In perfect light, with an excellent lens, shooting RAW then you'll find even the *ist-D produces stunning shots (and that's at 6mp). Even for 18x12" prints the difference can be difficult to tell. Between the K10D and K20D at ISO100 there is some difference, but it's not massive.

However, the K20D is noticeably better at low light compared to any of the other bodies. Mostly this is down to a CMOS sensor, whereas all other models are CCD. Also as a consequence the image dynamic range is different with the K20D, and the CMOS seems to handle low light situations better (the CCD seemed to saturate blue at very low levels).

You'll get a few extra useful features as well, e.g.
1) Longer battery life
2) Ability to finely adjust the focus of all your lenses
3) Exposure compensation available in "M" mode as well
4) Live view (handy at times but not a "make-or-break" feature IMHO)
5) Pentaprism viewfinder. When I've compared pentamirror to pentaprism, the prism was always much clearer!

With the K10D I'd be happy to shoot up to around ISO1000 in RAW, but with the K20D I'm fine up to ISO2500 (even 3200 at a push).

So, if you're doing landscapes and portraits in a studio then there won't be a huge difference. If you're pushing the camera to the limit in different lighting conditions, then you'll notice a fine improvement in the K20D.

Certainly, some of the current deals for the K20D and GX20 seem extremely tempting

Matt

It's probably a good idea to get a better definition of what you mean by "low light"

Give us an exposure reading and that will help (e.g. ISO3200, f/2, 1/30)

In all situations you need a good point of reference for focussing - something with some contrast. Personally, I find that I always use centre-only focus point, and make use of the dedicated "AF" button (and disable the "AF on halfpress of shutter" in the custom menu). That way I can point to something that I know has some contrast, then reframe and shoot.

But let's start with the exposure reading to give us an idea of what you are looking at

Matt

That was quick work Don

Payment received fine Don I'll email the PDF when I get home (about 3hrs to wait!)

Graham, you still need some hardware for Argyll to use - which may explain the crashing. It worked fine on 32bit Vista though.

On Windows there is a fiddly installation for some hardware devices. But the Huey was a breeze under Windows (it already appears as a HID USB device, whereas some of the others, Spyder included, appear as custom devices and need to have their device driver assigned to the Argyll HID drivers).

The author of Argyll has been extremely helpful in sorting out various minor glitches and issues. It may be worth checking the Argyll forum for any news on x64 issues with Vista.

Failing that... get yourself a Mac (I'm a long-time Windows user and programmer, but loving the iMac 24" - wish I'd switched ages ago!!!)

Matt

Don - have PM'd you back BTW - it covers much, much more than just P-TTL Tried to cover pretty well every flash mode on the Pentax with almost any flash! (Phew!)

Jon - I meant ArgyllCMS + dispcalGUI runs on Mac/Windows/Linux
The other advantage you'll have of using Argyll is that you can install it on as many machines as you want

Links:
http://www.argyllcms.com/ - AgyllCMS
http://hoech.net/dispcalGUI/ - dispcalGUI

On the Apple Mac it's an absolute doddle to install - especially with a Huey (it's a fair bit harder with a Spyder). Just unzip the Argyll files into ~/bin/Argyll_V1.0.4, then install dispcalGUI - and when asked, point it to ~/bin/Argyll_V1.0.4/bin

You can just click "Calibrate & Profile" (or you can change the "Profile Type" to "LUT" near the bottom). You'll see a terminal window appear - just press "7" to continue onto calibration.

Pretty easy - but be warned the LUT profile is time consuming - and you should disable screen savers etc!
Leave the display on for at least 1 hour before starting, then allow about 1 or 2 hours for decent profiling.

It's not until you find a display that won't calibrate with the software supplied with the hardware that you realise just how good Argyll is!!

Matt

I've used the Spyder 1 Pro then the Spyder 2 Pro. Both were pretty good... then I discovered ArgyllCMS and dispcalGUI (Google for them). Both GPL/free to use software. Argyll produces some of the best colour profiles I've seen - and works with Spyder, Huey, EyeOne etc, etc.

Did a friend's laptop this week. He has a Huey Pro that wouldn't calibrate properly with the Huey software. Profiled using his Huey unit and used the "LUT" (colour look up table) profiling (rather than the more simplistic "Matrix/Shaper" profiling) - the profiling was quicker than the Spyder 2, and the result was fabulous!

If you can get a Huey for £34 then I'd say do that and use the free Argyll CMS + dispcalGUI

Additional advantage - it runs on Windows/Mac/Linux

HTH,
Matt

I have only found issues when the "AF on halfpress" is disabled in the custom menu. If you pushed the shutter button too quickly, then SR could blur the shot if it hasn't stabilised.

However, Pentax released an updated K20D firmware that fixes that issue
So now I leave SR on

Matt

Hi Kai - in my home town too
Matt