pulseimages said:
I rented a Canon 6D with the 24-105 L lens for a shoot on Saturday from BorrowLenses.com. I went up to New England Dragway for a NHRA event and shot a ton of images but when I got home and pulled the images in photoshop they weren't tack sharp. I shot both RAW + JPEG and used just the center focus point.
I had the IS on and was shooting at good shutter speeds but the images just weren't as sharp as I thought they would be from a full frame camera. Is the 24-105 really as bad as people say it is? I noticed on on some of the images that the center would be sharp but would quickly fall off on the sides even at f11.
With results like this I wish I hadn't rented it and just brought my old Canon 40D along. At least the results would of been better. Now I'm reconsidering if I should even buy a Canon full frame all together and instead get the 70D.
There's no panning mode for the IS on that lens, you should have had it switched off. Agree with others who have asked if you adjusted AFMA.
You should post some of these shots if you haven't already.
That said, I rented the 24-105 last year with a 1D4 body, and found the lens to AF a tad slower than I liked, on it.
The 6D is fussy about its AF, also. With all points active it might grab part of the subject you don't want. With center only, mine usually works better in servo mode. The servo AF menu gives several options, and without a bit of trial and error, it's hard to say if the default settings will be better for a particular subject or event (with a particular lens)...or whether tweaking these settings would be better.
For really fast action I've found the servo tracking to work better for subjects moving toward me, rather than away. If they move away slower there is no problem, but moving away fast it can lose tracking.
Frankly, for an event like that my 70-200 f/4 (non IS) would have been far better than the 24-105. It on my 6D is the AF champ of my lenses, beating the speed of that via my favorite lens, the 135 f/2...which is no slouch.
If you used AV mode, that was also a contributing factor to your problem. You should have used TV or M modes. AV mode defaults to a shutter speed that is too slow for action shots. I would have first tried manual mode and set metering to center weighted average.
For a bright daylit event, if you used TV mode, with ISO on automatic, you could have set shutter speed to 1/800 and you probably would have wound up with the camera setting aperture from f/7.1 to f/9. The advantage of this mode over manual is you can compensate exposure. In manual mode you can't easily compensate exposure, but can specify both aperture and shutter speed. In my aerial photography I set manual mode to 1/2500 and f/9, with my 70-200...and wind up with ISO's from 800 to 2000...which works perfectly on the 6D...as the noise at these levels is still like child's play for the 6D.