2x converters for lenses - change a 300mm into 600mm...

Ninja_scrotum

Are these any good? Has anyone here had any experience with them?

Calina

What lens are we talking about? IF it is the Sigma 70-300mm DG APO, then to the best of my knowledge, you will not get a 2x TC to fit one.

If it's a 300mm 2.8 then can't help.

Ninja_scrotum

Calina wrote: »

What lens are we talking about? IF it is the Sigma 70-300mm DG APO, then to the best of my knowledge, you will not get a 2x TC to fit one.

Yeah that's the lens I have. Why wont any 2x tc fit it?

Calina

I can't remember the exact details but it was to do with some part of the lens being too shallow. The camera I had was a 350D. Someone inside in Conns explained it to me around 2 years ago. I was looking at a Sigma 2x TC.

In any case - as a general note that Sigma 300 is very soft at 250-300 anyway, and sticking a converter on it - if you could which like I said I don't think you can - will cost you at least one and probably two stops plus it'll be even softer.

TBH, I really don't know if it's worth putting a TC on anything slower than a 2.8.

Paulw

Some lenses won't accept some converters.

For the Canon 2x, you need a Canon white lens.

So, a 300mm f/2.8 becomes a 600mm f/5.6 lens.

Eirebear

Paulw wrote: »

Some lenses won't accept some converters.

For the Canon 2x, you need a Canon white lens.

So, a 300mm f/2.8 becomes a 600mm f/5.6 lens.

I thouht it was down to the different Canon Fittings?

Ef rather than EF-S?

Eirebear

Scratch that, ive just checked my own.

my 1.4 convertor only fits on my 200m f2.8, which while not "white" is an "L" lens.....which seems to have a far deeper fitting than the others.

quilmore

a 2x TC on your lens will mean your f/5.6 300mm will become a f/11 at maximum aperture and no camera will autofocus on that

Ninja_scrotum

Can't I focus myself?.... If it's a bright day it shouldn't be too hard.

Ninja_scrotum

This guy seems to speak highly of the Quantaray 2x converter, which fites on his 70-300mm

www.fearlesheart.com/reviews/qteleconverter.html

JMcL

Calina wrote: »

What lens are we talking about? IF it is the Sigma 70-300mm DG APO, then to the best of my knowledge, you will not get a 2x TC to fit one.

At least the Sigma 2x converter will work with this lens, I had one on the other week. I really wouldn't bother with this combo though, image quality is really ropey.

As is stated elsewhere, you won't get autofocus if the resultant max aperture goes over f5.6 (though I think Canon 1D bodies will do f8). You have to manual focus, and, at least on the 40D, the focus lights don't function - you have to rely on what you see in the viewfinder. You could use live view I guess, but that's not much use if you're after critters!

I've tried a Canon 2x on the Canon 100-400L also, which did actually give fairly decent results, albeit without AF, and f11 max aperture :eek:

mervifwdc

Paulw wrote: »

Some lenses won't accept some converters.

For the Canon 2x, you need a Canon white lens.

So, a 300mm f/2.8 becomes a 600mm f/5.6 lens.

not quite true. You can put a 2x onto a 135L giving you a 270mm F4 lens. Results are ok-ish.

Merv.

Ninja_scrotum

Well I got a 2x converter even though some of yez had doubts about it fitting on the sigma 70-300, and the auto-focus issues and all that....


I had a good go of it today. A tripod is almost a necessity when you're at 600mm... but I don't have a tripod.

This is a handheld shot at 600mm



http://www.flickr.com/photos/25754481@N04/2445735447/

It's a nifty little gizmo for 40euro. When I get a tripod, it's full powers will be known to all.

Gonna aim it at the moon one of these nights....