Pentax K10D vs Sony Alpha A100

Battle of the stabilized 10 megapixels DSLR cameras!

Usability

Usability is more subtle than performance. It includes design, ergonomics and features. Features that form part of usability are those which help photographers with the creative and technical process of photography. Among non-DSLR cameras, there are lots of features which do not fall into this category like world-clock, direct-printing, website publishing, etc. Digital SLR cameras have lots of usability features, but some manufacturers like Nikon and Pentax generally pack more of them. The Sony Alpha A100 may not have the most but it does pack several unique and very practical features.

In terms of body design, both the A100 and the K10D are rather good. The K10D and A100 have excellent hand-grips, the former being wider and the latter being deeper. Which one feels more comfortable most likely depends on the size of your hand. Without loosening pressure on the camera's back, several important buttons can be reached using your thumb. On the K10D, those are the EC, AF and AEL buttons, although that last one may require shifting your grip a little. On the A100, those are the EC and AEL buttons. Since the Sony's buttons are larger, they are easier to press while wearing gloves. Both these DSLRs have an easily accessible front control-wheel. Once again, the Sony's is easier to use with gloves because it has bigger notches. This may not be an issue for most people, but if you do take pictures where gloves are required, it is something to keep in mind. Another point with regards to gloves is that the K10D's memory and battery door compartments are more difficult to open. This is a reasonable compromise considering that DSLR's weather-sealing.

The K10D also has a second control-wheel on its back (above the EC and AF buttons) and a green button (near the shutter-release). Both of these are put to great use and, consequently, provide more efficient access to certain functions compared to the A100. Particularly, in A and S modes, the second-control wheel can be used to directly change ISO sensitivity and the green button can be used to automatically select the ISO. The green button can also be used to reset the exposure parameters to their metered values in both P and M modes.

Sony Alpha A100 - 0.83X Magnification

Pentax K10D - 0.95X Magnification

The K10D's pentaprism viewfinder is both bigger and brighter than the A100's pentamirror one. The difference is particularly noticeable in low-light. Coverage is at 95% for both though. Both cameras also feature a high-resolution 2.5" LCD for reviewing images. The Sony Alpha A100 has an eye-start sensor which turns its LCD off while the viewfinder is in use. This is a timesaving feature which nearly eliminates the need for the LCD activation button. Another thing that the A100's LCD does well is that it stays on while settings are being changed. As for the Pentax K10D, its information screen disappears as soon as a setting is changed. On the other hand, the K10D has a top-mounted LCD which can be used to change most exposure settings. Some important settings, such as white-balance, cannot be seen on the K10D's top LCD and therefore require using the rear LCD. The top-mounted LCD position is generally more useful while using a tripod but not necesarily for hand-held photography. With the Sony, all settings can be changed and seen from a single location which improves efficiency

Although basic capabilities are the same, these two DSLR cameras show different philosophies with their extended and unique features. The Sony Alpha A100 tends towards more automation addressed at various photographic situations. The Pentax K10D takes the opposite approach by providing more direct controls to the photographer.

Pentax K10D	Sony Alpha A100

The first place to notice this is on the mode dials. While both cameras feature the standard Automatic, Program, Shutter-priority, Aperture-priority and Manual modes, the Sony adds six scene modes. Each scene mode is pre-optimized to Sony's liking for particular subjects. Instead of scene modes, the Pentax has five additional modes, including a user-programable mode. The most unique modes of the K10D are its sensitivity-priority mode and its shutter-aperture-priority mode. The former mode selects aperture and shutter-speed automatically based on a chosen ISO sensitivity. The latter selects ISO sensitivity based on a chosen aperture and shutter-speed. Note that even in aperture-priority and shutter-priority modes, the K10D allows direct access to ISO sensitivity using a control-wheel.

Image parameters can be changed directly on both cameras in terms of color-tone, contrast, sharpness and saturation. While the K10D has more steps in its image parameters, each step is larger on the A100. We already mentioned that sharpness at +2 on the A100 is sharper than +3 on the K10D. The same is true for color saturation and contrast. In addition to those direct controls, the A100 features innovative ways to affect image contrast and therefore dynamic range. First, there are special keyed ISO settings: Lo80 and Hi200. These settings have a fixed effect designed to help with low-key and high-key scenes, respectively. Second, there is the Dynamic Range Optimizer (DRO) which adjust an image's tonality to enhance its apparent dynamic range. What is important about these features is that their result cannot be emulated by any combination of camera setting on the K10D, or any other DSLR, while shooting JPEG. However, with enough effort, they can be emulated using RAW conversion software. Speaking of RAW images, the K10D can develop them directly in camera and supports two such formats (Pentax's PEF and Adobe's DNG).

Although the K10D's white-balance system is more customizable than the A100's, its standout feature is an extremely useful white-balance preview. The white-balance preview works by taking a picture without storing it and dynamically changing its white-balance as the users modifies the camera's white-balance settings. This allows for a very accurate selection of white-balance without resorting to manual white-balance. With other DSLR cameras, including the Alpha A100, one has to go through a trial-and-error process until the results are pleasing.

There are plenty of other differences between these two 10 megapixels DSLRs when it comes to customization. Two particularly useful features of the K10D are its Program-Line and its customizable Auto-ISO. The program-line gives control on how the Program mode chooses its shutter-speed and aperture combination. This can be customized to favor fast shutter-speeds, narrow apertures, the lens' optimal aperture or average settings. The Alpha also has some very useful features: EC effect, AEL button customization and Eye-Start AF. The EC effect option selects whether EC affects ambient illumination only or ambient+flash illumination. The AEL button can be customized to use the set metering mode or spot metering and to behave as a hold-button or a toggle-button. Each of these options improves efficiency in specific situations. The Eye-Start AF option lets the camera start focusing before the shutter-button is half-pressed without using continuous auto-focus.

The last, but not least, aspect of usability is the availability of modern lenses. Although Pentax has been in the camera business for longer, Sony currently produces more lenses. Even so, both these companies have far fewer lenses than Canon and Nikon.

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