I thought it would be helpful to have one post that summarizes 5DMk3 focusing when using extenders. I am picking up one of these soon and will add my experiences. I never had much luck with my 7D, but let's see how it's working for others.
So far, reports have the following combinations work well:
You might want to include:
- lens / extender / AF mode / AF speed: good, fair, bad / AF accuracy: good, fair, bad
- include notes on subject, lighting and keeper rate.
Example:
Canon 70-200f4 IS
Kenko Pro 300 DGX 2x TC
AF modes: all modes work
AF speed: fair
AF accuracy: good
Notes: hand-held on stationery subjects with in low light, overexposes about 1/3 stop
using 400 5.6L with non-reporting TC's for 560mm F8
Update 10/22/2012
Tamron SP AF 1.4x Pro Teleconverter for Canon Mount Lenses
This is the best 1.4X TC I have tested for the 5D III to focus at F8. I am getting images with excellent sharpness in the center, and very good sharpness accross the frame. The 5D III focus with the 400mm F5.6 is quick with single point focus, and IS Servo or single point focus.
I have no issue focusing birds or birds in flight with the Tamron SP AF 1.4x Pro TC.
Schlotkins wrote:
I thought it would be helpful to have one post that summarizes 5DMk3 focusing when using extenders. I am picking up one of these soon and will add my experiences. I never had much luck with my 7D, but let's see how it's working for others.
So far, reports have the following combinations work well:
I'll try out my 5D III + 100-400L + Kenko 1.4 and 5D III + 500 + 1.4x III + Kenko 1.4x and see how it goes.
This is why I always have 7D with me when birding, since 7D + Any Lens still puts more pixels on the duck than 5D III + Any Lens + 1.4. It's the best TC out there and is effectively 1.5x compared to 5D III.
Pixel Perfect wrote:
I'll try out my 5D III + 100-400L + Kenko 1.4 and 5D III + 500 + 1.4x III + Kenko 1.4x and see how it goes.
This is why I always have 7D with me when birding, since 7D + Any Lens still puts more pixels on the duck than 5D III + Any Lens + 1.4. It's the best TC out there and is effectively 1.5x compared to 5D III.
Yea, I think that's generally true. With that said, I am kind of curious if one would be better off using the 5D + 1.4x + 500L II instead of the 7D + 500L II. Sure, you have to give up one ISO and about 1 mpx, but according to Dxomark, the 5d MKIII is close to 2 stops better in the noise department. I'm fairly sure stacked 1.4x's on the 5D would be inferior to the 7D + 1.4x + 500.
Schlotkins wrote:
Yea, I think that's generally true. With that said, I am kind of curious if one would be better off using the 5D + 1.4x + 500L II instead of the 7D + 500L II. Sure, you have to give up one ISO and about 1 mpx, but according to Dxomark, the 5d MKIII is close to 2 stops better in the noise department. I'm fairly sure stacked 1.4x's on the 5D would be inferior to the 7D + 1.4x + 500.
Chris
Also Chris what about AF speed? Will 5D III's superior AF be enough to compensate for slow down of AF when you attach a 1.4x TC? I'd still think the 7D + bare lens will be a bit better, but would need to verify this.
I agree if you need a 2x on an f/4 lens, the 7D + 1.4x + lens combo should be much better for AF than the 5D III
BTW for those wondering what the pixel advantage is of a 7D + lens vs 5D III + lens + 1.4x it's simple. Adding a 1.4x is the same as using a sensor that had 2x the number of pixels, so a 5D III + 1.4x would give me the same reach as a 44MP FF. If we crop this to 7D FOV we would get 44/1.6^2 = 17.2MP. So about a wash.
If high speed AI servo is necessary there is an option of the 5DII and 5DIII bodies. Live View "live" will work without pin tape or any such tricks. This is contrast detection AF and is of course much slower than phase detect AF, but it is accurate, usually more accurate than phase detect AF and has no lens calibration issues. Tty it with your 400 f5.6 lens and 1.4X TC. It works!
