Advice

I have one of these http://www.adaptall-2.com/lenses/103A.html
Now the manual says use it set at F32 for A setting equivalent. So does this mean that i have to enable aperture ring use in the menu or not?
Also I have a Vivitar MC teleconverter 2x PK-A/R-PK. Does the use of this need the aperture ring setting altering too.
Finally does anyone have any experience of using tele converters? Do they have much impact on image quality?
Many Thanks

I assume from what you have written that you have a Tamron Adaptall 2 lens with a Pentax PKA fit Adaptor. If this is the case, and you have a PKA Adaptor, then you can set the aperture ring to the A/F32 position. If all is functioning correctly, with the aperture set to A/F32, you should be able to set aperture values from the camera body (as with any Pentax A Lens, set at A). If it functions ok, then you do not need to enable the aperture ring setting, as long as your lens is set to A/F32.

With your Vivitar teleconverter, if it is indeed PKA compatible and you use it with an Pentax A or equivalent lens, set to A, then in theory apertures can be selected from the camera body.

Teleconverters do reduce image quality and reduce light. The more expensive 7 element converters are better. Cheaper ones tend to have 4 elements and there are some very poor ones about. It is probably best to do some tests with and without the teleconverter, and then have a peep at the image quality.

Thank you very much Graham. I will now do some test shots. might even post the results on here