Using Canon X2 Extender With 300mm 2.8

Just out of interest, I have used the Canon 1.4 extender with no problems,
but have heard that when using the X2 extender the image quality suffers
quite a bit.

Anyone used a X2 extender with a 300mm f/2.8L IS? Would be interested to
know what the the final output is like (poor, acceptable or actually pretty
good).

 

It's hard to know what people mean by that.

If a person is expecting a lens with a TC to have as much high-frequency
sharpness and low-frequency contrast as without, then they are being
unrealistic and will declare that the TC is compromised, even if the TC is
doing the best it possibly can with the lens. The higher the
magnification, the more contrast and resolution are lost at the pixel level
(but not necessarily at the subject level, which is what is really
important when using TCs; after all, we use them to get our subjects to
cover more pixels (or grains) in the camera).

--

 

Shooting herons and wildfowl, I've had some really excellent results using
the Canon 2x MkII behind my old EF 300 f2.8L on a 30D in wintry conditions*.
(No heat shimmy.) I've also had poor results due to front focusing, and/or
heat shimmy. *Very difficult to tell any difference compared to using the
bare lens.

So far with a mint condition EF300 f2.8L IS I've yet to get any really good
results over medium distances in warmer conditions. The lens by itself is
excellent over short distances, and I suspect that it was seeing heat shimmy
over my normal longer birding distances. (I also use astro telescopes so
I'm familiar with the problems of "poor air" etc.)

I note from a recent posting on dpreview that one 1D MkIII owner has found
that he needed different micro AF settings when he added an extender.

 

Well, pretty much what you said, you lose contrast, although sharpness, CA
and barrel distortion too.

What I would like to know is whether the loss of contrast, sharpness, etc.
are poor, acceptable or pretty good with a lens like the 300 2.8L. Of
course it is a bit of an open request, because what one person may say is
pretty good, another may say that it is poor.

I have read this review (link below) that mentions using both the 1.4X and
the 2X extenders with this lens, however I would be interested in 'real
life' opinions from people that have used this combo:

http://www.the-digital-picture.com/Reviews/Canon-EF-300mm-f-2.8-L-IS-USM-Lens-Review.aspx

 

Considering you are starting with a "Holy Cow That's Good..."
lens..I'd settle for "Hey, not bad..." considering that with the 2x
TC, you've in effect created a 500mm f/5.6.

But since I don't own a 300mm f/2.8, YMMV...

Jay Beckman
Chandler, AZ
www.pbase.com/flyingphotog