Sony Alpha A100

Review
Sony Alpha A100
Introduction

The Sony Alpha A100 was the first 10 megapixels digital SLR to sell below $1000 USD. Brought to market by Sony using a sensor first seen on the Nikon D200 and a legacy of technology and optics acquired from Konica-Minolta, the launch of the Alpha A100 generated high-expectations. Months later, the Sony A100 faces many tough competitors: the Canon Rebel XTi, the Nikon D40X, the Nikon D80, the Pentax K10D, the Olympus E-410 and the Olympus E-510. Although several 10 megapixels DSLR cameras have been announced since, our 10 Megapixels DSLR Comparison feature compares the currently-available contenders in terms of features and specifications.

As expected from a modern DSLR, the Sony Alpha A100 is a full-featured digital camera with full-manual controls, custom white-balance, high-ISO, a wide range of shutter-speeds including a bulb mode, exposure-compensation, interchangeable lenses, continuous drive, an optical viewfinder and a large LCD. Having gotten awards and top-marks from over 10 professional review web sites, it is widely known that this is an excellent camera. However, a quick look at reviews of competing DSLRs reveals that they too are mostly excellent digital cameras. With that in mind, Neocamera takes an in-depth look at what is special and distinctive about the Sony Alpha A100.


Sony Alpha

The most important feature of this DSLR is its built-in stabilization. Built-in stabilization can bring both unequaled flexibility and cost savings. There are many types of lenses which do not have any stabilized counterparts, in particular, prime lenses and most bright zooms. This means that photography is possible in darker conditions than without built-in stabilization. The cost saving aspect can also be very important as it saves up to $500 USD per lens. It can also make a standard zoom usable when a bright and more expensive zoom would normally be required. Note that this feature is no longer unique to this 10 megapixels DSLR since it is also found on the Pentax K10D. The recently announced Olympus E-510 will also feature a similar mechanism. Another important feature of the Sony Alpha A100 is its built-in dust-reduction system. At the time of its launch, the Alpha A100 was the only non-Olympus DSLR that sported such system. Since then, everyone but Nikon has implemented this feature.


Even though it is the oldest affordable 10 megapixels DSLR, the Sony Alpha A100 still has several unique features: a Dynamic-Range-Optimizer (DRO), dedicated low-key and high-key sensitivities and an eye-start sensor for initiating auto focus. An in-depth discussion of these unique features is included further in this review. As for its more-standard feature set, here it is:

* 10 Megapixels image sensor, 1.5X crop-factor.
* Minolta A-mount, supports nearly all AF Konica-Minolta lenses.
* ISO 100 to 1600, Auto ISO (100-400), Low-key ISO 80 and High-key ISO 200.
* 1/4000s to 30s shutter-speeds, plus bulb mode.
* Metering modes: multi-segment, center-weighed and spot.
* Exposure compensation: -2..+2, 1/3 EV inc.
* Flash compensation: -2..+2, 1/3 EV inc.
* Exposure bracketing, 3 images, 0.3 or 0.7 EV inc.
* Automatic white-balance.
* Preset, Kelvin and custom white-balance, all fine-tunable along green-to-magenta scale.
* 9-point auto-focus system.
* Focus-point selection: automatic, manual or center.
* Focus modes: single-shot, direct-manual (DMF), continuous, auto-switching and manual.
* Full manual controls.
* Unlimited 3 FPS continuous drive.
* 10-second and 2-second self-timers with automatic mirror-lockup.
* Dedicated Auto-Exposure-Lock (AEL) and optional Auto-Focus-Lock (AFL).
* Customizable saturation, sharpness and contrast, 5 steps.
* 2.5" LCD 230K Pixels with automatic rotation of status screen.
* Eye-start sensor automatically controls LCD and optionally starts auto focus.
* 0.83X Magnification viewfinder, 95% coverage.
* Image review with magnification and histogram.
* Depth-of-field preview.
* JPEG and RAW modes.
* Built-in flash.
* Lithium-ion battery.
* Compact flash memory.

Suitability - What is it good for?

Since DSLR cameras represent the high-end of digital cameras, they are generally suitable for most types of photography. The versatility of interchangeable lenses gives SLR cameras their greatest potential. The Sony Alpha A100 is no exception, it is suitable for every type of photographic subject.

Lens group

The introduction of 19 lenses along with the Alpha A100 helps keep it versatile. Among these lenses are several highly desirable - and expensive - ones by Carl-Zeiss. Sony sells the A100 alone, with a 18-70mm F3.5-5.6, with a 18-200 F3.5-5.6 or with a 18-70mm F3.5-5.6 and a 75-300 F4.5-5.6. These are all medium quality lenses with typical narrow apertures. The most unique lens among Sony's lineup is the Carl-Zeiss 16-80mm F3.5-4.5 which is equivalent to 24-120mm in 35mm terms. What is special about it is that there are very little zooms which start this wide and none with a 5X or more zoom range. Another high-quality lens from Sony is the ultra-wide 11-18mm F4.5-5.6 which shows excellent sharpness and very little distortion for such focal-length. Several of our image samples were taken with that lens. Numerous lenses are also available from third-party companies such as Sigma. Most out-of-production Konica-Minolta auto focus lenses are also compatible with the A100.

Feature-wise, a few DSLR cameras are better suited for action-photography. Even though the Alpha A100 can shoot at 3 FPS indefinitely, some cameras can shoot faster. Specifically, the 8 megapixels Canon EOS 30D and the 10 megapixels Nikon D200 both shoot continuously at up to 5 FPS. Like all forms of stabilization, Sony's built-in stabilization only compensates for the photographer's movements, never the subject's. In other words, it does not effectively help for action photography.

The Alpha A100 is nor the largest nor the smallest 10 megapixels DSLR. In terms of weight, its also near the middle of its class. Given its size and weight, the Sony A100 has a solid feel without being tiresome to carry. It is certainly no more noticeable than most consumer-oriented DSLR cameras.

Sony Alpha Steady Shot


Capability – What can it do?

As noted in the introduction, the Sony Alpha A100 has everything expected from a DSLR plus a few unique features. Headline features include built-in stabilization, renamed Super-Steady-Shot from Konica-Minolta's Anti-Shake, an eye-start sensor, also inherited from Konica-Minolta, a dust-reduction mechanism, an unlimited 3 FPS continuous drive and a unique dynamic-range-optimizer, called DRO.

The camera's only LCD has multiple duties: playing back images, changing camera settings and displaying status information. In shooting mode, the LCD displays the camera status until it is cleverly deactivated by the eye-start sensor situated under the optical viewfinder. As soon as your eye, or any other object, gets near the viewfinder, the LCD is immediately turned off. This no-user-intervention approach is great because it does exactly what needs to be done smoothly. This saves power and prevents the LCD from interfering with the viewfinder's normal use. Using the LCD as a status display makes it easier to check the camera's status between hand-held shots than with a top mounted LCD. However, when using a tripod below eye-level, a top-mounted LCD would be preferable. Another neat trick with the status display is that it automatically rotates with the camera for improved readability.

The eye-start sensor also optionally serves to start the focusing system. This is designed to shorten the time to lock focus by letting the camera start focusing before the shutter-release is half-pressed. How useful this is depends on your shooting style: If you keep your eye to the viewfinder for a while before taking a shot, focus lag can be greatly reduced; If you hang the camera from your neck between shots, you may be annoyed at hearing the camera continuously focus. Either way, this feature can be deactivated in the setup menu.

Sony Alpha A100

Among several features taken from the Konica-Minolta Maxxum 5D the Sony Alpha A100 offers high-key and low-key modes. In addition to Automatic, 100, 200, 400, 800 and 1600, the ISO can be set to Lo80 or Hi200. These two last settings set the camera's ISO and the tone-curve used to produce JPEG images from the sensor's RAW data. The Lo80 mode is designed to photograph dark subjects while retaining a significant amount of shadow-details. This is done by ensuring that the ISO is very low so that noise does not interfere with shadow-detail and by allocating more brightness levels than normal to the shadow-areas. The Hi200 mode is designed to photograph bright subjects while retaining details in highlight areas. It works by slightly underexposing the image and spreading highlight-detail over a wider range of brightness levels.

Sony Alpha A100

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.

Sony Alpha A100

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.

Sony Alpha A100

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.

Sony Alpha viewfinder

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.

Sony Alpha function dial (Fn)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.

Sony Alpha 4-way controllerLike 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.

Performance - How well does it take pictures?

Ultimately, it is the image quality that makes a camera worth buying. For an SLR, image quality greatly depends on the lens used. While color, noise, exposure and contrast are properties of the camera, distortion, vignetting and chromatic aberrations are properties of the lens. Sharpness depends on the weakest link. That is, the camera cannot capture more detail than the lens lets through. Conversely, it is possible for a lens to transmit more detail than the sensor can capture.

Sony Alphe Hand Grip

Multi-segment metering of the A100 is rather good. Overall, metering is conservative and avoids burning highlights. Occasionally, this may produce images which are darker than expected, but it keeps more highlight details than the average DSLR camera. The default metering is extremely consistent, probably due to the 40-segments used to calculate exposure. It is important to remember that the A100 has several unique settings which affect exposure. Particularly, the DRO, Lo80 and Hi200 settings. Using those settings, the Alpha A100 can capture a greater dynamic range while retaining more shadow or highlight details. The first set of scaled images below illustrates the differences between the normal and keyed ISO settings. The second set of scaled images shows the effect of the three possible DRO settings.

The Sony Alpha A100 produces very accurate colors in standard mode and slightly over-saturated colors in vivid mode. The colors in vivid mode are excellent for prints, with pleasing color saturation. The white-balance system is good, and substantially better than any other Sony cameras we have seen. Outdoor white-balance is neutral under most conditions. Even snow was rendered as white most of the time. Indoors, white-balance is not as accurate. Incandescent lighting leaves a noticeable yellow cast when using automatic white-balance. Preset white-balance is much better, requiring only a little fine-tuning under artificial light. Note that most DSLR cameras suffer from his problem. Compared to the competition, the Sony Alpha A100's automatic white-balance is about average. Custom white-balance, on the other hand, is excellent and adapts well to unusual lighting. The custom white-balance function can also be used as a color-meter since it reports the sampled color-temperature.

Images taken between ISO 80 and 200 show very low noise levels. The Lo80 particularly is extremely smooth. Noise at ISO 200 is negligible and would not be visible unless printing beyond the resolution of the camera. At ISO 400, noise starts becoming noticeable, particularly in shadow areas. For bright scenes, an ISO 400 can be printed at 18"x12" without concern for noise. With dark scenes, ISO 400 noise is much more visible and prints beyond 8"x10" will show some graininess. This is where the A100's performance drops below average compared to other DSLRs in its class. Noise levels further increase at ISO 800 and 1600. The ISO 800 setting is quite usable for most scenes when printed at 8"x12" or smaller. At ISO 1600, only 4"x6" prints are certain to look smooth.

While the most important factor for image sharpness with a DSLR is the lens, the camera's internal processing affects the result. In the case of the Sony Alpha A100, sharpness is controllable in 5-steps. Each step results in a noticeable jump in image sharpness. The default is good and acceptably sharp. A single-step increase in sharpness improves images for display purposes. The maximum two-step increase produces a very sharp image with a somewhat artificial feel. Particularly, increasing sharpness makes image noise more visible. Relative to sensitivity, sharpness slowly diminishes as ISO increases past 400.

The overall image quality of this DSLR is good. At low ISO settings, including Lo80 and Hi200, the Sony Alpha A100 produces superb images, thus matching its best competitors in terms of color, noise and exposure. Starting at ISO 400, noise levels start falling behind but do not become a problem until ISO 800. The recommendation is therefore that this camera's image quality be considered ideal for photography at low ISO sensitivities.

Sony Alpha Steady ShotOne of the Sony Alpha A100's most outstanding features is its built-in stabilization. This feature proved to be very effective. Sony claims up to 3.5 stops of improvement over normal hand-holding. In practice, we consistently got at least a 2-stop advantage. A 3-stop advantage was also frequently possible but occasionally left some slight image blur. This stabilization advantage somewhat compensates for the image noise at high-ISO, although not for moving subjects.

The A100 is fast and responsive. Shot-to-shot lag is very short, as long as focus can lock fast enough. That depends on the lens and lighting conditions, but the focusing system is extremely accurate. This is where the eye-start focus works to the Alpha A100's advantage. By pre-focusing before the shutter-button is half-pressed, focus lock time is greatly reduced. Image playback and zoom are very fast, even when switching between images while being zoomed. In terms of speed, the A100 never lets the photographer wait. The continuous shooting at 3 FPS can continue until the memory card gets full. No similarly priced 10 megapixels DSLR can do better.

Conclusion

The Sony Alpha A100 may have competitors from every other DSLR maker, but it stands up to them well. It has the second most advanced feature-set, just behind the Pentax K10D, but it also packs several unique features. With good image quality, great ergonomics, effective stabilization and superb speed, the Sony Alpha A100 is hard to beat.

The Alpha A100 clearly shows a well thought-out feature set and innovative features aimed to help the photographer. Particularly the low-key (Lo80) and high-key (Hi200) settings are very useful when dealing with high-contrast subjects without any post processing. The DRO system can often help with high-constast subjects too but since its result is less predictable, it is preferable to use this feature for shots which can be re-taken. For action shots, it is better not risk the DRO doing the wrong thing. This unpredictability would have been a non-issue if Sony had provided a virtual bracket for DRO as it did for white-balance.

Another superb aspect of this DSLR is its ergonomics. The camera is easy to hold with well-placed buttons to control important functions. The LCD, which serves as a status screen and is controlled by the eye-start sensor, greatly contributes to the overall ergonomics. Although there are a few things missing (such as a second control-wheel, to make this into pro-ergonomics), the A100's handling is among the best in its class.

The only disappointing aspect of the A100's performance is its high-ISO performance. ISO 800 and up should be avoided for photographs which may end-up printed big. For small prints, it is not a serious issue. In terms of low-light photography, the Sony Alpha A100 does quite well thanks to its built-in stabilization. It is low-light action that is the problem, particularly indoor sports where fast movement requires high ISO settings.

The bottom line is that the Sony Alpha A100 brings many unique features and produces high quality images under most conditions. Unless high-ISO is required for large prints, this is one of the best DSLRs to choose. Considering it has built-in stabilization and is priced relatively low, the A100 is an excellent value. Its closest competitor, the weatherproof Pentax K10D, is worth a look for its own unique features. Another interesting competitor is the Canon Digital Rebel XTi. It performs better at high-ISO but lacks stabilization and is not as ergonomic. For action photography, particularly indoors, the 8 megapixels Canon EOS 30D or the much more expensive Nikon D200 should be considered for their 5 FPS continuous drive and high-speed focusing.

Wish List

No camera is perfect, this one included. Then again, there is always the next model. At PMA 2007, Sony announced a new model scheduled to come out before the end of this year. Here we list our top enhancement wishes for the next Alpha model. Actually, the last 3 options could probably be implemented in a firmware update.

* Lower image noise at ISO 800 and above.

* Add a second control-wheel for faster changes in manual mode. Also, let it control ISO or exposure compensation in semiautomatic mode. It could also be used for zooming during playback.

* Add an ISO dial or dedicated ISO button. This would allow changing ISO without leaving the viewfinder. It would be nice if the ISO setting remained visible in the viewfinder at all times.

* Provide a usable ISO 3200 (or higher) option.

* Make the viewfinder have 100% coverage.

* Add a setup option to reset some settings on power-off. The most likely candidates are EC, WB, drive-mode, metering and ISO. They should be individually selectable.

* Make the simple vs. detailed status screen a setup option, that way the display button becomes an on/off switch. Since the detailed status screen is a superset of the other, users are expected to use one only.

* Add a DRO virtual bracket option. This would take one picture but save it 3 times, once with each DRO setting applied.

Lastly, adding support for a standard losslessly compressed high bit-depth image file format such as 16-bit per channel PNG would benefit all DSLR cameras including this one. However, the Sony Alpha A100's DRO would particularly benefit from the added precision.

base

Overall Score:

Excellent

Unanimously Excellent

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