Upload & Sell: On
I did a search on this but I didn't see anything super relevant. I currently wildlife shoot with a 7D + 500 f4. I am usually focal length limited and often shoot with the 1.4x on the lens. When the new 600 II was announced, I thought it was a great idea to upgrade to the MKIV and the 600 II. I would have (almost) the same reach for (almost) the same weight. Plus my wallet would be a lot lighter so that would lessen the load as well. The camera would be a upgrade from the 7D so life would be good.
After thinking about this a bit more, I'm not so sure so I was hoping those that have shot with both cameras could chime in. The primary reasons I thought the change would be good is due to better AF and IQ. The 7D is at least a stop noisier than the IV and the IV has, generally, a better AF system. I used to shoot with a 1D MKII. As a AF comparison, it was easier for me to get hand held sharp pictures, but I think that's a matter of the pixel density rather than the AF. When shooting on a tripod, the AF system seems to be pretty darn good. The only time the 7D AF has really let me down is when, for example, I have something like a Northern Harrier flying against a brown grassy field. The 7D would not lock on the bird, although that could have been me as well or the camera settings.
Ok so back to my issue. Let's say I have the 600 II. On a 7D, that would give me 600*1.6 = 960mm eq. length with 18 mpx. On the IV, I'd have 600*1.3 = 780 eq. length with 16 mpx. For me to have the same reach on the IV, I would need (960/780)*(18/16)^.5 = 1.3x more reach. Thus, I would essentially need to attach a 1.4x to get the same reach with the IV. That means:
- I'm shooting at 5.6 rather than 4
- Ergo, I am shooting at 1 stop higher ISO to get the same shutter speed
- I get an IQ hit due to the extender on the lens
- I get 50% reduced AF performance
So, the bottom line is I'm not sure that I'd get much of an upgrade in AF or IQ. Of course, the IV does have better weather sealing, and gives 10 fps rather than 8.
Anyway, I'm curious on anyone's experience.