by Bob Atkins, May 2008
photography by Bob Atkins and Hannah Thiem
The Sony Alpha A700 is Sonys mid-leveldigital SLR, competing in the same price class as the Canon EOS 40D, the Pentax K20D and the Nikon D200/300. In theSony line (formally the Konica/Minolta line) of DSLRs the Alpha A700is probably closest to an evolution of the Minolta 7D. It was first released in September 2007.
The Sony Alpha A700 is compatible with all A-mount Minolta SLR andDSLR autofocus lenses and accessories. Note that the Sony A700 cannotaccept Minolta MD-mount manual focus lenses.
Though it doesnt directly address Sony cameras, newcomers to theworld of DSLRs might want to start with the photo.net article "Buildinga DSLR System".
The Sony A700 isavailable in various packages from amazon.com:
Unlike its direct competitors, the Sony A700 lacks a dedicated LCDfor displaying camera settings. The large rear LCD is used for bothimage and data display. This results in a simpler user interfacebecause there is only one place on the camera to look forinformation. However, the rear LCD can be quite difficult to see in brightsunlight, just the opposite of the typical top mounted B&W reflection typeLCD displays. Personally Id rather have a top LCD with the option ofalso displaying capturing information on the rear LCD, as is possiblewith the Canon EOS 40D.
There is just one main control dial on the left side of the top ofthe camera and it controls the operating modes: Program, Aperturepriority, Shutter priority and Manual plus multiple scene modes(Auto/Green, Portrait, Landscape, Macro, Sports, Sunset and NightPortrait). On the right side of the top are dedicated buttons forsetting exposure compensation, white balance, ISO and drive mode.
The A700 has a conventional shutter release layout withthe main control dial being a vertically mounted wheel just in frontof the shutter release button used to set parameters such as shutterspeed and aperture. Theres a second control dial, which ishorizontally mounted at the top right of the rear of the camera. Thisserves essentially the same function as the Canon EOS rear QCD (quickcontrol dial), allowing the main control wheel to be adjusted usingthe index finger and the secondary control wheel to be adjusted withthe thumb.
On the back of the camera is the 3" LCD used for both imageand data display. As you can see from the above image, the orientationof the display text changes when the camera is turned from landscape toportrait mode. To the right of the LCD is the main four-waycontroller with a center button, which can be used to select menuoptions or navigate within an image. At the bottom right is the switchto select "Super SteadyShot" mode, Sonys sensor-based imagestabilizer. To the left of the LCD are the controls for displaying themenu, selecting which data are displayed, erasing images and recallingstored images. There are also dedicated buttons for exposurecompensation (+/-) and Auto Exposure Lock (AEL).
The LCD itself provides a high quality image. It has 922,000pixels, which corresponds to 640x480 resolution with RGB pixels ateach location. This is a similar specification to the LCD found onthe Nikon D300 (review), but provides abetter and more detailed image than the 230,000 pixel LCD of theCanon EOS 40D (review).
In addition to the pre-defined function buttons there is alsoa "C" (custom) button, which can be assigned to one of many functionssuch as DOF preview, AF/MF selection, image quality, ISO setting,drive mode, AF lock, etc.
Like the Minolta 7D, on which Im sure the Alpha700 is based, the A700 uses switches for functions which many othercameras control via buttons and menus. The metering pattern is setusing a 3-way switch on the back of the camera to select among spotmetering, center-weighted metering and multi-segment metering. AF modecan be set by a 4-way switch on the front of the camera just below thelens. The options there are "S" - single (one shot) focus, "A" - Auto(switches from one shot to continuous, depending on subject movement),"C" - continuous (tracking) and "M" - manual focus. Whether you preferbuttons or switches is a personal choice. Im sure you can getused to either approach.
Note: All timing measurements were made using a Sony 300x CFcard.
The Sony Alpha A700 takes about 1 second to "bootup". After that the camera is pretty responsive and it wakes up from"sleep" mode almost instantly. After a shot is taken, the imageappears on the LCD screen in about 1 second.
In continuous drive mode with the shutter speed set to 1/500s, ISO setto 200 and saving images as Large/Fine JPEGs, I measured a burst rateof 4.92 frames/sec. I couldnt fill the buffer to the point where thecamera slowed down, and I gave up after 200 frames! Saving the imagesin RAW mode the burst speed was 4.9 frames/sec for 18 frames, then therate slowed to 2.1 frames/sec
These are pretty impressive numbers, especially if yourephotographing JPEGs. As long as you have a fast memory card you reallydont have to worry about filling the buffer. When capturing RAW youcan fill the buffer after about 18 images, but even then the A700 willcontinue at over 2 fps for as long as you hold the shutter releasedown.
The Sony A700 uses 11 autofocus zones. The center zone has a cross-typesensor, responsive to both vertical and horizontal detail, while theremaining 10 zones are line-type sensors, which respond to detail onlyin one orientation. A sensor detects when an eye is placed against theviewfinder and starts auto focus. With this function enabled, by thetime you get the camera to your eye, the AF system may already haveacquired focus. With eye-start focus off, AF is initiated with a halfwaypress of the shutter release.
Auto focus seemed fast and positive, with very little focus huntingin good light. I did see some problems getting focus in low lightusing the Sony 70-300/3.5-5.6 lens in low light where there would beoccasional focus uncertainty before final lock, but that may be moredue to the lens than the camera.
Auto white balance (WB) performed well in outdoor lighting, but likemost other DSLRs didnt so so well indoors under tungsten andfluorescent lighting where results were quite warm. Using tungstenand fluorescent settings improved matters, but images were stillslightly warm. As usual, if you want accurate color balance, the bestoption is to manually select the color temperature or use the customwhite balance feature.
The WB modes available are: Auto, Daylight, Shade,Cloudy, Tungsten, Fluorescent, Flash, Color temperature (2500 K to 9900 K) and Custom.
The viewfinder isquite bright and uses a glass pentaprism (some cheaper cameras use apentamirror system). Viewfinder magnification is 0.9x and viewfindercoverage is 95 percent, which is about average for this class ofDSLR. There is a -3 to +1 dioptric adjustment.
The in-viewfinder LCD display is presented just below the image. Itshows the usual information: flash exposure compensation, flash mode andreadiness, focus confirmation, shutter speed and aperture, exposurecompensation and/or metering, and the number of images that can bestored in the cameras buffer memory. In addition, thedisplay shows an indication of camera shake and the abilityof the anti-shake system to compensate for it via a multi-bar graph(rather like the signal strength indicator on a cell phone).
The Sony A700 has built-in "Super SteadyShot" imagestabilization. Sensors in the camera detect motion and move thedigital imaging CMOS sensor so as to compensate. This method ofstabilization was pioneered by Minolta in the Maxxum 7D and a similarin-body stabilization scheme is used by both Pentax and Olympus.
There is some debate about the relative effectiveness of sensor-basedstabilization vs. Nikon and Canons lens-based stabilization. To getsome idea of their relative performance, I tested the Sony A700 with a70-300mm zoom set to 300mm and a Canon EOS 40D with an EF 70-300 IS lensalso set to 300mm. I obtained a number of images with each camera atshutter speeds from 1/500s to 1/25s. The standard rule of thumb is thata photographer should be able to handhold a 300mm lens on thesecameras at shutter speeds of 1/500s and faster and get sharpimages. At lower speeds your chance of sharp images should dropsignificantly. Photographing at 1/250s is 1 stop slower, 1/125s is 2stops slower, 1/60s is 3 stops slower and 1/30s is 4 stops slower.
The results showed that the effectiveness of the Sony Super SteadyShotsystem seemed pretty similar to that of the Canon lens-basedstabilization system. Giving numerical results is difficult becausephotographs can range anywhere from sharp to blurred - and all degreesof sharpness in between. At 300mm, most of the images taken at 1/160swere acceptably sharp. At 1/80s about 40% were acceptablysharp. Thats about 2-2.5 stops of stabilization. With the Canon lensat 300mm the probability of sharp images at 1/80s was a little higherand Id estimate the stabilization at maybe 2.5-3 stops.
Whatever the relative merits of the two stabilization systems, itsclear that the body-based Sony Super SteadyShot has the advantage ofstabilizing all lenses mounted on the A700 body. Additionally you only pay for stabilization once because it is built into thebody. Also, if you buy a new body with an improved stabilizationsystem, the improved stabilization is realized with every lens. If anew lens stabilization system is developed, you have to replace allyour lenses to take advantage of it, which is a much more expensiveand less attractive proposition.
Remember that any image stabilization system, whether based on thelens or the camera body, stabilizes camera motion not subject motion.If your subject is moving, e.g., at a sporting event, you need a fastlens (f/1.4, f/2, or f/2.8) and/or a high ISO setting in order to keepthe exposure time short enough that the image isnt blurred by subjectmotion.
The Sony Alpha A700 has a 12MP sensor, 2MP more than that used inthe Canon EOS 40D and the Nikon D80. Does this significantly increaseresolution (and hence sharpness)? Well, in theory 20% more pixelsmeans that the linear resolution should increase by about 10%. Thisshould be measurable, but not really noticeable except if printingvery large images.
Above are 100% crops fromthe center of a Sony Alpha A700 12MP image and a Canon EOS 40D 10MPimage. They were taken with different lenses, but both werephotographed at 100mm and f8, which is a setting that should be prettysharp with any lens. At this scale, these crops represent a sectionfrom a 24x36" when viewed on a typical 17" monitor at a screenresolution of 1280x1024. As you can see, the A700 crop has slightlybetter resolution of the "2.5" line set, but the difference betweenthe images is small.
The Sony A700 uses a 12MP CMOS sensor with an ISO range from100 to 6400. Unlike some of its competitors, the Alpha A700does not have an ISO display in the viewfinder, something I findquite useful on my EOS 40D. The Pentax K20D, Nikon D200/D300 and EOS40D all have viewfinder display of ISO setting, though the Nikon D80does not.
Noise levels are pretty well controlled up to ISO 400,with noise becoming more visible at higher ISO settings. The imagesbelow are 100 percent crops from images captured at ISO settings from100 to 6400 with the Sony A700 and from ISO 100 to ISO 3200 with theCanon EOS 40D.
As you can see, the noise level of the Sony A700 looks a littlesmoother than that of the EOS 40D, but that appears to be due tosomewhat more aggressive noise reduction. In other tests, the EOS 40Dimages tended to hold onto more detail at ISO 3200 at the expense ofsomewhat more visible noise. This test (a gray card at 100 percentcropping) is designed to reveal noise. In a typical image printed at8x12, both cameras would be fine up to ISO 800, with noise creeping inat higher ISO settings.
When ISO is set to 1600 or higher, noise reduction isautomatically applied. The default setting for high ISO noisereduction is "normal", but "low" and "high" settings can be used. Inpractice there isnt very much difference between the threesettings. The A700 seems to apply noise reduction to RAW files, whichis in contrast to most other DSLRs. This may be due to the sensordesign, which includes hardware noise reduction and A/D conversion onthe digital sensor chip itself, rather than having those functionsapplied in separate steps.
Dynamic range optimization (DRO) is designed to recover details indark or bright areas of the image. The Alpha A700 has three DROmodes: Standard mode, Advanced mode and Advanced Bracketing mode.Standard mode attempts to improve shadow detail using standard gammacurves. In Advanced mode you can select auto or one of 5 manual DROcorrection levels and in Advanced Bracketing mode, you canautomatically take three photos at different DRO levels with a singleshutter press.
DRO does seem to work, though the Advanced manual modes seem a lotmore effective at raising the level of dark shadow areas than eitherthe standard or advanced auto modes. Bringing up the shadowlevels tends to increase shadow noise, but thats often areasonable trade-off. DRO does not affect RAW files, so presumably itsa software function which changes the shape of the tone curve.You can also vary the DRO level when converting RAW files, which alsosuggests that its done entirely in software.
Maximum shutter speed for syncing with flash is 1/250s or 1/200swith Super SteadyShot enabled. The built-in flash, which must bemanually raised and lowered, has a useful range of about 10 ft. (guidenumber of 12 in meters at ISO 100; higher ISO settings result inlonger flash range). The built-in flash has to be manually raised.The flash covers the field of view of a 16mm lens (equivalent to thatof a 24mm lens on a full frame camera).
There are seven flash modes: Automatic, Fill, Red-eye reduction, Rearsync, Wireless, High-speed sync, and Slow sync. In wireless mode thebuilt-in flash sends a series of optical pulses to an external flashsuch as the Sony HVL-F56AM Flash, (buy from Amazon). The external flashfirst fires a metering pre-flash, which the camera uses to setexposure. The built-in flash then sends a second series of pulses,which tell the external flash how much power to use. Contrast thiswith the Canon system, which requires a hot shoe flash such as the580EX II in order to fire and control a wireless slave such as the430EX. Using the built-in flash as a wireless flash controller is a simpler and less expensive solution.
The Sony system currently offers several external flash units, theSony HVL-F36AM Flash, (buy from Amazon), the more powerfulSony HVL-F56AM Flash, (buy from Amazon), and the Sony HVL-MT24AM Macro Twin Flash,$499.
The A700 has a card slot for Type I or II Compact Flash (CF)memory cards and for Memory Stick Duo cards. You can store images oneither type of card, but you cannot write to both cardssimultaneously. The Memory Stick card format was developed by Sonyabout 10 years ago (1998) but it hasnt really caught on as a majorplayer in the flash memory market. The capability to use Memory Sticksmay be useful to those upgrading from earlier Sony cameras who alreadyhave a supply of Memory Stick cards, but I think that most users willchose the more widely available, less expensive and higher performanceCompact Flash memory.
The A700 uses a NP-FM500H Li-Ion rechargeable battery witha rated capacity of 1650 mAh. Sony specifications indicate that youshould get around 650 captures on a single charge in average use. Abattery charger is included with the camera and an optional AC adapteris available.
A vertical grip, the VG-C70M, is available for the Sony AlphaA700. As well as offering a shutter release convenient for verticaloperation, the VG-C70M has two control dials, function buttons and canaccept two battery packs for extended capture time.
The A700 is constructed of a high strength aluminum chassis with amagnesium alloy body shell and a plastic covering. The grip section ofthe body has a textured rubber covering to make it a little easier tohold.
The control ergonomics are good and its possible (though perhapsnot advisable) to operate most of the more commonly used cameracontrols one-handed.
The A700 is slightly larger (141.7x104.8x79.7mm vs. 133x95x71mm)and slightly heavier (768g vs. 638g inc. battery) than the A100, butit should be much more durable.
The Sony Alpha A100 can use any of the Sony or Konica-Minoltaautofocus lenses. They range from theSony 11-18mm f/4.5-5.6 DT andSony 16mm f/2.8 Fisheye to theSony 300mm f/2.8 and theSony 500 f/8 AF Reflex mirror lens. Tokina,Tamron and Sigma also make lenses that are compatible with the A700.
The following Sony lenses have been reviewed on photo.net:
Like all Sony DSLRs, the Alpha A700 is compatible with all Minoltaautofocus lenses. but it is not compatible with any earlier Minolta MDmount (manual focus) lenses.
Adapters are available, which allow the mounting of Minolta MDlenses on the Sony A700, but they contain optics (to enable infinityfocus) which increase the focal length slightly, reduce the maximumaperture slightly, and almost certainly lower the image quality. Whenusing such adapters manual focus must be used and the lens must bemanually stopped down.
A PDF copy of the User manual (and other A700 documentation) canbe downloaded directly from the Sonyweb site.
The Sony Alpha A700 is competitive in terms of price, performance andfeatures with cameras such as the Canon EOS 40D, (buy from Amazon) (review),Pentax K20D, (buy from Amazon) (review), and the Nikon D80, (buy from Amazon) (review).The Sony system of lenses and accessories is smaller than Pentaxs andmuch smaller than Canons and Nikons. The A700s main advantage oversimilar priced bodies from Canon and Nikon is the built-in imagestabilization, though the Pentax K20D not only has body basedstabilization and extensive weatherproofing, but also has a 14MPsensor, 2MP more than the Sony Alpha A700 and Nikon D300.
One feature that the Sony Alpha A700 lacks which is present onmost new DSLRs is a "LiveView" mode. The Canon EOS 40D, the NikonD300, and the Pentax K20D all have LiveView capability, though theNikon D80 doesnt.
For anyone with an investment in Minolta/Sony AF lenses, the SonyAlpha A700 is a logical upgrade and currently Sonys most professionaland full featured DSLR. Its clearly a very capable camera offeringhigh image quality, fast operation and (in JPEG mode) the ability tocapture 5 fps bursts of hundreds of images when a fast CF card isused.
Those without a prior investment in lenses would need to carefullyweigh the various DSLRs systems offered by Nikon, Canon, Pentax andOlympus to see which best meets their needs. With a maturingtechnology, DSLRs at this level are all capable of yielding excellentresults. Each system offers some unique features or lenses and buyershave to decide which factors are most important to them.
Amazon.com offers the Sony Alpha A700, (buy from Amazon).To make it a complete package, consider the lens recommendations aboveunder Choosing aLens, and you may want to add one or more SanDisk 8GB, 4GB, or 2GB CF cards.
Sony 75-300mm f/4.5-5.6,set at 230mm, 1/640s, f/5.6, ISO 200, multi-segment metering.Even though the edges of the images may get a little soft with this lensat 230mm, in many situations (such as this one), the center of the imageis much more important than the edges (which will be out of focus anyway)
Sony 75-300mm f/4.5-5.6, set at 160mm, f/5.6,1/40s, ISO 400, multi-segment metering, manual exposure mode. Althoughthis decorative light fixture was photographed against a luminescentwindow, the A700 did a great job with the colors, sharpness. I usedthe AE Lock button to focus on the colored object before recomposingthe image.
Sony 75-300mm f/4.5-5.6, set at 75mm, f/4.5,1/40s, ISO 200, multi-segment metering, manual exposure mode. Althoughhandheld at 1/40s, the image stabilization helped me capture this. Iwanted the least amount of noise in this photo, hence the ISO settingand a slower shutter speed.
Sony 70-300 f/4-5.6 G SSM, set at 75mm,1/250s, f/5.6, ISO 400, multi-segment metering. At 75mm the imagesharpness is quite good across the frame.
Sony 100mm f/2.8 Macro, f/2.8, 1/500s, ISO640, multi-segment metering. The edges of the photo are out of focus,but this is probably more due to the angle of view and how close I wasto the subject.
Sony 70-300 f/4-5.6 G SSM, set at 75mm,1/100s, f/5.6, ISO 400, multi-segment metering. Though the sky isbright and the foreground dull, the A700 has just avoidedoverexposing the sky (average level around 252, where 255 isfeatureless white).
Text ©2008 Bob Atkins; Images ©2008 Bob Atkins or Hannah Thiem.
Article created May 2008