Canon EOS-1D X AF at f/8 with the Kenko 1.4TC

[Marsu42]

Canon EF 70-300 f/4-5.6 L + Kenko 2x (effectively @ f/8-11) = Slow/difficult to lock focus

... a 1.4x tc is the absolute max for the 70-300L unless you mf, but imho the iq with the 1.4x Kenko is "just" ok so I wouldn't want to try a 2x.

[Childeric]

What a surprise !

I mentioned exactly that almost two months ago ;-)

http://www.canonrumors.com/forum/index.php?topic=7980.msg145491#msg145491

By the way, it seems to me that overexposure is more than one IL, and the correct aperture is reported by the 1dX, strangely.

[Peerke]

Maybe known, but anyway.

A Kenko 1.4 PRO 300 DG won't do the trick on my 7D with 400 5.6. I guess you need a DGX  .

Just had a look on the Kenko site. It should not be possible according to them. They state that:

"Most Canon EOS camera bodies are programmed to shut down auto focus if the calculated effective aperture for the lens and teleconverter is smaller than f/5.6, the Kenko Teleplus PRO 300 converters work the same way"

[SambalOelek]

Canon EF 70-300 f/4-5.6 L + Kenko 2x (effectively @ f/8-11) = Slow/difficult to lock focus

... a 1.4x tc is the absolute max for the 70-300L unless you mf, but imho the iq with the 1.4x Kenko is "just" ok so I wouldn't want to try a 2x.

In fact, I found that the bare lens performance at 300mm is only okayish, which is somewhat disappointing considering the max aperture. I have two of these so I may run a quick check to see if there's any discernable difference.

[Marsu42]

In fact, I found that the bare lens performance at 300mm is only okayish, which is somewhat disappointing considering the max aperture. I have two of these so I may run a quick check to see if there's any discernable difference.

The 70-300L is not the sharpest lens on the block, but it is a is good tradeoff between short length, reasonable weight (!), L build quality, nice bokeh, very good af performance and moderate price - don't forget the price difference to the 70-200/2.8 and tele primes. But you are correct, the 1.4tc solution definitely doesn't produce professional grade shots @100% crop, it's just "nice to have" for the low cost of the Kenko.

But since you mention it: there are qc issues, for the iso crops they had to get another sample (see link below). But at least my sample is very sharp @300mm on crop, i.e. using the lens' center. If it isn't it's simply a shutter speed issue because with low shutter speed + IS I can get good pictures, but for max. sharpness it's still 1/500 or faster.

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=738&Camera=453&Sample=0&FLI=0&API=0&LensComp=738&CameraComp=453&SampleComp=1&FLIComp=0&APIComp=0

[Arthur Morris]

It seems that firmwares later than 1.02 disable to ability of the 1DX to AF at f/8 with the  Kenko Teleplus PRO 300 DGX 1.4x AF Teleconverter with all the accompanying benefits....

Does anyone know if it possible to save the firmware that is on the camera? 

Arthur Morris www.BIRDSASART-Blog.com

[Arthur Morris]

I don't understand the need to dial in -1 stop compensation?  Doesn't the light loss caused by the TC automatically result in a lower metered exposure?  I'm confused

It looks as if you nailed this one....

[Arthur Morris]

Maybe known, but anyway.

A Kenko 1.4 PRO 300 DG won't do the trick on my 7D with 400 5.6. I guess you need a DGX  .

Just had a look on the Kenko site. It should not be possible according to them. They state that:

"Most Canon EOS camera bodies are programmed to shut down auto focus if the calculated effective aperture for the lens and teleconverter is smaller than f/5.6, the Kenko Teleplus PRO 300 converters work the same way"

Childeric,  Not to be a pain but that is not exactly what you wrote. In fact, what you wrote is not at all what I wrote .

[Marsu42]

It seems that firmwares later than 1.02 disable to ability of the 1DX to AF at f/8 with the  Kenko Teleplus PRO 300 DGX 1.4x AF Teleconverter with all the accompanying benefits....

Holy crap, so it's like "We own you and all your camera bodies" because if af @f8 doesn't work w/ the Canon tc, it shouldn't work at all? Argh - I read this is the same with the latest 5d3 firmware, can anyone confirm this?

[Arthur Morris]

Agree. Not very nice at all.  I have written some folks at Canon for confirmation.... Will advise.

Arthur Morris/www.BIRDSASART-Blog.com

[danski0224]

Might be time to scratch off the 1DX from my wishlist too... cheaper that way anyways.

 

[neuroanatomist]

It seems that firmwares later than 1.02 disable to ability of the 1DX to AF at f/8 with the  Kenko Teleplus PRO 300 DGX 1.4x AF Teleconverter with all the accompanying benefits....

Does anyone know if it possible to save the firmware that is on the camera? 

AFAIK, it is not possie to save the currently-installed firmware.  It is possible to downgrade/roll back to an earlier firmware, but doing so requires the updater for that version, and the first downloadable 1D X firmware is 1.0.6. 

I expect that Canon Service could roll a 1.0.6-updated 1D X back to 1.0.2, whether they would is another question...

Artie, I read the comment about 1.0.6 apparently breaking the f/8 AF with the Kenko 1.4x TC - has that been confirmed by others?  If so, that's very unfortunate...

[Arthur Morris]

What I know is based on the comments of several others both on my blog and on the BPN post here: http://www.birdphotographers.net/forums/showthread.php/102647-1DX-Canon-800mm-f-5-6L-IS-Kenko-Teleplus-PRO-300-DGX-1-4x-AF-Teleconverter (I believe...)

[neuroanatomist]

What I know is based on the comments of several others both on my blog and on the BPN post here: http://www.birdphotographers.net/forums/showthread.php/102647-1DX-Canon-800mm-f-5-6L-IS-Kenko-Teleplus-PRO-300-DGX-1-4x-AF-Teleconverter (I believe...)

Should point out that Phil on BPN stated, "I have a Kenko 1.4X Teleplus Pro 300 sitting in my dry box for years."  It's been mentioned in a couple of places that the f/8 AF on the 1D X seems to work only with the newest DGX version of the Kenko 1.4x, not with the older DG version (therefore possibly not with the even older vanilla Pro 300 version). 

So, perhaps there's some hope...

[Childeric]

Maybe known, but anyway.

A Kenko 1.4 PRO 300 DG won't do the trick on my 7D with 400 5.6. I guess you need a DGX  .

Just had a look on the Kenko site. It should not be possible according to them. They state that:

"Most Canon EOS camera bodies are programmed to shut down auto focus if the calculated effective aperture for the lens and teleconverter is smaller than f/5.6, the Kenko Teleplus PRO 300 converters work the same way"

Childeric,  Not to be a pain but that is not exactly what you wrote. In fact, what you wrote is not at all what I wrote .

Well i didn't say what you quote, Peerke did.

What I wrote here back in July was that my 1dX did AF at f/8 with this kenko pro300 adapter, that's all.