Page 1 of 1

EF 17-40 f4 + 1x4 teleconvertor

PostPosted: Tue Feb 06, 2007 1:40 pm
by click1808
Hi I'm a newbie to this ,but i would like to ask can i use a 1x4 conv with this lens or should i just buy a lens equivalent
Thanks :oops:

PostPosted: Tue Feb 06, 2007 2:41 pm
by gemmf
Personally I can see a point in making it a 24-56mm f5.6 lens. I think you'd be better off buying a different lens.

PostPosted: Tue Feb 06, 2007 5:09 pm
by philway

PostPosted: Tue Feb 06, 2007 5:48 pm
by gemmf
philway wrote:The answer is simply here : http://www.usa.canon.com/consumer/contr ... delid=7462


Not that simple, I'm afraid. It's true that you can only physically attach the Canon extender on certain Canon lenses, but there are ways of getting around to it (e.g. I use an extension tube for my 100mm macro), and teleconverters of other makes can be put on those Canon lenses. So you can use a converter on almost any lenses. I was just talking in more practical sense.

PostPosted: Tue Feb 06, 2007 9:11 pm
by philway
With an extension tube, the focus to infinite is lost and I don't think the Canon 17-40 f/4L USM becoming a good macro lens.

Another link about EF extender specifications : http://www.usa.canon.com/app/pdf/lens/L ... rt_new.pdf

PostPosted: Tue Feb 06, 2007 11:35 pm
by sheila
IMHO, TCs should not be used as a substitute for another lens. I have the Sigma 1.4x which I rarely use but when I do, I lose sharpness, even with good Canon glass.

Cheers
Sheila

17-40

PostPosted: Wed Feb 07, 2007 6:31 pm
by click1808
I here what ya saying ,thanks y'all i'll be getting a 24 -70 f2-8
l8r
be cool