Hi, I've been exploring my new K3 and started down the fun road of manual lens acquisitions. I already had an SMC 135mm f3.5 prime knocking around from an experiment on a samsung nx camera, so this has been a test subject after getting the K3. I followed, mostly, the instructions I found on how to use a manual lens and have been getting some lovely results. But .... I've not used the green button stopping down and don't understand why my exposure seems to be ok notwithstanding.
When I have tried the green button, I'm not sure it does anything in particular. I can manually adjust the aperture from wide open to minimum and the shutter speed and iso, if on auto, remain unchanged between the two extremes yet the exposure is ok. I've seen reference to the aperture remaining wide open unless stopped down, but doesn't the manual adjustment of aperture on the lens do the physical adjustment of aperture and the camera can't do anything automatically to aperture? I noticed in some photos that even if the aperture is stopped down, there can be a narrow depth of field. So, I'm guessing I'm wrong about my assumption. Could someone shed some light. Is changing the aperture manually with the ring not altering the aperture as I thought. If it is changing as I thought, how come shutter speed and ISO remain the same even though I radically change the aperture with the ring?
As I say, had some nice results so far, but I'm keen to iron out this misunderstanding. I'm uploading a shot which clearly shows the narrowness of the DoF. If shot wide open, I wouldn't have expected it to be so narrow, yet I'm pretty sure I chose a narrower aperture to makes sure I got more in focus.