Extenders
- Canon Extender EF 1.4x III
- Kenko Teleplus Pro 300 DG 1.4x AF-C
- Canon Extender EF 2x III
Lenses
- Canon EF 70-200/4 L USM
- Canon EF 70-200/2.8 L IS II USM
- Canon EF 100-400/4.5-5.6L IS
- Canon EF 500/4 L IS USM
Procedure - all handheld shooting, Canon EOS 1DX, firmware v. 1.0.6, One-Shot AF, ISO 800, all tests with lenses wide open, at f/8, start by manual defocusing lens, then attempt to AF on a fairly bright lamp with high contrast details on the lamp shade, at approx 12m distance. The first two example photos show (i) the hallway and (ii) the target lamp. Tests were performed inside today. It was a very overcast day, as there is heavy rain from the remnants of Hurricane Isaac here today. The third example photo shows taped contacts on the 100-400L lens.
Note that the Kenko 'DG' teleconverter I used was purchased in 2009. The contemporary version is 'DGX'. I don't know if they are the same or different in some way. Edit: a recent link posted by Yakim on the 800mm f/5.6 + 1D-X + 1.4x Extender = Apparently It Can AF!
thread describes differences between the DG and DGX teleconverters, https://www.fredmiranda.com/forum/topic/1144996/4#10939274
Results
70-200/4L + 2x III
- contacts not taped
no AF
1DX reports f/8
- contacts taped
AF smooth but 'hunts' continuously, poor accuracy
1DX reports f/4
70-200/4L + 1.4x III + 1.4x DG
- contacts not taped
AF smooth and accurate
focus confirmation 'finder flash' active
1DX reports f/5.6
- contacts taped
AF jerky & discontinuous, poor accuracy
1DX reports f/4
70-200/2.8L IS II + 2x III + 1.4x DG
(only possible combination for f/8)
- contacts not taped
AF smooth and accurate
focus confirmation 'finder flash' active
1DX reports f/5.6
- contacts taped
AF smooth but 'hunts' continuously, poor accuracy
1DX reports f/2.8
100-400L + 1.4x III
- contacts not taped
no AF at any focal length
1DX reports f/6.3 at 100mm to f/8 at 400mm
- contacts taped
AF smooth but 'hunts', poor accuracy but sometimes locks on OK
1DX reports f/4.5 at 100mm to f/5.6 at 400mm
100-400L + 1.4x DG
- contacts not taped
no AF at any focal length
1DX reports f/6.3 at 100mm to f/8 at 400mm
- contacts taped
AF smooth and accurate
focus confirmation 'finder flash' active
1DX reports f/4.5 at 100mm to f/5.6 at 400mm
500/4L + 2x III
- contacts not taped
no AF
1DX reports f/8
- contacts taped
AF jerky & discontinuous, no focus lock achieved
1DX reports f/4
500/4L IS + 1.4x III + 1.4x DG,
- contacts not taped
AF smooth, often accurate
focus confirmation 'finder flash' not active
1DX reports f/5.6
- contacts taped
AF jittery, often accurate lock but moves off if AF-ON button held down
focus confirmation 'finder flash' not active
1DX reports f/4
Comment: if I want consistent AF performance at f/8, I'll use my 1D Mark IV.
Edit: new info on Kenko DG vs. DGX teleconverters added to para. 2.
Jim, thanks for the test. The last picture you depicted, that of your 100-400mm lens, so, did you tape the lens end before you mount the TC on? Not that it matters, I guess, but I taped the TC end where I mounted the lens on.
When I did a more limited testing on my 5D Mark III back then, I noticed that the AF performance was significantly better outdoor in good light then indoor although I turned the light on, too, but I didn't use any lamp to actually focus on though. Based on the images, I assume you did the testing indoor and in the evening?
Joshua
Sep 05, 2012 at 04:25 PM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
Your 500f/4 with the 2XIII behaves exactly as my 400 DO does with the 2XIII. Hopefully Canon will release a firmware update to address this as it seems like the camera is quite capable of focusing at f/8 in somce of your other tests.
Great work Jim and as expected. I agree use 1D II/III/IV if you want good AF at f/8
On my 1D II you could get AF at f/11 if you used 400 f/5.6 + Kenko 1.4x + Canon 1.4 or 500 f/4 + Kenko 1.4x + Canon 2x. Haven't tried it on my 1D IV yet.
rgold1963 wrote:
Your 500f/4 with the 2XIII behaves exactly as my 400 DO does with the 2XIII. Hopefully Canon will release a firmware update to address this as it seems like the camera is quite capable of focusing at f/8 in somce of your other tests.
Ron
Or just use a 1.4X Mark III in combination with a Kenko 1.4X TC to get an effective focal length multiplier of 2X with your f/4.0 lens, at least for the time being as a work around.
thanks for doing the tests & providing the results here Jim! very helpful & much appreciated!
maybe someone else might be able to comment on this question as well, but any comments on the performance (speed vs consistency) & image quality between having 1.4x III + 1.4x DG vs the Canon 2x III on any of the Canon superteles?
(maybe i oughta pose the question as a separate thread?)
"Comment: if I want consistent AF performance at f/8, I'll use my 1D Mark IV."
You nailed it Jim.
If 800mm is not long enough and you can't get closer to your subject to fill the full frame, keep your Mark IV.
After all, the most valuable 1D X improvement over the 1D Mark IV is the new 61-point AF system. Adding third party extenders and shooting at f/8 would greatly reduce any AF advantage.
Fred Miranda wrote:
You nailed it Jim.
If 800mm is not long enough and you can't get closer to your subject to fill the full frame, keep your Mark IV.
After all, the most valuable 1D X improvement over the 1D Mark IV is the new 61-point AF system. Adding third party extenders and shooting at f/8 would greatly reduce any AF advantage.
Exactly. If we let ourselves become obsessed with that "reach" at the expense of some key qualities this latest technology offers, then might as well use this sorta thing....plenty of "reach" there :
A bit off topic as it involves the 5DIII and a 1.4x TC at f8. I’ve had good success with the 5DIII + 400mm f5.6 + a taped pin Kenko DG 1.4x TC. Note that this was shooting outside with fairly decent light. I saw that you taped your lens here, I have both a Canon 1.4x II and Kenko 1.4x DG. I leave the Kenko permanently taped as I’ll sometimes stack the two TCs with the 500mm f4.
Seems as if Canon shot themselves in the foot, by disabling F/8 autofocus in the 1D X. Kenko 1.4x DG teleconverters not "Canon". are selling like hot cakes.
