Originally posted by mikesbike Unless you had nudged your exposure comp or had your eye away from the VF, I can see no reason the camera chose a shutter speed causing under exposure for the 1st photo. Do you wear glasses? Any chance some side lighting got in past the glasses? The 2nd photo is what one would expect. In fact, better than what one would expect. With so much dark area, one would suspect the camera might over-expose the brighter areas.
It is a puzzle. I went through the obvious things when I noticed the issue. I took around 200 shots and about 20 were underexposed. Thus 10%. But, that's not correct, when I looked back at the images in more detail I haven't noticed any failures when I was just in walkabout mode (= no tripod and 1/100 or quicker).
I don't normally have preview switched on as I've learnt to trust the exposures (if in doubt I choose to bracket as required) - in fact I find I rarely check the exposures in camera for non-tricky shots. As more and more of my shooting is becoming tethered on my FF gear maybe I'm becoming complacent. I'll now switch it on for this lens/k-3 combination, which will catch any future problems.
I'll try and re-create the problem today as I've unexpectedly got a little spare time.
Whoops, forgot to say I don't wear glasses, but if the issue isn't a mechanical one (which seems unlikely as the non-tripod shoots seemed OK), then it was probably a quirk of the woodland shooting I was doing using a tripod. This used to be my core subject matter/technique.
Curious ...