K100 super Adjust..

[motox]

In manual mode, wich button do you press (or hold down) to change apperture

Cheers Simon....Moto.x

[Culhwch]

I have the K200, so I don't know if it's the same, but it's the +/- exposure button (mine has a little 'Av' next to it). Worth a try, at least.

[Kym]

Yes Culhwch is correct, Pg 144 of manual.

http://www.pentax.jp/english/support/download_manual.html