Comparing Cameras

It's easy enough to spot the differences between the various Pentax dSLR cameras when it comes to ergonomics and handling. What I would be interested in is a comparison concerning Image Quality (IQ). After all, you learn how to handle your camera, whether it has one or two wheels, or the buttons are placed differently.

In my understanding, the factors contributing to the IQ are
- Image Sensor
- Image Processor
- AF sensor/circuit
- AE sensor/circuit
- SR mechanism

So where do the various models (K100, K200, K10 and K20) differ, apart from the pixel count? What would I gain IQ-wise by switching from a K200D to a K20D?

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Best regards
Terry

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

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http://www.mattmatic.co.uk
(For gallery, tips and links)

Thank you for taking the time, Matt.

Apart from the useful extras, I understand that IQ-wise, the difference is mainly a better sensor (lower noise) in the K20D.

I would imagine that the other components are mostly the same (AF, AE and SR). At least, the AF seems to be the SAFOX VIII in all bodies. And I would also be surprised if the SR mechanism and the image processor were different.

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Best regards
Terry

Be surprised, because new models often have tweaked and improved components. Even the AF module that you mention may well have been improved as time has gone by. The image processing engine certainly has.

SR was also tweaked between the K10D, K20D and now the K7.

Constant progress.....

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Best regards,

John Riley

Tonal range is important. The K10D seems to have a bigger
range than the K20D.

My GX-20 goes very dark in the shadows in bright sunlight
wheras my K10D doesn't.

shim