First let me start of with whatever I am writing in this is in no way meant to be critical and is only my opinion of what I know about photography and what I see in your photos along with what I read in your exif settings.
The Pentax photo appears as though it was using the default Bright color setting on your K 30. If you had shot it with the color manager in Natural it would be closer to the canon. Plus you used 1 stop ISO difference 1600 with the Pentax vs 800 with the Canon. Then you have a +.70 Bias exposure with your Pentax and a -.33 with your Canon. You can't compare the two accurately without using the same settings. Even given that there will be some color difference. Each manufacturer's sensor handles some colors differently then sensors of a different manufacturer. As mentioned one way to compensate is to use the color adjustments in the color settings to achieve what you want to see. We wont even go into what your monitor does....LOL
There are other factors then this being shake reduction difference. One being the difference in camera lenses. To accurately compare how two cameras fair with shake reduction and sharpness you would need to compare each camera with an Identical lens. An Aspherical lens also will be different then a non aspherical lens. Lenses of different focal lengths will perform differently at the same distance due to an average lens being shot at the end of it's focal length will not be as sharp as an average lens being shot in the middle it's focal length. I would venture to say if you used identical Tamron lens on both cameras you would see a much different result. Then number two being the differences in shake reduction types one being in camera the other being in Lens. Which is better has been a debate for years. Pentax's shake reduction according to the manual does not do well at slower shutter speeds where as in lens reduction doesn't fair well at higher speeds. Neither one will compensate for too much motion blur.
Now lets talk about your exposure settings. Your exposure settings were way off to begin with. The Pentax at ISO 1600 with f5.6 & 1/8 shutter gives you an EV (exposure value) of +3 which would be great if you were shooting fireworks at night with timed exposure. You did lighten it up in camera with a .70 bias. and I would assume with your processing program. Now let's take the settings for your Canon ISO 800 F5.6 & 1/8th Gives you a EV of +5 which is 2 EV's higher than then what you used with your Pentax. A +5 Ev is normally indoor shooting with average light, indoor stadiums, flames, candles etc. I am not understanding why you used a -.33 bias exposure on an already under exposed photo. A much faster shutter speed would have aided in achieving better sharpness in both cameras. Here again you would need to have the other settings correct for you lighting also. for an example if your lighting was of an EV 14= hazy sunlight. Then to keep your depth of field of f5.6 then you would use an ISO of 100 and a shutter speed of 1/250 or you could use ISO 200 and 1/500. Lets say it's bright Sunlight or an EV of 15 with that then it would take an f5.6, ISO 100 and 1/1000 or ISO 200 and 1/2000. In each of these you would have more than likely achieved a better sharpness yield. To keep your exposure correct at ISO 1600/ f5.6 it would take a shutter speed of 1/8000 for hazy sun and bright sun,1/15000 which your camera will not do.
Exposure hasn't changed since the beginning of cameras especially with cameras being able to adjust them. If you use manual settings it is wise to learn what EV values are and start with what is correct for the light you are dealing with, then adjust for affect otherwise you might find yourself unhappy with a lot of your photographs. I don't know how much you know about exposure but this I found as a helpful reminder and I copied the charts and keep them as a reference with me.
http://www.fredparker.com/ultexp1.htm#Introduction
Last edited by Oldbayrunner; 12-05-2013 at 02:40 PM.
Reason: added