Update on the: Canon EF 70-300mm L IS Lens and Canon EF 1.4x III Extender are Com...

Back in October Bryan posting this article about the Extender and the 70-300L lens partially working. Does anyone know if he's posted an update anywhere else? My searching has not been fruitful.

What additional info were you looking for?

In the last paragraph he stated that he'd put some ISO 12233 charts up and post what Canon's response is. I'll look at the charts page again and see if I overlooked it.

The ISO crops are there, just set the focal length drop-down to 420mm or 600mm.

I'd infer that Canon didn't respond directly, but they did remove the 70-300L from the lens list on the 1D X v1.1.1 firmware page, which is a response of sorts... Obviously it's not a supported combo, with the risk of damage to the lens or extender.

I figured it would probably be risky from what Bryan had wrote; I'd hate to risk my $1300 lens and a $400 extender. Thanks for the response.

You can try the Kenko extenders, they fit. If you already have the Canon extender, it might be a bit of a stretch to own both, but M_Six has posted some good results here with that combo


Arnt

Here was Bryan's news post that I think you are thinking of:

http://www.the-digital-picture.com/N...aspx?News=3266

After trying out both (Canon 1.4vii and the Kenko PRO300 DGX) extenders on the 70-300L (using a 5D3) here are a few of my observations,
- when the next family vacation comes, the 70-300L and the Kenko extender are coming, the Canon extender will stay at home.
- the Kenko reports the focal length correctly - Canon does not.
- it is difficult for me to tell the pictures apart from an IQ standpoint, but I am no lens tester like many here are!
- the Kenko auto focuses much quicker than the Canon (in the daylight that I was testing in).
- the Kenko can be used over the entire zoom range, as others noted, the Canon has a rubber bumper that needs to be inserted in the lens, and that can only be done when the zoom is over 250mm. I think the rubber bumper would keep extender glass from contacting lens glass, but I agree with everyone else, that it is a risk not worth taking!
-both extenders utilized autofocus (in the daylight) and provided acceptable IQ in my opinion.
-as always, the Canon extender appears and feels much better built, and has the rubber seal for water resistance.

I briefly compared the extenders on a 70-200 2.8 IS vii to get some more comparisons.
- IQ again seemed comparable.
- AF seemed faster on the Kenko.

Then I tried a 135L
- Kenko doesn't work at all...actually froze the camera and had to shut off and remove the batteries to get it going again!
- Canon extender works fine.

Has anyone compared the 70-300L and Kenko 1.4extender, to the 100-400? Might be interesting!
Thanks.