Using a Teleconvertor

If i use my 2 x teleconvertor on my KR i have to use manual focus . The camera asks me to set focal length on switch on (like for a normal manual focus lens) what focal length should i select ?

2x the focal length of the lens used.

what's if a zoom is used ?..

Have a look at the scale showing focal length and adjust accordingly.

I would just set it to the max of the zoom in use and test to see how it performs over the lower ranges of FL.

Best regards

Ok guys thanks for the answers