extra DOF would come in handy.

???

330cic wrote in post #16660160
For most of the time I agree, esp for motorsport. Just thinking about other times when having the extra DOF would come in handy.

???

Extra DOF? You mean shallower DOF. Extra DOF would be at F22. As for the original question. If you shoot beyond 200 very often get the 100-400 as extenders are always a compromise. You lose IQ, an Aperture or two, and focus speed.

gonzogolf wrote in post #16660177
Extra DOF? You mean shallower DOF. Extra DOF would be at F22. As for the original question. If you shoot beyond 200 very often get the 100-400 as extenders are always a compromise. You lose IQ, an Aperture or two, and focus speed.

Sound advice above. I'll add that if you're shooting during the day, 2.8 won't be of any great benefit. If you were shooting at night then it would clearly be of help. As for extenders, the above comments are also spot on.

If all you shoot is motorsports then the 100-400 might be best, but a 70-200 is a much more versatile lens for the rest of the time. I'd say that when I use my 70-200 probably at least 75% of my photos are wider than f4.

gonzogolf wrote in post #16660177
...As for the original question. If you shoot beyond 200 very often get the 100-400 as extenders are always a compromise. You lose IQ, an Aperture or two, and focus speed.

Yes. Folks manage to get by with the extender and a 70-200, but your best chance of success comes with buying the thing that gets you the focal length you need, natively, vs adapting something that wasn't built to go that far with another set of glass.

Plus, switching out and tracking other pieces of gear in the field is a PITA, for me at least...especially smaller pieces.

Problem solved. I got the Sigma 70-200 f2.8 and gonna wait a bit and get the Sigma 150-500. No extender needed, I get up to 500mm for the extra $500.