Sigma 2x Converter

[ingouk]

Hi,

i have a sigma 70-200 f2.8 EX HSM and a Sigma 135-400 f4.5-5.6.
to cut down on space used in my bagpack i was thinking of replacing the 135-400 with 2 x Converter for the 70-200.
Has anyone used a 2x converter on the 70-200? How is the quality of photos taken with it? I guess noone will have a 70-200 with a 2x converter and a 135-400 and can email me some test shoots. IS there a shop in london where one can rent a sigma 2x converter for a day to test it?
Any help would be appreciated.

[dhbailey]

Remember that with the 2x converter you'll lose 2 stops and thus the lighting situations you'll be able to shoot in will change.

I don't think you'll find the single lens, with and without the 2x converter, will be as satisfying as the two lenses you currently have. I realize that space and weight is an issue, but quality photographs and the ability to get that perfect shot is an important issue also.

A 2x converter won't necessarily give you the same photographic ability you currently have.

[Cadwell]

I suspect the end result is going to be quite close.

Both combinations will give 400mm @ f/5.6...

The 70-200EX lens is rated quite highly optically so although the 2x TC will
degrade it a bit, the comparison with the 135-400mm could be quite close.

The focus speed of the 70-200 will be slowed by the TC but then it was much faster than teh 135-400mm to start off with....

Sorry, I don't have any answers for you but it will be interesting to see what you come up with in the end.

[ScottE]

I have a Canon 70-200/2.8 and a Sigma 50-500. I also have a Sigma 1.4x APO teleconverter and Tamron SP AF 1.4x and 2x teleconverters.

There is almost no detectable difference between the perfomance of the Sigma and Tamron 1.4x teleconverters. I assume there would be no difference between the 2x teleconverters either.

With the Canon 70-200/2.8 lens with the 2x teleconverter the images are perceptably softer than with the Sigma 50-500.

I would never shoot the combination with the 2x teleconverter if I had the 50-500 available. However, I do carry the 70-200 + 2x as back-up when travelling. Sometimes when I take the 70-200 for low light conditions, I also bring the 1.4x and 2x teleconverters in case I need more telephoto length and I do not want to carry the bulk of the 50-500.