Sony DSLR-A100

Reviewed December 2006

Characteristics

Sony has given the Alpha 100 an APS-C format CCD that measures 23.6 x 15.8 mm. The CCD is composed of 10.8 million pixels, of which 10.2 million are effective to capture an image with a maximum size of 3872 x 2592 pixels. A total of three image sizes are offered:

• 10M: 3872 x 2592 pixels
• 5.6M: 2896 x 1936 pixels
• 2.5M: 1920 x 1280 pixels

Each of these image sizes can be saved in JPEG format, at either of two compression levels Fine, which compresses the image the least and thereby offers the highest JPEG image quality, or Standard, which uses a stronger compression, reducing the image quality, but allowing more images to be stored in a given memory space.

In addition, images can be saved in a proprietary RAW format with or without a JPEG (10M Fine) copy. Proprietary RAW files have a .ARW extension, and contain the raw image data produced by the CCD, without any post capture processing from the camera, but contain precise information about the camera's settings for the shot. Sony supplies Image Data Converter SR, which can be used to read the RAW files once they have been imported into a computer, and makes it possible to save them into a more common format.

The Alpha's CCD has a sensitivity that starts at 100 ISO, but it can be pushed to 200, 400, 800 or 1600 ISO. An Auto ISO mode is also offered, and it allows the camera to vary the ISO as required by the ambient light.

Two other sensitivity settings are also offered, each designed for specific conditions:

• Lo80: is designed to capture images with a dark ambiance (Low Key), and avoid loosing details in the shadows.
• Hi200: is designed to capture images with a bright ambiance (High Key) and retain details in the highlights.

The Alpha 100 uses a Minolta A type mount, which allows it to be used with Sony and Minolta lenses (some of the Sony lenses were originally designed by Minolta).

A shutter speed range covering from 1/4000 second down to 30 seconds is available with the Alpha 100, as well as an unlimited Bulb (B) mode (as long as there is a charge in the battery, approximately 4 hours) when the camera is set to the Manual mode. All images captured with an exposure time longer than 1 second can be automatically processed for noise reduction if the function is enabled in the menu.

Although many settings are controlled by buttons and dials on the camera, some are contained in the menu. The Alpha's menu is composed of four sections, each identified at the top of the screen by an icon.

The first section, , is the Recording menu. It contains options that are spread out over two screens:

• Image Size: offers the three image sizes mentioned above.
• Quality: serves to choose RAW, RAW + JPEG or one of the two levels of JPEG compression, Fine or Standard.
• Instant Playback: serves to select the length of time an image is shown on the monitor post capture (2, 5 or 10 seconds or Off).
• Noise Reduction: On or Off. Decides whether noise reduction is performed on long exposures

• Eye-Start AF: On or Off. Decides if autofocus and metering occurs when the proximity sensor under the viewfinder detects the presence of the user. This option consumes more power.

• Red Eye: On or Off. Controls the red-eye reduction system, which uses pre-flashes.
• Flash Control serves to set the flash metering mode:
  • ADI Flash: fires a pre-flash and calculates the exposure using the amount of flash light according the reflected light from the pre-flash, and the distance to the subject.
  • Pre-Flash TTL: fires a pre-flash and calculates the exposure using the amount of flash light according the reflected light from the pre-flash, but does not take into account the distance information.

• Flash Default: Autoflash (default) or Fill-flash. When the camera is set to Auto, P, or one of the Scene modes, and the flash is opened, the camera will fire the flash only if the camera decides it is necessary for the exposure. The alternative, Fill-flash, ensures the flash fires when it is opened.
• Bracket Order: decides the bracketing order (0/-/+ or -/0/+).
• Reset: returns all main functions to their default settings.

The second section of the menu, , contains Playback options, spread over two screens:

• Delete: to erase unwanted images, either one at a time, or all, or those selected for deletion from in index view.
• Format: formats the memory card, removing all images, including protected images.
• Protect: prevents the accidental erasure of images. Images can be protected one at a time, or all at once, or unprotected all at once.

• Index Format serves to select the index screen format: 16, 9 or 4 thumbnails per screen, or File Browser view, which displays 6 images on the screen from folder to folder, each folder being identified at the top of the screen by a tab.

• Slide Show: presents images in an automatic slide show with a 5-second on-screen time for each image.
• DPOF Set serves to select images for printing, either all images or those selected in an index view. Three sub-options are offered:
  • Date Imprint: prints the date on top of the image when it is printed.
  • Index Print: makes an index print of the images selected for printing.
  • Cancel Print: cancels all existing print orders.

The third section of the menu, , contains the customization options:

• Priority Setup: serves to decide whether or not the shutter can be released when focus has not been confirmed.
• Focus Hold Button: when using a lens with a Focus Hold Button, it can be set to act as a Depth of Field Preview button.

• AEL Button serves to set the way the AEL button operates:
  • AE Hold: maintains the exposure parameters while the button is held pressed.
  • AE Toggle: acts like a toggle switch, maintaining the exposure when pressed once, and releasing it when pressed a second time.
  • Spot AE Hold: while the button is held pressed the camera spot meters, irrespective of the current metering pattern in use, and holds the exposure.
  • Spot AE Toggle: acts as a toggle switch, using the spot meter to meter and hold the exposure when pressed once, and releasing it when pressed again.

• Control Dial Set decides how the Control Dial operates:
  • Shutter Speed.: the Control Dial changes the shutter speed in the Manual mode and varies the shutter speed in combination with aperture when the camera is used in Program Shift mode.
  • Aperture: the Control Dial changes the aperture in the Manual mode and varies the aperture in combination with the shutter speed when the camera is used in Program Shift mode.
• Exposure Compensation Set: decides the way exposure compensation is performed when the flash is used;
  • Ambient and Flash: varies the aperture, shutter speed and amount of flash light produced.
  • Ambient Only: only varies the shutter speed and aperture, the flash output being fixed.
• AF Illuminator: On or Off. Decides whether or not the AF assist light is used when there is insufficient ambient light for the autofocus to operate reliably.

• Shutter Lock: decides whether or not the shutter can be released when there is no memory card in the camera.
• Shutter Lock: decides whether or not the shutter can be released when there is no lens mounted on the camera.
• AF Area Setup: decides the length of time the active AF point is lit-up in the viewfinder (0.3, 0.6 second or Off).
• Monitor Display: decides whether or not the proximity sensor located under the viewfinder turns off the LCD screen when it detects the user near the viewfinder.

• Rec. Display: decides whether or not the information display on the monitor rotates with the camera when it is held in portrait/vertically, or landscape/horizontally.
• Play. Display: decides whether images are played back with the same orientation as they were captured (landscape or portrait).

The Alpha 100 is equipped with a CompactFlash type I & II slot that is compatible with microdrives. The Alpha is supplied with a CF/Memory Stick Duo (AD-MSCF1) adapter so it can it be used with the Sony's own memory format. The card slot is located on the right side of the camera, behind a solid door that must be slid back first so it can be opened. The same compartment also contains a dual use connection, depending on the cable used, the USB Port (2.0 High Speed) or the Video Out connection (NTSC or PAL).

The chart below indicates the number of images that can be captured using an optional 2 GB CF card:

The Alpha 100 is powered by a rechargeable Lithium-Ion battery (NP-FM55H), which is housed in the grip and covered by a latching door. A charger (BC-VM10) is supplied along with the camera, and it requires approximately 4 hours to fully recharge a depleted battery.

Another jack is located on the lower left side of the camera. It allows connecting the camera to an optional AC adapter (AC-VQ900AM), which can also recharge two batteries simultaneously.