Telephoto convertor lens - Zoom

Are there any telephoto convertor lens for a G6 that will zoom the focal length ?
I.E a 2X convert that will take 35-140mm to 70-280mm ?
All the convertors I've seen so far only work at the camera's full zoom.
Rgds - David

You put the converter in front of the cam with the corresponding adapter. The zooming function of the lens is not affected.
The only thing you'll probably get is vignetting when going wider.
The wider you go, the more vignetting you'll get...

Most good teleconverters like the Canon TC-58, the Olympus TCON-17 and the Kenko LD20T only really give usable pictures for the vignetting reason from somewhere like 2.5x zoom until fully zoomed in. The bad ones might be even worse.

Unfortunately it's a fact of life that has to be taken into consideration.

If you want to know which teleconverter to get and which ones are good ones, read the respective threads on the forum like this one.
A good starting point normally is to view the threads by rating.

Best regards,
Andy

Many thanks for the very quick replies.
"vignetting" is the point where you start to look down a tube ?
Rgds - David

It's exactly that.

The first signs are that the corners of the image are darker than the center, but with the teleconverters, you will literally look down a tube when using them zoomed out.

Best regards,
Andy