TC?

Manchesterr

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Go on then, someone please explain this terminology to me.

I've no doubt it's going to be really simple, but I can't fathom it out.

I've noticed a few people posting about using a lens and a tc, but am unsure what it actually is / means.
 
its a device called a teleconveter,it fits between the camera body and the lens and increases the focal length. They are usually 1.4,1.5 and 2*.
They are not a magic bullet as depending on the lens to which they will affect image quality,they also cost between 1 and 2 stops of light which means that many cameras will not AF with some teleconveters.
 
its a device called a teleconveter,it fits between the camera body and the lens and increases the focal length. They are usually 1.4,1.5 and 2*.
They are not a magic bullet as depending on the lens to which they will affect image quality,they also cost between 1 and 2 stops of light which means that many cameras will not AF with some teleconveters.

Ah, I see. Thanks a lot!

so with a 70-300mm lens, I could effectively get up to 600mm?
 
Ah, I see. Thanks a lot!

so with a 70-300mm lens, I could effectively get up to 600mm?

You could indeed, but at the cost of two stops. If your lens is f5.6 at 300mm, put the x2 TC on and it becomes an f11 lens.
 
You could indeed, but at the cost of two stops. If your lens is f5.6 at 300mm, put the x2 TC on and it becomes an f11 lens.

So much to learn! Looks like this will be a long road :)

Thanks though for the info.
 
Also, a TC highlights any flaws in the lens so an already softish lens will become even softer, this is why people only tend to use them on pro quality glass.

Add to that, the issue of the aperture changing means that the camera has to try and focus as if it was almost in the dark - most cameras don't autofocus effectively with anything smaller than f/5.6
 
You could indeed, but at the cost of two stops. If your lens is f5.6 at 300mm, put the x2 TC on and it becomes an f11 lens.

Maybe

Canon TCs are only compatible with certain lenses and the 70-300 isn't one of them (even the L version i believe) and i think Nikon is the same with their TCs

You could hook up a 3rd party TC however we have another problem
Autofocus
Add a 1.4x tc and you lose a stop of light so your now 420mm f8 at the long end
Add a 2x tc and you lose 2 stops of light and now you are 600mm f11 at the long end

Speaking for Canon most bodies can only autofocus at f5.6 (the 1 series bodies work at f8) so as soon as you put either TC on you will lose AF.

You do hear of some people taping the pins on the TC so the camera dosn't know its there and will attempt AF anyway but it really slows down anyway.

And yeh, quality hits... I probably wouldn't bother with anything more than a 1.4x on anything other than L glass unless i really had a specific need.
 
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