Conclusion - Pros
- Good detail and color in JPEGs at base ISO
- Class-leading image quality in low light, very good retention of fine detail at high ISOs
- Good quality 720p video output (but Motion JPEG format produces large files)
- Decent build quality
- Quick and responsive operation
- Coherent user interface
- Very small dimensions for a DSLR
- 11-point AF system with flexible AF-point selection
- ISO range up to ISO 12800
- 4.7 frames per second continuous shooting (though buffer runs full quickly in RAW)
- Reliable flash exposure
- Excellent battery life with Lithium batteries (still good with Ni-MH rechargeables)
- Good viewfinder
- LCD color fine-tunable
- Extensive white balance options
- User-definable Auto ISO
- Distortion and chromatic aberration correction for DA and DFA lenses (also available in RAW conversion when using supplied software)
- Three-shot in-camera HDR capture
- Good selection of image parameters
- Digital Filters
- Choice of two RAW formats
- In-camera RAW conversion
- Good bundled RAW converter (based on SilkyPix)
- Very attractive price point
Conclusion - Cons
- Tendency to clip highlights in high-contrast scenes
- Relatively little RAW headroom means it is difficult to pull back blown detail even when shooting RAW
- No visible AF points in viewfinder
- Shake-reduction not too efficient
- AF in live view very slow (like most SLRs)
- Unreliable Auto White Balance in artificial light (but very good presets and WB fine tuning)
- No HDMI-connector
- ISO in movie mode is capped which can result in underexposed videos
In the Pentax line-up the K-x sits in the slot between K2000 (K-m) and the semi-pro K-7. While at first sight the new model is pretty much indistinguishable from the K2000, a closer look reveals that, from a features and specification point of view, the K-x has quite lot in common with the K-7, a significantly more expensive camera. It comes with the K-7's 11-point AF system and PRIME II imaging engine, along with its abilities to correct for chromatic aberration and distortion when using Pentax DA and DFA lenses. Add 720p HD video, ISO 12800 and 4.7 frames per second continuous shooting to the mix and you've got a, for the the K-x's very attractive price point, impressively well-specified camera.
Crucially the image quality does not lag behind the technical specification. The image output at base ISO shows good detail and colors but where the K-x really starts to shine is in low light. Its high ISO JPEGs are possibly the best of all current DSLRs with an APS-C size sensor; they certainly beat any of its direct competitors. The omission of visible AF points might be a serious drawback for some photographers but if you're not one of them with the Pentax K-x you can bag yourself a very capable entry-level DSLR at a bargain price.
In most shooting situations the K-x is capable of producing high quality image output. At base ISO JPEG images show very good detail and natural colors out of the box. The Pentax JPEG engine is doing a very good job at squeezing all captured detail into the camera's JPEG files and therefore shooting RAW does not produce a great amount of extra detail.
While the image quality at base ISO is generally very good, what we were really surprised about (in a good way) is the K-x's performance in low light. Up to very high sensitivities the Pentax output shows a very good balance between noise reduction and the retention of fine detail in JPEGs (raw output is similar to other cameras in its class). The K-x approach: leaning heavily on chroma noise with more lenient handling of luminance noise results in images with grainy, almost film-like noise characteristics, that show very good detail up to the very highest sensitivities. The K-x is surprisingly a lot better better in low light than its bigger brother K-7, and is no doubt one of the currently best performing APS-C cameras in low light.
However, there are a couple of negative points to mention as well. One of the K-x's main weaknesses is its habit to clip highlights. The problem is exacerbated by a tendency to overexpose high contrast scenes. The K-x also offers very little in terms of RAW headroom. Therefore shooting RAW will not solve the problem entirely. However, the ability to adjust the tone curve during file conversion helps to mitigate this issue. Your best bet though is to apply some negative exposure compensation when necessary.
All other image quality issues are of a fairly minor nature. Auto white balance in artificial light is not 100% reliable and, despite of focus confirmation, we also had a few slightly out of focus shots within our 1000+ sample shots; only a handful though and therefore well within acceptable limits.
All in all the K-x is perfectly capable of producing high quality image output, especially in low light. For beginners who primarily shoot in Auto mode the tendency to clip highlights can be slightly problematic. For everyone else it's controllable via some manual intervention.
The Pentax K-x is a typical entry-level DSLRs in so far that it is comparatively small and does not feature a large number of external controls. It one of the smallest DSLRs on the market and therefore a very good option for any photographer who prefers to travel light. Despite the small dimensions and the relatively simple user interface, handling and operation of the camera are straightforward and easy. Thanks to its good build quality and the relatively decent sized hand grip the K-x always feels stable and solid in your hands. All important functions are accessible either via hard buttons or the control panel (after a press of the INFO button). Together with the coherent menu systems this makes the camera easy to use, even for first-time DSLR-buyers.
The only, from our point of view, major negative point we have to mention is the lack of visible AF points in the viewfinder. While the 11-point AF-system itself is fairly flexible and configurable not seeing the focus points can be an important drawback for many users, simply because you never really know where the camera has focused. For everyday shooting this is not much of an issue but as soon as very precise or selective focusing is required you might run into problems.
The final word
The K-x is a very capable little camera indeed. Pentax has managed to squeeze what is, for this class of camera, an impressive feature set into the camera's minuscule, rather inconspicuous, body and the image quality, especially in low light, is the best we have seen so far in the entry-level bracket of the DSLR market. To put some icing on the cake, all of this comes at a currently, compared to the closest rivals, very attractive price point. To us the lack of visible AF points is the camera's only real drawback but if you can live with this omission you can't go wrong with the Pentax K-x.
Ergonomics & handling
Metering & focus accuracy
Image quality (raw)
Image quality (jpeg)
Low light / high ISO performance
Viewfinder / screen rating
Movie / video mode
Beginners wanting a well-featured DSLR on a tight budget, low light (high ISO) work
Not so good for
Movies, sports action
A very impressive DSLR with an excellent feature set and possibly the best high ISO performance in its class. The lack of visible AF points is a frustrating omission, but if you can live with that the K-x is a little cracker, and a bargain too.
Original Rating (December 2009): Highly Recommended
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