The Pentax K20D: a RAW review

Concept: This review covers aspects of the Pentax K20D from the perspective of a landscape and a street photographer, shooting predominantly RAW files. I am not competent in and do not cover other domains, such as sports/action, photojournalism, studio, and flash.

This is also an interactive review: rather than leave you to try to sort out my biases from the facts, I provide full-size image files so you can form your own conclusions.

Procedural note 1: Feel free to contact me if I'm not addressing concerns you have or if you feel my methodology or analysis is in error.

Procedural note 2: Key images throughout this review have links both for a full-size JPEG version and the original RAW version for your evaluation. The JPEGs were processed from the RAW file in Lightroom using minimal settings, including linear curve, no NR, and no USM, then converted to JPEG in Photoshop at the highest level yielding a file size under 5 megabytes (usually level 10 or 11). The RAW files are mostly supplied as compressed DNGs, and range from 9 to 15 megabytes.

About printing: An obvious reason to buy a large megapixel camera is to make high quality prints. Some of the illustrations in this review have links to full-size, low-compression JPEGs, and some of these are print-ready. You can print these at the print size you normally use by changing PPI (pixels per inch). If you are contemplating buying a larger printer or having large prints made for you, you can also print just a portion of the whole image at the PPI setting you would use for a larger print.


The K20D is a semi-pro dSLR with a 14.6 megapixel APS-C format sensor. Here are the rest of the K20D's specs

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Fig. 1: K20D front view

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Fig. 2: K20D back view

The camera arrived on an early March Friday ... but so did a huge blizzard here in southern Ontario. This was somewhat frustrating given it's hard to take a sweeping landscape shot to evaluate a camera's fine detail rendition when falling snow is filling the air. So I contented myself with this shot through my bedroom window and moved on:

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Fig. 3: Storm a-brewing (800 ISO, handheld + IS) (Full size 3.9 mb JPEG.)

Handling – first impressions

In heft and size the K20D is right in the mainstream of 35mm SLRs going right back to the Nikon F – about 2 pounds and a hand's-length across. This is just right for me: enough heft to balance a fairly serious lens but not so much that I can't tote it for hours without noticing it's there. Also just right is the firmness of the various knobs and buttons; no chance of the mode dial or on/off dial rotating in the camera bag, for example. The finder is the same excellent pentaprism view Pentax has distinguished itself with since the first *ist D. The shutter release sound is meaty and about average in volume (meaning: not something you'd want to hear while a minister is saying "do you take this man to be your...").

The first task when getting a new digital camera is to plug the battery in the charger then plow through the manual. In this case over 150 action-packed pages of almost-reasonable English. (Actually, the main language problem is not that the manual was written by a non-native speaker; but that it was written in non-technical language. Kind of hard to talk about dynamic range or exposure latitude when you can't actually use either of those terms.) The manual is so long because the camera has so many features. What a camera is today is actually a full-scale software application, like the browser you're reading this in, running on a dedicated computer with some specialized and integrated peripheral devices like a sensor and a lens. Thus, using a modern camera has become as much a software learning-curve challenge as a hardware challenge. Now, you might think that you could just set the camera in manual exposure plus manual focus and away you go – but, no: you have to learn how to change the ISO, change the default 1 sec. display time for the image you just exposed on the monitor to something actually usable, etc., etc. One upside to this is the impressive range of customization options in the menu system.

One of the few perqs of doing a camera review is getting to grump and grouse about all the details that chafe one's sense of how things ought to be. I'm coming from the Pentax DS, having skipped the K10D, so much of what I say about the physical aspects of the K20D likely applies to the K10D as well.

(Naggy little) things that should not have been changed but were

Things that should have been changed but weren't

Things that should have been changed and were

Things that were changed and/or added that sort-a leave me scratching my head

An interesting addition that I'm not quite sure into which of the above categories it belongs is live view. Over time I assume I'll come to have an opinion on what to do with it, but so far no bells have rung. It's quite true that you can hold the camera at arm's length overhead and still see what's on the monitor, but I attend very few parades and rock concerts...

What's driving me crazy right now is finding the dinky AF, +/- (Exp. Comp.), and AE-L (Exp. Lock) buttons with my right thumb. Presumably my hand will get used to them in time.

How to take a picture with the K20D

Probably a topic of study for a lifetime, but here's what I've come up with so far, based on Av mode. I used the custom settings menu to assign EV comp and ISO to one scroll wheel and of course aperture to the other when the mode dial is set to Av. I also turned off AF on the shutter release button half-press, leaving it assigned to the AF button.

Rush shots: (no time to check exposure, etc.) I put the meter on pattern, the AF mode dial on centre, check the aperture if I have the luxury of that much time, press the AF button with the part of the scene I want to focus on centered in the the finder, compose, adjust ISO via scroll wheel if needed, then shoot.

More leisurely shots: I switch the meter to spot, switch the mode dial to User, which is Av with +3.0 EV/comp dialed in, meter off the brightest spot in the scene, check that my aperture is what I want for DOF push the exposure lock button (= ETTR or expose-to-right metering), then use ISO to get my shutter speed in the appropriate ball park. In theory I would compose next, then do focusing as above with the AF button but in addition select the appropriate focus point; in practice I am more likely to stick to the centre focus point.

It only sounds complicated...

That's it for the merely practical aspects of the camera. The rest of this review concerns what's near and dear to my heart: image quality, starting with resolution and acutance.