Teleconverters

[bramley]

Hi all,

I'm thinking about getting a teleconverter for my 70-200 f2.8 lens (Canon). I know diddly squat about them however I think I would want a 2x converter at least as 1.4x wouldn't be long enough (this is on a 5D so full frame). Also I would want AF to work properly.

Canon seem to only offer two, should I be considering any other brands?

Anyone got any advice? Things to avoid? Recommendations?

Thanks

[matthew_h]

Dave,

Not directly relevant, but I have the Sigma 1.4x and 2x t-cons for use with my Sigma 70-200.

The 1.4x hardly has any detrimental effect on the usage at all. The lens stays sharp and the AF seems unaffected. The 2x slows the AF a fair bit though and it is a little softer. The moon shots I took last weekend were taken with the 2x on though and they were ok.

I would suggest that if you are going to do it then get the dedicated Canon ones to go with your lens as they will work the best.

[megy]

If its a F2.8 lens you will retain full function of the lens with a X2, F4 and you may loose some functions, but will retain them with a X1.4.

Cameras need to have(more often than not) F5.6 for these to work and a X2 will reduce the lens by 2 stops, and a 1.4 by 1 stop.

Think thats right anyway, no doubt I will get corrected if I am wrong.

Saying that, some of the cheaper X2 only reduce by 1 stop, teleplus that is.

[Captain Beaky]

I have the Canon x2 teleconverter to use with my 70-200L and 5D. It works well for me, all functions retained, though it is reputed to degrade the image more than the x1.4. You lose a couple of stops but that's one of the reasons I got the 2.8 with IS. Focussing is slower in low light.

I chose the x2 over the x1.4 because I felt that I could get away with a crop for a 40% focal length increase but for 100% I'd prefer an optical solution.

[bramley]

Cheers Matt - I agree, Canon one is probably the way forward.

Megy - ta. If AF works, I'm happy!

Captainbeaky - would you recommend the 2x then? I don't think I would use it that often but for the odd occasion it would give me 400mm for not a lot of money. You mention image degradation - does it bother you much or does it just mean the images are 'good' rather than 'excellent'?!

[Captain Beaky]

It sounds like your situation is similar to mine - I don't need 400mm enough to buy (and carry !) a dedicated lens but the teleconverter with the 70-200 gets me a pretty good impersonation of one when I do.

The image degradation doesn't really bother me, the images are still good.

[VxDuncan]

This is a good page:
www.nikonlinks.com/articles_teleconverter_review.htm

It's obvisously biased toward the superior system (Nikon) 80) but should give an idea.

Like my comment above, it's only one persons opinion though, and there's no scientific measurement taking place.

[Timmy2TARs]

bramley said:

Hi all,

I'm thinking about getting a teleconverter for my 70-200 f2.8 lens (Canon). I know diddly squat about them however I think I would want a 2x converter at least as 1.4x wouldn't be long enough (this is on a 5D so full frame). Also I would want AF to work properly.

I have the Canon 2x one with the same lens. Here are a few samples taken with the combo - were on a 300D body though. As someone else says, so long as you have the f2.8 you will still be able to use autofocus with the 2x. Apologies for the watermarks - I've copied the files from another site where I've had problems with theft.