Re: Extension Tube Question

[Godfrey DiGiorgi]

The Pentax 1.7x AF adapter does alter the maximum aperture information;

it shows my 300/2.8 wide open as f4.5

Very interesting! thanks john.

Godfrey

But it's the exception; I don't know of any other TCs that do this.  A

full AF TC, with the digital signal pin contact, is unlikely to be able to change aperture information; Pentax haven't released a specification

for how lens-to-body digital signals are encoded.