I recently picked up a K-3 to upgrade from my K-5. I figured I'd post a few comparison RAW's with my other camera's for those who are curious.
I'm happy with the camera, it's very very close to the K-5 for low light but with a big boost in resolution. More importantly though it's much faster to operate and more refined in general, a great upgrade. And for 796 with the grip a steal.
Here's some RAW captures with the K-5, X100s and RX100 for comparison. Note the RX100 and X100s only go to ISO 6400 in RAW.
I used each camera's meter to 0 EV and ISO 6400. Some very different settings where picked. In general the K-3 and X100s are a much brighter exposure and used longer shutter settings while the RX100 and K-5 picked faster shutter and are a bit darker. Had I used a standard shutter they would have all been similar in exposure.
Overall noise for the K-5, K-3 and X100x are very very close. The noise looks worse on the K-3 at full magnification but great at normal crops. It's very much like a 24mp version of the K5. The X100s exposes much brighter with it's meter than any of the others. Had I used -.5 EV or so the shutter speeds would have fallen in line with the K-3 as would the exposure. The little RX100 is a great point and shoot as you can see from it's much smaller sensor.
I should add the JPEG engine on Fuji is far far better than either the K-3 or K-5 , I keep the Pentax's in RAW and the Fuji to Jpeg. Sony's JPEG engine is the worst however turning everything to that smooth plastic look if you get anywhere near a high ISO. All of them produce excellent low ISO shots with the K-3 and X100s being the best. Fuji honestly does have some mojo in the colors of those jpegs and you really need to work the Pentax RAW's to get them where you want it in post.
35mm equivalent or as close as I could get it was used for each. DA* 16-50 for the Pentax's.
K5 1/50 5.6
K-3 1/30 5.6
X100s 1/20 5.6
RX100 1/60 5.6
K-3 X100s
K-3 K-5
K-3 RX100
Last edited by LeeRunge; 11-30-2014 at 04:06 PM.