Teleconverters help

[ronaldinhoaditya]

Hey guys...i have a Canon 7D and a 70-300mm f4/5.6 lens...i am an amateur photographer and take a lot of wildlife...i am planning to buy a teleconverter , i am new to this thing so could youll please tell me the pros and cons of buying a teleconverter and if i did which one i should buy...

[oldwolf]

Is it the L lens?

Here's the one that my wife and I use:

PRO30014XDGXC Kenko Teleplus Pro 300 DGX AF 1.4x Teleconverter for Canon EOS

Works great. She's got the 70-300mm L lens and uses the teleconverter on her 5D Mk II. I use it on my 7D with a Sigma 70-200mm f/2.8. Neither of us have had issues.

We bought that one from a recommendation on a website. From his review (he took it on safari), it's the only one that fits the 70-300mm L and allows it to autofocus.

Anyway, no complaints about it and we've used it often enough. Just be aware that it will cut your lowest apeture so you won't be able to get f/4 our of the 70mm end.

Good luck.

[cbowley2]

Originally Posted by ronaldinhoaditya

Hey guys...i have a Canon 7D and a 70-300mm f4/5.6 lens...i am an amateur photographer and take a lot of wildlife...i am planning to buy a teleconverter , i am new to this thing so could youll please tell me the pros and cons of buying a teleconverter and if i did which one i should buy...

Just bear in mind using a tc that takes you over aperture 5.6 will lose the ability to use autofocus.

for example a 2x tc will double aperture so not bad for a 2.8 lens

[sk66]

Originally Posted by cbowley2

Just bear in mind using a tc that takes you over aperture 5.6 will lose the ability to use autofocus.

for example a 2x tc will double aperture so not bad for a 2.8 lens

I thought it was "above f/8"...
I use the same 1.4 as OldWolf...works fine.
I'd avoid 2x TC's with your lens..in fact, unless yo are spending near $600 for a 2x it's probably not worth getting regardless of what you are putting it on...

I had a sigma 2x for use on Sigma lens (manual focus)..I now have the Nikon 2x TC III...it works great but they all have their issues.

Besides the light reduction of a TC, the "aperture" is "weird". On your lens @ f/4 it will report f/8 (for 2x) and will gather light like it was set at f/8, but it will have the DOF of f/4. If you want the DOF/sharpness of f/8 from your lens you have to go to f/16!

[Preeb]

Originally Posted by sk66

I thought it was "above f/8"...
I use the same 1.4 as OldWolf...works fine.
I'd avoid 2x TC's with your lens..in fact, unless yo are spending near $600 for a 2x it's probably not worth getting regardless of what you are putting it on...

I had a sigma 2x for use on Sigma lens (manual focus)..I now have the Nikon 2x TC III...it works great but they all have their issues.

Besides the light reduction of a TC, the "aperture" is "weird". On your lens @ f/4 it will report f/8 (for 2x) and will gather light like it was set at f/8, but it will have the DOF of f/4. If you want the DOF/sharpness of f/8 from your lens you have to go to f/16!

I've got the Canon 1.4x II Extender and I use it with my 70-200 f4 L IS and the auto focus works fine. They did say that the 2x would not let my f4 lens auto focus, but I never actually tried it.

[Don2325]

Has anyone in the forum tried using a teleconverter with an 18-200 zoom? Does the 2x give you the equivalent of 36-400?

[OsmosisStudios]

Originally Posted by Don2325

Has anyone in the forum tried using a teleconverter with an 18-200 zoom? Does the 2x give you the equivalent of 36-400?

It wont mount, and even if an off-brand one does, it'll likely bash into the rear-most element of the lens at some point. You'd lose autofocus and optical quality would be craptastic to boot.