Newbee Question CANON 70-300 F4-5.6 IS

[eeyore]

but the canon converter cannot be used with the 70-300 - it physically doesnt fit , and as regards the kenko it is not a reasonable assumption that this will opperate in the same way as the canon as they are priced dramaticvally apart and in anycase the electrical contacts are different

it might make sense to contact kenko directly to explore compatibility , tho as i said using any converter with a lens with the max apperture of f5.6 is a dodgy proposition except in bright light ( unless you have a 1 series canon dslr whose autofocus will work at f8)

i agree that the IS is lens based but it needs to draw power from the camera battery , if the contacts for doi ng so arent present in the tc then it wont have power and thus wont be able to function

[Interpreter]

Originally Posted by eeyore

but the canon converter cannot be used with the 70-300 - it physically doesnt fit , and as regards the kenko it is not a reasonable assumption that this will opperate in the same way as the canon as they are priced dramaticvally apart and in anycase the electrical contacts are different

it might make sense to contact kenko directly to explore compatibility , tho as i said using any converter with a lens with the max apperture of f5.6 is a dodgy proposition except in bright light ( unless you have a 1 series canon dslr whose autofocus will work at f8)

i agree that the IS is lens based but it needs to draw power from the camera battery , if the contacts for doi ng so arent present in the tc then it wont have power and thus wont be able to function

Why doesn't it fit. If it is an EF lens it has the same mount. Putting any third party extender onto a Canon lens is not likely to improve the optics. (Unless it is a 24-105mm L lens, in which case anything should improve it!)

[glsammy]

Originally Posted by Interpreter

Why doesn't it fit. If it is an EF lens it has the same mount. Putting any third party extender onto a Canon lens is not likely to improve the optics. (Unless it is a 24-105mm L lens, in which case anything should improve it!)

It's quite possible that the physical construction of the TC will prevent it fitting. This is true with Sigma 150mm and the Canon 1.4XTC. It physically will not fit, the lens on the TC fouls the Sigma rear lens. This is not so though for the Kenko TC, that is made differently so it fits and works perfectly.
I've no idea if this is the reason the 70-300 can't work with TC though!

[eeyore]

graham beat me to it - that is precicely why the 70-300 is cant be used with a canon tc , and why canon issues the list of those that can