Sigma Multiplier

[22littlereasons]

I find my 70-200 f2.8 sigma a little short for covering soccer and was thinking about a lens extender. I've read alot about Canon extenders here, but does anyone have any experience with sigma extenders.

[J.A.F. Doorhof]

Hi,
The canon convertors will not work.
I own a Sigma 1.4x convertor and love it, it has almost no (or at least I can't see it) picture degradation and is small.

I also tried a 2x extender but found the light loss to be a problem but also that picture still looked nice.

Greetings,
Frank

[DocFrankenstein]

Hi,
The canon convertors will not work.
I own a Sigma 1.4x convertor and love it, it has almost no (or at least I can't see it) picture degradation and is small.

I also tried a 2x extender but found the light loss to be a problem but also that picture still looked nice.

Greetings,
Frank
Are you sure about the canon converters not working? :?

[J.A.F. Doorhof]

I believe the Canon convertors only work on their L-glass.
But I could be wrong offcourse.

Greetings,
Frank

[Cadwell]

I believe the Canon convertors only work on their L-glass.
But I could be wrong offcourse.

Greetings,
Frank

You're wrong. The Sigma EX and the Canon EF convertors are completely interchangeable (I have / had both). They also suffer from the same limitations in terms of only working with lenses with recessed rear elements, number of stops you lose and their effect on AF speed.

Don't bother with either manufacturers 2x convertor for sports use. According to Canon "The EF 2x or 2x II reduces lens drive speed by up to approximately 75%." (Source GETTING THE MOST FROM YOUR EOS-1 CLASS DIGITAL SLR - Chuck Westfall). My experience is that a 2x extender drops the focus speed to the point where tracking fast moving subjects doesn't work very well. The 1.4x extender seems OK.

[22littlereasons]

When you say "They also suffer from the same limitations in terms of only working with lenses with recessed rear elements and in terms of the number of stops you lose." Do you mean the 1 stop loss for 1.4x and 2 stop loss for 2x rule I've been reading about around here?[/quote]

[Cadwell]

When you say "They also suffer from the same limitations in terms of only working with lenses with recessed rear elements and in terms of the number of stops you lose." Do you mean the 1 stop loss for 1.4x and 2 stop loss for 2x rule I've been reading about around here?

Yes. Also see the comment I added about AF speed.

[CyberDyneSystems]

http://photography-on-the.net/forum/showthread.php?t=41922