OK, I reposted with a couple of "REDO"s for ISO 100 and ISO 6400.

http://moringello.com/public/K5_vs_K7_ISO.html

Tripod, WB the same, double-checked contrast, sharpness, etc... (although should not affect RAW),
made sure SR was off. Used LiveView with ContrastDetection for focusing.
I believe everything was as close to constant and consistent.

The focusing sharpness is now very close for both K5 and K7.
Since the tripod mounts were slightly different position on each camera, the last set might have focused slightly different -- need to build a custom rig or use laser guide to line up better, who knows.
Anyway I think I got them more in-line this time as well.
But WB is a little bit off, but much closer.

I also posted the ISO 6400 images with some processing.
K5 used about 25 for luminance and color noise reduction. The K7 required 100% but still looks pretty rough.

FYI, I noticed I said if you click on the initial images that you'll see 100% crops. That wasn't quite true.
I missed something and you have to additionally click on the [Download] link at the upper-right of the larger image. This will display the full sized 100% crop image.

My first time using iWeb, sorry about that. Nice program for quick mockups, but overly simplistic without a lot of control.

Hmmm, maybe. But I don't like to blame the equipment until I really make sure its not my fault.

I suppose I could use LiveView with contrast focus. My guess is that lens calibration would not fall so much into play as the focus is occurring via the sensor itself.

I have not read much on that focus mode (I rarely use Live View), but I wonder if that would be a reliable way to tell if the standard focusing is off or not. Any ideas?

Yeah, sorry some more details..
All shot in RAW. As stated no extra processing above LightRoom3's defaults.
100% crop converted to JPEG at 100% quality.
The images were at F7.1, various ISO and shutter-speed adjusted appropriately.
Baseline exposure: ISO 100 @ 1 second. (for both tests, thus brighter light test is more well exposed)

If time is on my side this weekend, I'll give these a second go and double check the focus and WB before I tear everything down.

Yeah, not quite sure why. Both on auto white balance. But I do see that the color is consistently a bit different than the K7 under various environments. I guess I'll have to take them both outdoors and play with different white balances at some point. (If I'm going to keep my K7 as a backup, it won't be very good if the balance is inconsistent across the board)

Not really sure about the focus issue either. I agree the K5 seems softer. Camera was on auto focus, so it should have "fixed" itself if I was off on one. I may go back and re-do a few key frames and see if I can figure that part out. Especially ISO 100 where I do most of my work. (ergh!!)

I actually like the K7 up to ISO 800 in the brighter light. In the real world I've done well up to ISO 1000 in daylight and even with stage lighting, so at least things are consistent there.

I've been locked up in the house and work for the week. By the weekend I hope to get some daylight photos and see how the quality holds up between them there.

Anyway, I like the side-by-side compare of noise, regardless of slight softness and color issues.
I hope it is still of some slight interest to someone.

Just got my K5 a couple of days ago. Really haven't had much chance to play hard with it, but had to do a quick ISO test between it and my K7.

Have to say the K7 isn't really all that bad and perhaps not all *too much* worse than the K5 in good light.
But I will appreciate and be able to use the expanded ISO and other features of the K5.

I have two sets of tests.
One in natural lighting near a bay window - about 4pm. So not too bright but also before lighting conditions changed within the two minutes to take the photos.
The other is under fluorescent lighting in the basement. This lower light shows more severe artifacts with the K7 at higher ISOs.

Otherwise for each, the aperture remained constant.
Shutter speed adjusted to compensate for change in ISO.

Anyway, I hope someone else finds this interesting...
I added no processing above what LightRoom3 does on its own.

http://moringello.com/public/K5_vs_K7_ISO.html

http://moringello.com/public/K5_vs_K7_ISO_LowerLight.html

If you click on the thumbnails, the 100% crop images will be displayed.
I hope they give a good idea of the noise and detail.

FYI, brand new K5 does the same thing, but perhaps a little quicker. Hard to catch the aperture closing.
So it certainly seems to be an intended behavior, even if introduced with some firmware update on the K7.

My guess? ... some sort of calibration is made to make sure the lens aperture ring is working or that it is in the 'A' position.

Not that I had much doubt, since the bodies are nearly identical, but I was pleased to find that the Eye-Fi Pro X2 8GB card works just fine in the Pentax K5.

Still playing with it, as I just got it a few hours ago, but so far it seems like a great camera.

Actually, in the end I wish there was a way I could add honest commentary on why I like one over the other.
There are a lot of issues between the two OSes that users should be aware of. Sadly, the zealots will bash and flame people for making any criticism regardless of how true it might be and the worthwhile comments get drowned in fanatic rants.

I will have to look up the page I found years ago on how to prepare to move from Windows to a Mac. It was pretty honest about both the bonuses and pitfalls of converting... if I can find it I'll post or PM the OP.

he, he, yeah I bet! I have Win 7 x64 on my desktop for software testing... but then I am in the security software field and because it is so restrictive it is considered "safer". So many of the problems that a 64bit kernel introduces is considered a good thing. Although I bet it can make development a royal PITA. (Of course, programming in .NET, mixing with C++ code and libraries is no picnic in a 32bit system either!)

I think you've not added much petrol to flaming the Mac v.s. PC war.. Mac has similar issues if you run the Kernel in 64bit mode. Some drivers just won't work, etc...
Although I have not got into Mac kernel programming, so I'm not real sure how much better or worse Mac is that regard overall.

So wrong... killing someone would be a much lesser offense!

It is hilarious how some people cling to an OS with such fanaticism.
One can easily have fun pushing the "zealot button" and making these threads go on for weeks.

There are plenty of reason to not buy certain brands of pre-built PC... Dell, HP, Toshiba, etc...
but if you're merely speaking of building your own PC with "quality" parts and putting Windows 7 on it... not much reason to choose one over the other.

Price out equivalent hardware, bundled software and support, you'll find the PC is rarely much less.
Windows 7 64bit is now supremely stable, regardless of the overly overt UI. I would say it is finally as stable as Linux and Mac.

I really would not find a reason to suggest one OS over the other beyond personal preference and comfort level in using the OS.

My personal comfort level, start up Terminal or PowerShell and let the UI sit idle.
No practical reason for a graphical OS.
The OS is simply a means to an end -- running the applications you need.