Pentax K-m Review
(also known as the Pentax K2000)
Review Date: December 1st 2008
Author: Mark Goldstein
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Image Quality
All of the sample images in this Review were taken using the 10M Best JPEG image size option, which gives an average image size of around 5Mb.
The Pentax K-m captured images of very good quality during the review period. This camera produces noise-free images at ISO 100 up to ISO 400, with significant levels of noise first appearing at ISO 800. The fastest speeds of 1600 and 3200 are undoubtedly noisy but still useable for small prints and web images. The Pentax K-m's 18-55m kit lens dealt very well with chromatic aberrations, with limited purple and green fringing effects appearing only at the edges of the photo in high contrast situations. Anti-shake is a feature that sets this camera apart from its competitors and one that works very well when hand-holding the camera in low-light conditions or when using the telephoto end of the zoom range. The built-in flash worked quite well indoors, with no red-eye and adequate overall exposure. The night photograph was very good, with the maximum shutter speed of 30 seconds and Bulb mode allowing you to capture enough light in all situations. The 10 megapixel images were a quite soft straight out of the camera at the default sharpening setting and ideally require some further sharpening in an application like Adobe Photoshop, or you can increase the level in-camera.
Noise
There are 6 ISO settings available on the Pentax K-m which you can select at any time if the camera is in one of the creative shooting modes. There is virtually no discernible noise at the slowest settings of ISO 100 and 200, and ISO 400 also looks fine, with some noise creeping in. More obvious noise and slight loss of detail is apparent at ISO 800, and at the fastest settings of ISO 1600 and particularly ISO 3200, image quality has deteriorated a lot. Here are some 100% crops which show the noise levels for each ISO setting:
ISO 100 (100% Crop) |
ISO 200 (100% Crop) |
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ISO 400 (100% Crop) |
ISO 800 (100% Crop) |
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ISO 1600 (100% Crop) |
ISO 3200 (100% Crop) |
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File Quality
The Pentax K-m has 3 different JPEG image quality settings available, with Best being the highest quality option. Here are some 100% crops which show the quality of the various options, with the file size shown in brackets.
10M Best (3.23Mb) (100% Crop) |
10M
Better (1.71Mb) (100% Crop) |
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10M Good (0.83Mb) (100% Crop) |
10M RAW (10.8Mb) (100% Crop) |
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Sharpening
Here are two 100% crops which have been Saved as Web - Quality 50 in Photoshop. The right-hand image has had some sharpening applied in Photoshop. The out-of-the camera images are a little soft at the default sharpening setting, and benefit from further sharpening in a program like Adobe Photoshop. Alternatively you can change the in-camera sharpening level in the creative shooting modes using the Custom Image menu option.
Original
(100% Crop) |
Sharpened (100% Crop) |
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Chromatic Aberrations
The Pentax K-m's 18-55mm kit lens handled chromatic aberrations very well during the review, with some limited purple fringing present around the edges of the frame in particularly high-contrast situations. Here are some 100% crops which show the typical chromatic aberrations that you can expect:
Chromatic
Aberrations
1 (100% Crop) |
Chromatic
Aberrations
2 (100% Crop) |
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Flash
The flash settings on the Pentax K-m are Flash On, Flash On + Red-eye, Wireless Mode and Off. These shots of a white coloured wall were taken at a distance of 1.5m.
Flash Off - Wide Angle (28mm) |
Auto Flash - Wide Angle (28mm) |
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Flash Off - Telephoto (82mm) |
Auto Flash - Telephoto (82mm) |
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And here are some portrait shots. As you can see, neither the Flash On setting or the Red-Eye Reduction option caused any amount of red-eye.
Flash On |
Flash On (100% Crop) |
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Flash - Red-Eye Reduction |
Flash - Red-Eye Reduction (100% Crop) |
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Night Shot
The Pentax K-m maximum shutter speed is 30 seconds and there's also a Bulb option for even longer exposures, which is excellent news if you're seriously interested in night photography. The shot below was taken using a shutter speed of 15 seconds at f/8 at ISO 100. I've included a 100% crop of the image to show what the quality is like. The camera takes the same amount of time again to apply noise reduction, so for example at the 15 second setting the actual exposure takes 30 seconds.
Night Shot |
Night Shot (100% Crop) |
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Anti Shake
The Pentax K-m has an anti-shake mechanism built into the camera body, which allows you to take sharp photos at slower shutter speeds than other digital cameras. To test this, I took 2 handheld shots of the same subject with the same settings. The first shot was taken with anti-shake turned off, the second with it turned on. Here is a 100% crop of the image to show the results. As you can see, with anti-shake turned on, the images are much sharper than with anti-shake turned off. This feature really does seem to make a difference and could mean capturing a successful, sharp shot or missing the opportunity altogether.
| Shutter Speed / Focal Length | Image Stabilisation Off (100% Crop) |
Image Stabilisation On (100% Crop) |
| 1/3rd sec / 28mm |  |
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| 1/3rd sec / 82mm |  |
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organisation. Our test results for the Pentax K-m have
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for comparison with test results for different samples of
the same camera model supplied by other DIWA
member sites.