Canon 400mm f5.6 with teleconverters?

[Vectisbirder]

Is anyone using a Canon 400mm f5.6 L lens with teleconverters, both 1.4x and 2x? If so, how have you found it? I know about the fact you need to tape the pins to get AF (I am using a 20D and 40D so I know it won't AF on these without taping).

My question relates to the image quality - how do you tc users find the IQ with the converters? Is there a degradation or is it acceptable? Would I be better off just cropping an image obtained with the bare lens?

I want to get a tc for my 400mm but I am not going to spend best part of £200 if I am just going to waste my money.

Cheers
'VB'

[Ollie]

Hi Fay

I have used mine with a 1.4 tc and the image quality is still good. A slight degradation but very acceptable. However taping the pins which does allow auto focus doesn't work all that well. The auto focus hunts a lot and I found it easier to use manual focus.

The converter I was using is a Kenko Pro 300. I haven't tried a Canon converter but from feedback I have had, the Kenko Pro 300 is just as good as the Canon and much cheaper. I rarely use the converter though as I don't like manual focussing for birds.

Have never tried a 2x converter on it.

[Vectisbirder]

Thanks Roger.

[glsammy]

The lens is good enough to work well with a 2X TC, providing it's very bright conditions. You'd be shooting at best at F11 and preferably F13. That to me is the biggest problem. I've not tried my 2X TC with mine yet. I intended to try it at Bempton Cliffs last May but forgot to take it with me.
As Roger said, it does work well with the 1.4XTC.

[Vectisbirder]

Thanks Graham. I am thinking more of the 1.4x now, as I won't be losing a whole two stops that way. I think I'd be using my tripod a lot more, though.

[Davy Crockett]

It's been a while since your posts on this subject, how did you go one with it all

I have just bought
Kenko Teleplus PRO 300 DGX 1.4x Canon AF Teleconverter
and allthough the write up says it is fully intergrated for use with canaon lenses i fine i can't lock on to some sujects.

PS i know about taping pins, but that dosen't seem to work either.

[johnf3f]

Originally Posted by Davy Crockett

It's been a while since your posts on this subject, how did you go one with it all

I have just bought
Kenko Teleplus PRO 300 DGX 1.4x Canon AF Teleconverter
and allthough the write up says it is fully intergrated for use with canaon lenses i fine i can't lock on to some sujects.

PS i know about taping pins, but that dosen't seem to work either.

Sorry but if you want AF to work anywhere near reliably then you need a camera with an AF system that will allow it. Taping pins etc will work to some extent and the old Kenko 1.5 T/c will af most of the time, but really you need an EOS3, EOS1v, EOS 1D or DS .
If you have a camera that will AF in live view then that will ok, it's a bit slow but it will work.

[Davy Crockett]

I have the 40D and 600D so it's back to the tape then and hope for the best

[glsammy]

I do use mine with my 7D but only on manual focus. AF simply doesn't work without taping and then unreliably.

[JB9302]

Originally Posted by Davy Crockett

I have the 40D and 600D so it's back to the tape then and hope for the best

Thought the DGX design negated the need for taping the 1st three pins ?

Julian