Pentax *ist DS
Review Date: June 23rd 2005
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Image Quality
All of the sample images in this Review were taken using the JPEG Best (3008 x 2008) mode, which gives an average image size of around 2-3Mb.
Noise
There are 5 different ISO settings available on the Pentax *ist DS which you can select at any time. Here are some 100% crops which show the noise levels for each ISO setting:
ISO 200 (100% crop) |
ISO 400 (100% crop) |
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ISO 800 (100% crop) |
ISO 1600 (100% crop) |
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ISO 3200 (100% crop) |
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The noise levels look very good at ISO 200-800, with some noise and RGB artefacts starting to appear at ISO 1600. ISO 3200 is very noisy and isn't really a practical option at all, but that is a very fast speed that you may never need to use anyway.
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 at the default sharpening setting of 0 (Standard) are slightly on the soft side with post-processing bringing out some extra detail.
Original 100% Crop |
Sharpened 100% Crop |
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File Quality
The Pentax *ist DS has four different file quality settings available, with ***: Best being the default option. Here are some 100% crops which show the quality of the various options, with both the pixel and file size shown in brackets.
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RAW (3008 x 2008) (9.81Mb) |
***: Best (3008 x 2008) (1.78Mb) |
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**: Better (3008 x 2008) (967Kb) |
*: Good (3008 x 2008) (541Kb) |
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Chromatic Aberrations
I had to look hard to find any examples of chromatic aberrations in the review shots taken with the Pentax *ist DS. They were only apparent in very high-contrast situations, such as the roof structure and bright white sky in the examples below. When they did appear, chromatic aberrations were at the edges of the frame and not too obvious at all.
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Example 1 |
Example 2 |
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Macro
The Pentax *ist DS offers a Macro scene mode, but as the *ist DS is a digital SLR it is the lens that determines how close you can get to the subject, not the camera body. The standard 18-55mm kit lens allows you to focus on a subject that is 25cms away from the camera respectively. The first image shows how close you can get to the subject (in this case a compact flash card). The second image is a 100% crop.
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Macro Shot (click to view full-sized image) |
100% Crop |
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Flash
The flash settings on the Pentax *ist DS are pretty standard - Auto, Flash on, Auto & Red-eye reduction and Flash on & Red-eye reduction. These shots of a white wall were taken at a distance of 1.5m.
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Flash Off - Wide Angle (27mm) |
Auto Flash - Wide Angle (27mm) |
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Flash Off - Wide Angle - Lens Hood Fitted (27mm) |
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Flash Off - Telephoto (83mm) |
Auto Flash - Telephoto (83mm) |
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And here are some shots of yours truly. The built-in pop-up flash underexposed the scene by about 1/2 stop of exposure. As you can see, neither the Flash On or Red-Eye Reduction setting caused any amount of red-eye.
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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 *ist DS maximum shutter speed is 30 seconds and there is also a Bulb setting (allowing you to open the shutter for as long as you like), which is great news if you're interested in night photography. The shot below was taken with a shutter speed of 15 seconds, aperture of f/11 at ISO 200. I've included a 100% crop of the image to show what the quality is like.
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Night Shot (click to view full-sized image) |
100% Crop |
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Overall Image Quality
The Pentax *ist DS produced images of very good quality during the review period. The 6 megapixel JPEG photos were soft out of the camera at the default setting and benefit from further sharpening in an application like Adobe Photoshop. Alternatively you can increase the sharpening setting on the camera or shoot in RAW mode and sharpen the files later on your computer. The Pentax *ist DS's best performance was with chromatic aberrations, which hardly appeared in any of the test shots - only the faintest purple fringing effects could be seen in very high contrast situations. It also handled noise well, with ISO 200-800 displaying little noise and ISO 1600 also useable. Macro performance was average with the supplied 18-55mm lens, although with this camera being a DSLR you could always treat yourself to a dedicated macro lens. The built-in flash had a tendency to underexpose quite a lot indoors but there was no evidence of redeye. With a maximum shutter speed of 30 seconds and a Bulb setting, the Pentax *ist DS offers great potential for creative night shots.
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PhotographyBLOG is a member of the DIWA organisation. Our test results for the Pentax *ist DS have been submitted to DIWA for comparison with test results for different samples of the same camera model supplied by other DIWA member sites.