[amp]

Maybe a silly question, but just want to be sure I'm getting the most out of this lens.
When I have the 135 m f3.5 on my k3 the f-stop doesn't show up on the screen. The only way to control, or even use it, the aperture is to change it on the lens. Right? Additionally, it must be in Av mode. Correct? I ask because when I change the aperture I don't see any change in shutter speed. Is that normal? Overall, I like the results I've gotten, but I want to be sure I'm using it correctly.
Any info/advice is appreciated.

[Scintilla]

If you use a Pentax-M lens in Av mode, it will only ever shoot wide open. To actually have it stop down the lens to the aperture you select on the ring, you need to switch the camera to full manual (M) mode.

But, since the camera can't detect when you change the position of the aperture ring, it doesn't know it needs to change the shutter speed and/or sensitivity -- until you hit the green button, which should force it to stop down and meter. (If it doesn't, then check your e-dial customization settings for the M mode.)

[Igelkotten]

Hi amp,
The trick is to use M-mode and the Green button to step down and meter befor you take the photo. There are several guides in this forum about this. Follow the link below and you will enjoy the full potential of your M-lenses.

https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

[amp]

Thanks so much.
If I didn't ask, I'd never have known.

[erichope]

P.S It has been mentioned here before but: use a fixed ISO. It makes sense, of course, but it's easy to forget and you'll never get manual mode to work correctly otherwise. I've done it.

[amp]

Ok. Will do. Looking forward to results with the lens stopped down.
Thanks to all again.