...Capability, continued from page 1

New to the Sony Alpha A100 is the DRO which can adjust the brightness levels of photographs before being converted to JPEG. Like the Lo80 and Hi200 modes, the DRO is designed to help with dynamic-range problems. Recall that a camera can only capture a small dynamic range compared to reality. The DRO has 3 modes: Off, Standard and Advanced. Obviously, in the Off mode, the DRO does nothing. The Standard mode adjusts the brightness levels of the image based on the overall image contrast and brightness. The Advanced mode analyses the image and adjusts it differently depending on local brightness and contrast.

The DRO is both powerful and dangerous. The power of the DRO is that it can easily produce pleasing images from high-contrast subjects with shadow and highlight details. The weakness of the DRO is that its effect is hard to predict and may be detrimental to the mood of an image. For example, a high-contrast scene can be rendered relatively flat, thus removing some of the photograph's punch. Also, the DRO cannot fill-in details which have not been captured. Note that the DRO works by modifying the camera's internal RAW conversion used to produce JPEG images. Hence, DRO does not affect RAW images other than influencing exposure.

The white-balance options of the Alpha A100 are similar to most digital SLR cameras. The automatic white-balance option is fixed while any preset and even custom white-balance can be adjusted on a green-to-magenta scale. The presets have 7 positions along the scale, while the custom white-balance has 19. When calibrating custom white-balance, this camera actually reports the Kelvin temperature and the Green-to-Magenta bias. This is useful to return exactly to a previously measured white-balance.

The exposure-mode-dial of the Sony Alpha A100 has 11 positions. Among those are the typical Program (P), Aperture-priority (A), Shutter-priority (S) and Manual (M) modes. There is also an Auto mode which is similar to P but prevents access to some functions. The last remaining positions are for the following scene modes: Portrait, Landscape, Macro, Sports, Sunset and Night portrait. These scene modes affect the way exposure is chosen and image parameters such as color-mode, contrast, sharpness and saturation.

The Auto-Exposure-Lock (AEL) button can be customized in 4 very useful ways. It works either by holding or by toggling. In Hold-mode, the exposure is locked until the AEL button is released. In Toggle-mode, the AEL is locked until either the AEL button is pressed again or the camera enters playback mode. The Toggle-mode is the easiest way to expose for stitched panoramas. The AEL can either use the current metering-mode or spot metering. Having the AEL-button use spot-metering provides a quick way to access spot-metering when faced with difficult lighting. Relative to exposure, a brilliant option is whether Exposure-Compensation (EC) affects ambient or flash+ambient exposure. In ambient-only mode, EC brightens the entire scene including the background. In flash+ambient mode, EC can affect flash output to change the illumination of objects within its range.

This DSLR supports the standard drive modes plus 3 bracket modes. In continuous drive mode, it can shoot an unlimited number of JPEG images or up to 6 RAW images. Continuous shooting speed is always 3 FPS. The self-timer can trigger after 2 or 10 seconds. With the 2-second self-timer, the mirror is automatically locked-up. Wisely, the 10-second self-timer is reset after each use which avoids the common mistake of forgetting to reset it. The bracketing modes are: single-step exposure bracket, continuous exposure bracket and white-balance bracket. Each bracketing mode takes 3 shots with either a small step or a large step. The small step is 0.3 EV for exposure-bracketing and 5 mired for white-balance bracketing. The large step is 0.7 EV for exposure-bracketing and 10 mired for white-balance bracketing. Single-step bracket requires the shutter to be pressed for each image in the bracket. Continuous bracket takes all 3 images continuously while the shutter is being pressed. The white-balance bracket is done virtually by taking a single shot and saving it with 3 different white-balance biases.

Given these special features it is clear that the Sony Alpha A100 was designed to simplify the work of photographers. Most importantly, this DSLR is one of the few to provide control over dynamic range. While the Alpha's DRO uses processing to attack the problem, the Fuji Finepix S5 Pro's SuperCCD SR provides a hardware solution. Dynamic range is one of the biggest limitations of digital camera technology and definitely deserves an article for itself.

Usability – How easy is it to use?

The shutter-release on this DSLR is a standard 2-stage release. The halfway point is distinct with a moderate amount of travel until the shutter is released. Some like this because it is hard to accidentally take a picture, some do not because they feel it takes longer to release the shutter. In single-shot focus and DMF, half-pressing the shutter locks the focus and exposure. Focus can also be locked separately by using the spot-focus button located at the center of the 4-way controller. There is also an AEL button to lock exposure before the shutter is half-pressed.

Ergonomically, the Sony Alpha A100 is great. It has a deep hand-grip with a small recession for the index-finder to keep it securely in place. On the camera's rear, an inwards curvature prevents the thumb from slipping off to the side. Together this makes the camera exceptionally easy to hold. The A100's only control-wheel is located just in front of the shutter-release. On the rear, the very important EC and AEL buttons are reachable with a small movement of the thumb. Speaking of buttons, every one on this camera is relatively large and has a durable feel. Even with thick gloves on, this camera's controls were all useable. The entire camera feels solid and well balanced.

The A100 has an average size penta-mirror viewfinder with a bright and clear view. The eyecup is large and also surrounds the previously mentioned eye-start sensor. The eye-start sensor ensures that there is no bothersome LCD glare when looking through the viewfinder. This is one feature that is hard to live without once you get used to it! Unfortunately, there is only one other current DSLR which implements this feature, Canon's Digital Rebel XTi

Exposure parameters are changed using the control-wheel. In P mode, the control-wheel selects between equivalent aperture and shutter-speed combinations. In A, S and M modes, the control-wheel changes a single exposure parameter. In M mode, the other parameter is changed by turning the control-wheel in conjunction with the EC button. In all other modes, this combination is used to apply exposure-compensation. The AEL button can also be used to modify aperture and shutter-speed simultaneously to maintain the set exposure.

The control-wheel is also used with the function-dial (Fn) to change image parameters. The Fn-dial is a great way to control many parameters without having to enter the menu system or overloading the camera with buttons. It works by rotating the dial to the desired parameter and then turning the control-wheel while pressing the Fn-dial's center button. The Fn-dial controls metering, flash-mode, flash-compensation, focus-area, focus-mode, ISO, white-balance, white-balance preset, DRO and DEC. Some parameters on the Fn-dial require the use of the 4-way controller to select between groups of sub-parameters. For example, the DEC parameter is split between color-mode and three image-parameters. Switching between the four requires using the 4-way controller. While the ISO setting is being changed, its value appears in the viewfinder status bar. It would have been better if it could be changed completely while looking through the viewfinder by providing a dedicated button.

Like all modern DSLR cameras, the A100 has a dedicated playback button and an image review option. When an image appears for review, it can be immediately deleted, zoomed-in or have its luminance histogram displayed. All the same options are available in playback mode as well. During image playback, the control-wheel can also be used to iterate through images without changing the zoom or display options. This is an effective way to compare the same area across a series of shots. The A100 offers two ways to zoom into an image. First, there is the traditional way which is operated by directly changing the zoom factor and scrolling around the image. Second, there is an area-navigation way which works by moving and resizing a selection rectangle over the image. When the selection rectangle is in the desired position, the LCD can be made to see only the selected area by pressing a button. This approach allows zooming into a specific feature more rapidly than the traditional way.

There are three options for the LCD (which serves as a status display in shooting mode): off, simple and detailed. Obviously, when off the display shows nothing. The simple display shows basic shooting information using a very large font. The detailed display uses a medium font to display more information including modified image parameters. A display button to the left of the LCD iterates through all three modes. Our impression is that photographers will either be interested in the simple mode or the detailed mode, but rarely both since the latter is a superset of the former. For that reason it would be better if the display button was simply an on/off switch and the simple or detailed view could be chosen via a setup-menu option. Presently , when switching between the status display and having the LCD off, the user is required to press the button an extra time to bypass the undesired mode.

The Alpha stores images in sequentially numbered folders. Each folder can contain 9,999 images but a new folder, numbered sequentially after the last one, can be created at any time using the setup-menu. When playing back images, the display button optionally allows to navigate between folders.

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