Patrick Sparkman
07-15-2012, 09:40 PM
As noted in this thread http://www.birdphotographers.net/forums/showthread.php/100220-Kenko-1-4X-TC-5D-Mark-III-Questions, we have been trying to find a teleconverter that works with the 5DIII and allows autofocus with the 800 f5.6. I purchased the Kenko 1.4X MC4, and the 2X MC4 to test, along with the Tamron AF 1.4X and SP AF 1.4X. The Kenko 1.4 MC4, and both Tamron Teleconverters will not work with the 5DIII and 800 combo. All three cause the camera to lock up which means that the camera thinks it is receiving an error from the lens. But the Kenko 2X works with the 5DIII, and reads out the correct aperture and focal length in the Meta data. It will even autofocus through the viewfinder in good light. Both the 1.4 and 2X Kenko's work fine with the 5DII and the 800, and the 1.4 works with the 70-200 2.8, and 70-300L. Overall a very frustrating experience, but I did want to do an optical test of my own to see how they stack up against the Canon Teleconverters.
Here is how I tested. I put two dollar bills on a flat piece of gaterboard, and used the LensAlign base to make sure the board was perpendicular to the camera. The pictures below show the results of the bare lens along with the Kenko 1.4, 2X, and both Canon 1.4III and 2XIII teleconverters. I used the 5DII for this test, since the 5DIII won't work with the Kenko 1.4. This shouldn't be an issue as these were shot at 200 iso, and they perform practically identical at that iso. Everything was of course tripod mounted outside in variable overcast conditions and I moved the target to get the same framing with each combination. I don't know the exact crop shown, but it was to get an idea of the relative sharpness. These images were imported into Lightroom 4 with the neutral camera profile and everything set to zero including sharpening and noise reduction.
As expected adding a teleconverter reduces sharpness and contrast. The Canon and Kenko 1.4's look almost identical in these crops, but the Kenko does vignette pretty significantly. If only it worked with the 5DIII, I think we would have a winner as it autofocuses well with the 5DII. In fact, it seems to work as well or better than I remember the 1DIV with Canon 1.4III combo. Things change when we get to the 2X however. The Canon 2X is a little worse than the 1.4's as expected but the Kenko 2X is significantly less sharp, especially at the edges. I don't think that I would be happy with the results from that combination.
So in summary, I am returning the Kenko 2X, and both Tamron's. One note: the Tamron's appear to be almost identical to the Kenko's and probably have the exact same circuit board. I am keeping the Kenko 1.4 though to use with the 5DII/800 combo as well as the 70-300 5DIII combo which I will talk about in another posting. Here are my conclusions in nice table form:
Canon 1.4 III - No autofocus with the 5DIII and 800 - (unless you tape the pins then it is somewhat unstable) Sharpness is good
Kenko 1.4 MC4 - Locks up 5DIII with the 800 but autofocuses with the 5DII Sharpness is good
Canon 2XIII - No autofocus Sharpness is pretty good
Kenko 2X MC4 - Works with 5DIII and 800 Sharpness is not very good
Please let me know if you have any questions, and if anyone else has any other ideas. I might order the Sigma 1.4. Does anyone have any experience with the Sigma 1.4 and the Canon 5DIII with Canon lenses?
Here is how I tested. I put two dollar bills on a flat piece of gaterboard, and used the LensAlign base to make sure the board was perpendicular to the camera. The pictures below show the results of the bare lens along with the Kenko 1.4, 2X, and both Canon 1.4III and 2XIII teleconverters. I used the 5DII for this test, since the 5DIII won't work with the Kenko 1.4. This shouldn't be an issue as these were shot at 200 iso, and they perform practically identical at that iso. Everything was of course tripod mounted outside in variable overcast conditions and I moved the target to get the same framing with each combination. I don't know the exact crop shown, but it was to get an idea of the relative sharpness. These images were imported into Lightroom 4 with the neutral camera profile and everything set to zero including sharpening and noise reduction.
As expected adding a teleconverter reduces sharpness and contrast. The Canon and Kenko 1.4's look almost identical in these crops, but the Kenko does vignette pretty significantly. If only it worked with the 5DIII, I think we would have a winner as it autofocuses well with the 5DII. In fact, it seems to work as well or better than I remember the 1DIV with Canon 1.4III combo. Things change when we get to the 2X however. The Canon 2X is a little worse than the 1.4's as expected but the Kenko 2X is significantly less sharp, especially at the edges. I don't think that I would be happy with the results from that combination.
So in summary, I am returning the Kenko 2X, and both Tamron's. One note: the Tamron's appear to be almost identical to the Kenko's and probably have the exact same circuit board. I am keeping the Kenko 1.4 though to use with the 5DII/800 combo as well as the 70-300 5DIII combo which I will talk about in another posting. Here are my conclusions in nice table form:
Canon 1.4 III - No autofocus with the 5DIII and 800 - (unless you tape the pins then it is somewhat unstable) Sharpness is good
Kenko 1.4 MC4 - Locks up 5DIII with the 800 but autofocuses with the 5DII Sharpness is good
Canon 2XIII - No autofocus Sharpness is pretty good
Kenko 2X MC4 - Works with 5DIII and 800 Sharpness is not very good
Please let me know if you have any questions, and if anyone else has any other ideas. I might order the Sigma 1.4. Does anyone have any experience with the Sigma 1.4 and the Canon 5DIII with Canon lenses?