Thinking of a teleconverter for my 70-200 F4

[tarmac_chaser]

Haven't got the cash for a bigger lens at the moment so wanted some feedback on getting a teleconverter for my 70-200 F4L lens.

Am I going to lose any quality or aperture at full zoom? What would be the best teleconverter for this lens?

It's being used with a Canon 400D and mainly wildlife pics. Current range is good 90% of the time would just like that extra bit of zoom for the odd situation.

 

[wack61]

I bought one of the 1.4x kenko Pro 300 DG teleconvertors to use with my sigma 70-200 f/2.8 and it works fine, no loss as far as I can tell, if you go for one make sure it's the pro as they do sell cheaper ones IIRC if you go for the 1.4x it'll still Af as you only lose 1 stop so your F/4 will become a F/5.6 anything over F/5.6 won't AF so don't go for the 2x as you lose 2 stops with it making your F/4 an F/8 with no AF

 

[markta]

I have the combo of the 70-200 f4L plus the Canon 1.4x extender.

Erm...you do lose a little quality as a result of the extender, but not a great deal IMHO.

As stated above, you will lose a stop of light, so in effect, the lens becomes a 128-420mm f5.6L.

 

[StewartR]

Markta's maths is a bit wonky.

With a 1.4x Extender you have a 100-280mm f/5.6 lens which retains AF. Image quality is slightly degraded but still quite acceptable.

With a 2x Extender you have a 140-400mm f/8 lens which is MF only. Image quality is degraded further. Not recommended.

 

[tarmac_chaser]

Thanks for the advice. I'm thinking I might not worry about a teleconverter then, as at 5.6 it would slow it a little and quality would suffer a little. If I see a cheap Kenko going I may get it just for experimenting.

Looks like I need to save for a long range lens!

 

[wez130]

I've got the 70-200 F/4L and kenko 2x tc, it's actually alright in decent light, as an example, heres a shot i took at 400mm(200 x2) on it, as far as i remember it's just resized from original shot....