300mm 4L and 10D and 1.4ex

[Doom1701e]

Ok, so my new 300 4L is arriving tomorrow with my new 1.4 extender. I am just wondering, with the 10D's 1.6 magnification, does anyone know what the focusing distance becomes when the lens is mounted on the 10D? The lens on the 1.4 extender on the 10D? The lens on the 1.4 extender on a 35mm camera? Just wondering if anyone know this off hand. Thanks!

[RichardtheSane]

Are you looking to find out the minimum focusing distance or the effective focal lengh?
Your question is not that clear I'm afraif :(

[CyberDyneSystems]

The minimum focus distance for the lens as advertised is not effected by either the 1.6 "factor" OR the 1.4X t-con :)

Is this what you are looking for?

[Doom1701e]

Ya! Thats what I am looking for!! (Focus distance)

[Doom1701e]

New question. Is the IS on the 300 4L still operational with the 1.4 extender attached?

[slin100]

Yes. The 300D and 10D can AF up to an effective aperture of f/5.6.

[CyberDyneSystems]

....and YES the Image Stabilizer will work with the 1.4x too :roll: :wink:



...and the 2X for that matter :) but Auto Focus won't work with the 2X on the 10D.

The 300mm f/4 and the 1.4X are a near perfect 420mm f/5.6 lens on the 10D :)