teleconvertor - quick Question

[Lynton]

OK, had a whizz through the manual for the K20d - nothing of any use, so I thought I would check the encyclopaedic knowledge that is TP.

I have a K20d and a 120-400mm Sigma. I have also borrowed an automatic 1.7 TC for Waddington. (By automatic I mean it allows the lens to still autofocus.)

When I switch the camera on it asks me to input the focal length of the lens (not sure why this info isn't carried through)

I assume I put in the original minimum focussing distance i.e. in this case 120mm???? Does it really make much difference?

Interestingly it asks the same with all other lenses a swell.

 

[arclight]

I had a K20d and the lens you are using.
The instruction sheet for the lens said that a teleconverter could not be used in the Pentax fit version (that was correct - I tried and the t/c did not fit correctly). However, things may have changed if you have a more recent Sigma lens.

I assume I put in the original minimum focussing distance i.e. in this case 120mm???? Does it really make much difference?

Interestingly it asks the same with all other lenses a swell.

That I do not understand. The K20d should automatically detect the lens.
You could try puting the camera back to the factory default settings via the menu in case you have inadvertently changed something to cause the problem.

 

[Lynton]

yeah I know the siggy Teleconvertor doesn't work but this one seems to if focussing on say a registration plate on a car 20 m away, but anything over 40m doesn't want to know.....

K20d does auto detect if I don't use the TC. It's when I use the TC it asks........ not a big deal more annoying than anything.........

Cheers

 

[arclight]

yeah I know the siggy Teleconvertor doesn't work but this one seems to if focussing on say a registration plate on a car 20 m away, but anything over 40m doesn't want to know.....

K20d does auto detect if I don't use the TC. It's when I use the TC it asks........ not a big deal more annoying than anything.........

Cheers

It was a Kenko converter I had then. It was not lock into place on the lens (was also too tight a fit on the camera for my liking).