| 24.60
Megapixels | Sony Alpha (Minolta A) mount | 3.0 inch
LCD |
|---|---|---|
 | ||
 |  |  |  |  |
|
Basic Specifications | |
|---|---|
| Resolution: | 24.60 Megapixels |
| Kit Lens: | n/a
|
| Viewfinder: | Optical |
| LCD Size: | 3.0 inch |
| ISO: | 100-6400 |
| Shutter: | 30-1/8000 |
| Max Aperture: | n/a |
| Mem Type: | CF1 / CF2 / MS Duo / MS PRO Duo / Microdrive |
| Battery: | Custom LiIon |
| Dimensions: | 6.2 x 4.6 x 3.2 in.
(156 x 117 x 82 mm) |
| Weight: | 30.0 oz (850 g) |
| MSRP: | $2,000 |
| Availability: | 10/2009 |
|
Test Summary (Mouse over items for explanations) | |
|---|---|
| Power-on Time | 0.5 sec |
| Shutter Lag,
Full Autofocus | 0.184 sec |
| Shutter Lag,
Prefocused | 0.074 sec |
| Shot to Shot time | 0.40 sec |
| Continuous Speed | 3.00 fps
(23 shots) |
| Viewfinder accuracy
(Optical) | 98% |
| Battery Life
(CIPA standard) | 880 shots |
Sony A850 Overview
When it was first announced in September of 2008, the Sony A900 broke new ground in affordability for a full-frame DSLR. Since then, the competition has sharpened, with Canon's EOS-5D Mark II forcing an even lower price point. Now, slightly less than a year after the A900's announcement, the Sony A850 once rewrites the rules again, as the first-ever full-frame digital SLR with a list price of less than $2,000. While it's "only" $700 less than the current price of the A900, this is truly a landmark price point for a full-frame camera, let alone one with 24.6 megapixels of resolution.
Perhaps the most intriguing aspect of the Sony A850 is just how close it is to the A900 (which will remain in the market) in specs and behavior, at a price that's roughly 26% lower. Here's the very short list of differences:
| Sony A850 differences vs A900 |
|---|
|
That's it! Sony tells us that the body, sensor, and electronics are identical to those of the A900, and our tests of the Sony A850 bear that out: Image quality is essentially identical to that of the A900, and other performance characteristics apart from the continuous-mode speed and viewfinder coverage appear identical as well. If you've been hungering for an A900 but couldn't quite justify the cost, the Sony A850 is the camera you've been waiting for. And if you've been wanting to get into full-frame digital photography but couldn't previously afford it, this might finally be your opportunity.
Because the body, user interface, sensor, and electronics of the Sony A850 are the same as the A900, the bulk of our verbiage in this review is lifted straight from our review of the A900 last year. We did completely redo our image analysis and performance measurements, though, because we never simply take a company's word for it that a camera or part of a camera is "identical" to another: We always test to verify, and arrive at our own conclusions. In the case of the Sony A850, though, our tests supported the contention that it's the same image-wise as the A900.
So, if you're already well-familiar with our review of the A900, you can save yourself some reading here and make your decision whether or not to buy a Sony A850 based on price and the few differences from the A900's specs described above. On the other hand, if you're new to Sony's flagship DSLR cameras, read on: It's an impressive story.
As with the A900, the Sony Alpha A850 gets a whopping 24.6-megapixel resolution from its full-frame Exmor CMOS image sensor -- the highest sensor resolution of any 35mm digital SLR yet announced. To handle all the data produced by the high-resolution imager, the Sony DSLR-A850 uses dual Bionz image processors, allowing for three frames-per-second shooting for up to 23 JPEG or 16 RAW frames (in our tests).
The sensor is mounted on a moving platter that allows for in-camera image stabilization, branded as SteadyShot Inside. That's another world's first for a full-frame digital SLR, and it's no mean feat when you consider that the sensor shift mechanism has to deal with the extra mass of a full-frame sensor. The various digital SLR cameras seen to date that feature sensor-shift stabilization all have significantly smaller 1.5x crop sensors. Sony rose to the challenge by designing a new more powerful sensor shift mechanism, and rates the Alpha A850 as good for a 2.5 to 4-stop improvement.
Body. The Sony A850's body is magnesium alloy, with large openings for the LCD and lens mount, as well as a cutout for the card door. The battery grip is also magnesium alloy, as shown here. The overall feel is quite solid. The body is sealed against moisture, as are the buttons and dials.
The Sony A850's body is constructed from five main magnesium alloy sections, and includes sealing to reduce ingress of moisture between the body panels, as well as at the various control dials and buttons. The Sony A850 has a Sony Alpha lens mount that also accepts Konica and Konica Minolta glass. A large pentaprism sits above the lens mount, both dictating the camera body's workmanlike visual aesthetic, and providing a very large and bright TTL optical viewfinder with 0.74x magnification. The rear panel features a large 3-inch LCD display with 921,600 dot resolution, equating to VGA (640 x 480) pixel with three R, G, and B dots per pixel. This is used solely for reviewing of images, as well as for menus and status display; the Sony A850 doesn't offer live view capability. There's also a small top-panel status LCD which indicates remaining shots and battery life, as well as the basic exposure variables.
The Sony Alpha A850 offers ISO sensitivity from 200 to 3,200 equivalent, but is expandable to ISO 100 to 6,400 equivalent. Shutter speeds range from 30 to 1/8000 second, plus a bulb setting, and x-sync is 1/250 second (or 1/200 second when SteadyShot is enabled). Metering is achieved by a 40-segment honeycomb sensor, and you can also choose from center-weighted or spot metering modes. Focusing is achieved courtesy of a a nine-point phase detection autofocus system with f/2.8 dual center cross sensor, and there are also ten supplemental AF-assist points arranged adjacent to the main AF points. There's no built-in flash in the Sony A850, with the design instead offering a hot shoe and PC flash sync terminal to allow for external flash strobes and lighting setups.
The Sony A850 has dual flash card slots, and hence can store images on either CompactFlash Type-I or Type-II cards, or on Memory Stick Duo cards. The Sony A850 draws its power from a proprietary NP-FM500H InfoLithium rechargeable battery that's rated for about 880 shots per charge, to CIPA testing standards. Connectivity options include both USB 2.0 High Speed for computer connection, and both standard and high definition video. For standard-def, there's NTSC / PAL switchable composite video output, while high-def is achieved via an HDMI connection.
Sony A850 Pricing and Availability
Pricing for the Sony Alpha A850 is set at US$1,999.95, with availability slated for availability in the US beginning October 8, 2009. The product bundle includes the camera body, battery, and charger, and eyepiece cup. There's also a range of software in the bundle: Image Data Converter SR, Image Data Lightbox SR, Remote Camera Control, and Picture Motion Browser. This last application is Windows-only, while the remainder are included in both Windows and MacOS versions.
Sony A850 User Report
by Shawn Barnett and Dave Etchells
It takes but a glance to see that the Sony Alpha A850 is unique among modern digital SLR cameras. The large, pyramidal shape behind the SONY logo suggests that a very large pentaprism glass element lies underneath. A quick glance through the viewfinder completes the impression: it's like a room in there, into which it seems you might fall if you're not careful. 35mm camera owners from the last century will find the Sony A850's viewfinder comforting, then quickly forget about it and begin composing with an impressive photographic tool.
Like its most advanced sub-frame predecessor the Sony A700, the Sony Alpha A850 is big and boxy, not attempting to appear sleek, it looks more like a big industrial device, as cameras once did. Yet it fits well in the hand: a machine to the eye that is nevertheless well crafted for the human intended to use it.
Its weight is substantial, at 2.07 pounds (939g) without a lens, but with a battery and CF card (that's lighter than the Nikon D700 and just a little heavier than the Canon 5D Mark II); and it measures 6.1 x 4.6 x 3.2 inches (156 x 117 x 82mm). We mentioned the bulk and weight of the excellent Zeiss 24-70 f/2.8 zoom lens in our review of the A900; a natural companion to the A900/850, but one that came at a heavy price, both financially and in terms of weight. Simultaneous with the announcement of the A850, though, Sony also announced a new and very intriguing 28-75mm f/2.8 optic, with is not only substantially lighter (only 20 ounces/565g, vs. 33.3 ounces/955g), but sports a list price that's over a thousand dollars lower than the previous Zeiss optic.
The Sony A850's front panel looks a lot like that of the earlier A700, though the handgrip bulges a bit more into the hand, and the Mode dial is positioned straight and level, while the A700's was mounted at a slant. Missing from the front of the grip is the Grip-sensor that was part of the Eye-start AF system.
Just under the bright orange Alpha logo is the PC flash sync terminal, covered with a rubber flap. Like all other rubber flaps on the Sony A850, this terminal cover swings open and stays open, as it's hinged to the camera, rather than the rubber itself serving as a hinge. That means you don't have to fight with it as you make your connection.
The Sony A850's grip has a comfortable finger groove for the middle finger, in which the infrared Remote Commander sensor is nestled. The inside of the grip is indented for a better finger grip, as is the front of the camera between the grip and lens, which is fairly obvious in the photo above: a very nice touch that those with long fingers will appreciate. Textured rubber surrounds the grip areas both left and right of the lens. The bottom of the body on the left (on the right side in this image) is tapered to allow a more comfortable fit into your palm as you reach your fingers around to the lens barrel.
The rear of the Sony A850 is laid out identically to the Sony A700. Positions are slightly different, with the LCD taking up less of the overall space, mostly because there's more width overall. The left side tapers away just left of the LCD, somewhat minimizing the bulk of the bulge at the left, giving your nose a little break as well, as you move your right eye up to the viewfinder.
Shutter. Just left of the optical viewfinder, you can barely see a latch for the viewfinder shutter. Closing this when shooting on a tripod prevents light entering the eyepiece from affecting the exposure sensor.
The Sony A850's LCD is the same resolution as was on the A700, with 921,600 pixels, and a transflective (both transmissive and reflective) design, meaning that in bright daylight you can still frame images. Checking exposure accurately is a little harder, but that's what histograms are for. Note that though it's a hot feature on many of the latest digital SLRs, the Sony A850 has no live view mode; however, there is a new Intelligent Preview mode that can serve on occasion, and do a few tricks. More on that later.
Note that though there are still infrared sensors beneath the optical viewfinder, these are only for turning off the LCD when you put the camera up to your eye; Eye-start AF is no longer a feature on the Sony A850.
The rear Status display also opens up the option to change many settings right on the screen. Just press the Fn (function) button and use the joystick above it to navigate around the screen. Pressing down on the joystick activates your selection, which you can modify with one or the other control wheel (the rear or front wheel). It'll take a little time to figure out which wheel is necessary for each item, unfortunately. Some use only the front, others use both.
Here's the A900 with the big, beautiful Zeiss 24-70 f/2.8 zoom lens, a fitting if high-dollar mate to the Sony A850. We shot extensively with this lens, and found it to be better than satisfactory, worthy of the A850/900. It also balances out the camera's big body. See our review of this $1,800 lens on SLRgear.com. 
More intriguing for the A850 might be the new Sony SAM 28-75mm f/2.8 model (shown at right), which is smaller, significantly lighter, and over a thousand dollars less expensive. Watch SLRgear.com, we'll post a review of this new lens there as soon as we can get our hands on a sample!
Now's a good time to point out that there is no pop-up flash on the Sony A850, due partly to the very large pentaprism inside. I think many of the Sony A850's intermediate owners will miss the convenience of a pop-up flash, as an external flash unit significantly raises the weight of an already large and heavy camera.
The Mode dial on the left has only full Auto, Program, Aperture, Shutter, and Manual modes, plus three user-programmable Custom modes; there are no Scene modes. To the right there's a new top status display, one that's very simple compared to most high-end digital SLR cameras. It displays only numbers, usually the shutter speed and aperture values, along with remaining frames available.
Top buttons. Buttons for White balance and ISO are harder to reach with your hand on the grip.
The other four buttons on the top control Exposure Compensation, Drive mode, White balance, and ISO, working in concert with the rear control dial. While the front buttons for Exposure compensation and Drive mode are easy to press, we found the other two a little harder, comfortable with neither the thumb nor forefinger without removing your hand from the grip.
Quality port doors. Ports in clockwise order from the top left: Remote, HDMI, USB/Video out, and DC In.
The Sony A850's rubber doors are the best-behaved doors of this type that we've seen on any camera, swinging open and staying put, rather than flapping shut when you let them go. In clockwise order from the top left, they are Remote, HDMI, USB/Video out, and DC In.
Two card formats. CompactFlash and Memory Stick Duo slots.
Sony A850 owners will have the option of using CompactFlash (including Microdrives) or Sony Memory Stick Duo format. Unfortunately, switching between cards is not automatic when one fills up, as is common on other dual-card digital cameras; still, you can access it on the rear Status display, which turns into an onscreen menu when you press the Fn (Function) button.
Steady there, big boy. Though it's big, Sony managed to stabilize their 35.9 x 24mm, 24.6-megapixel imager. Click the icons in the lower left corner to see animation. Animation courtesy Sony Electronics.
SteadyShot INSIDE. Sony says many experts thought adding sensor-shift image stabilization to a full-frame digital SLR would be impossible, but they managed to get it done nevertheless. They're moving a very large sensor at high speeds, so it is quite an achievement. We haven't tested it in the SLRgear.com lab yet, but in casual shooting it seemed to work quite well. Sony states that it offers from 2.5 to 4 stops of exposure latitude.
Though all of us like seeing the stabilizing effects of Canon and Nikon's optical image stabilization through the viewfinder, we also like (very much) the five-bar meter that appears in the optical viewfinder to tell you just how much the SteadyShot system has to work. This lets you pick a moment to trip the shutter when the camera is the most stable, increasing your chances of getting a sharp shot.
The same mechanism activates at startup and shutdown to shake dust from the sensor, and a new anti-static coating has been applied to the outermost glass to reduce the amount of dust that can stick to the sensor. (Note that we've found most anti-dust systems to be only somewhat effective, and the lower shaking frequencies of IS actuator-based systems make them that much less effective than those using a piezo element to produce the vibration.)
Improved EV bracketing. Recent Sony digital SLR cameras were limited to only two automatic bracketing settings: +/- 0.3 EV or +/- 0.7 EV. The Sony A850 allows a full spread of EV options, up to +/- 2.0 EV, a more useful spread.
Interchangeable screens. The Sony A850 comes with a Type G focusing screen, but two additional screens are available: Type M and Type L. Type M, called Super Spherical Acute Matte is superior for discriminating between in-focus and out-of-focus objects, but unfortunately it dims the view somewhat, enough that it's only usable with lenses with maximum apertures of f/2.8 or more. Type L is the same as the very bright Type G, but with a grid for alignment or applying the rule of thirds. As with other digital SLRs that have interchangeable screens, the user has to set the type of screen in Settings menu 3.
Sensor. Sony's Exmor CMOS sensor is what gives the Sony A850 its magic. Above you can see how the A850's size compares to the Sony APS-C-sized sensor. Its pixels are actually larger than those in the Sony A700's 10-megapixel sensor, making for greater ISO sensitivity. The 24.6-megapixel sensor is more than just a sensor, however, as it includes the analog to digital (A/D) conversion circuitry right on board the chip. Over 6,000 A/D converters work in parallel to convert the image data before electronic noise can creep into the signal-processing chain. That makes for fast data acquisition too.
Processors. From there, the dual Bionz processors take the large files and crank them through fast enough to allow up to five frames per second capture, even in RAW + JPEG capture.
Power like that also allows for sophisticated functions like Peripheral Illumination correction, which fixes vignetting problems in many situations.
AF Sensor array. Blue points are the main AF points, oriented in the direction shown. The green blocks are the supplemental AF points.
AF system. The Sony A850 has the same new autofocus system that was introduced with the A900, with nine primary autofocus points and ten supplemental AF points. The user can select the nine AF points, but the ten additional points are used by the system to enhance the performance of the others when the Sony A850 is set to wide-area AF mode. A larger sensor in the center of the frame switches on when lenses of f/2.8 or larger are attached, allowing the system to take advantage of the larger aperture.
If you choose to use the Local AF mode, you can select from the nine AF points in the viewfinder with the joystick on the rear panel. Choose Wide, and the Sony A850 will choose for you. Choose Spot and the Sony A850 uses the more accurate center AF point. See the Optics section for a more detailed discussion of the Sony A850's AF system.
Lens compatibility. While the Sony A850 is compatible with the company's DT-series lenses, many of them, if not most, will vignette significantly with the full frame camera, since they were designed to deliver a smaller image circle to the company's APS-C format cameras. When a DT lens is mounted, the camera automatically captures an APS-C sized frame. Only four thin brackets inside the viewfinder indicate where the cropping will occur; it does not gray-out as seen on the Nikon D3. Incidentally, you can choose to shoot an APS-C sized image when a full-frame lens is mounted via an option on Settings menu 4. The image captured is 11 megapixels maximum in that mode. (Pretty amazing that you can crop the sensor that much and still have 11 megapixels to work with!)
Storage and battery. The Sony A850 uses CompactFlash (Type I and II as well as Microdrives) and MemoryStick Duo cards. The battery pack is the now-standard InfoLITHIUM NP-FM500H, a 7.2V 11.8Wh lithium-ion design, rated for 880 shots (same as the A900).
An optional battery grip is available for the Sony A850, the Sony VG-C90AM, which is light in weight, but increases the height of the overall camera to exceed the height of the Canon 1D-series and Nikon D3.
Still, the battery grip has a few interesting features, including the full array of buttons on the rear that duplicate the controls accessible by the right hand on the camera itself. The Sony Alpha system also uniquely has the unusual second shutter release location that is positioned slightly down from the right corner of the grip, which changes the balance dynamic of the camera. It puts the lens in the same plane with the shutter whether you shoot vertically or horizontally, and does distribute the weight more evenly in both hands if you keep the camera upright and use a lighter lens. The downside is that with a heavy lens, like the Sony 24-70mm f/2.8, most of that weight rests in your left hand.
Physical Comparisons
Sony A850/900 vs Canon EOS 1Ds Mark III
Pro configuration: If you're going to be shooting for long periods, a battery grip is a good idea, but it makes the A850/900 bigger than the comparable EOS 1Ds Mark III. Naturally, you don't have to use the battery grip to enjoy all the quality that the A850 offers.
Sony A850/900 vs Canon EOS 5D Mark II
Smaller full-frame: The Sony A850/900 is just slightly bigger and slightly heavier than the Canon EOS 5D Mark II. The Sony A900 beat the original Canon 5D handily in terms of resolution, but the competition is now close with the 5D Mark II. The 5D Mark II has the advantage of also recording HD video, albeit at a higher price, and minus the rugged injection-molded alloy frame and environmental sealing of the Sony A850/900.
Sony A850 vs Nikon D3x
David vs Goliath?: Here's the Sony A850 next to the Nikon D3x, this time without the optional battery grip that we showed on the A900 in the first comparison above. People have been waiting for/expecting a "D700x" from Nikon for a while now, packing the sensor from the D3x into a compact body, as was done with the the sensor from the original D3 and the subsequent D700. That hasn't happened as of this writing yet, so for now this is as close as you'll find to comparable resolution in the Nikon line.
Checking. Seeing whether you got the shot after capture is key, and of course the Sony A900's high-res 3-inch LCD really helps on that score. You always have to be careful with transflective displays, however, especially in sunlight. This can be complicated by using DRO modes, which, combined with the transflective display's metallic look, can make you think a shot is washed out more than it is. You can get used to this, and adjust accordingly, as I have, but checking the histogram is also a good habit, as is taking a few extra shots or shooting RAW when the work is critical.
Touching the Custom button (marked with a C) toggles on the Histogram screen, along with most of the exposure data. You get not just a luminance histogram, but red, green, and blue as well to help you gauge color casts.
You can zoom in by pressing the AF/MF button and turning the rear command dial. Zoom level starts at 1.2x and goes to 19x.
One disadvantage to the Playback system on a 24.6-megapixel camera is that it's very slow to bring an image up, especially if it's still writing to the card. I've pressed the Playback button a second time, and then a third, only to have the image finally flash to the screen after three seconds, then disappear for another two seconds, then reappear. Sometimes it gets even worse before I remember to just wait five or six seconds to see where the camera is in the cycle.
Once images are saved to the card, flipping between them is easy, and very fast. Just don't get stuck in Index mode, activated with the Display button. It takes some time to bring up those five thumbnails across the top. It's convenient if you have time, but not if you don't.
Tricked out. Thought I'd include a little eye candy, with the Sony A900 outfitted with a Sony 70-200mm f/2.8 G, the Sony HVL-F58AM flash, and the VG-C90AM battery grip. With two batteries in the grip, the combination weighs 7.63 pounds (3,464g). (The same grip fits the A850 as well.)
The function of the front and rear control dials varies from menu to menu, which can often leave you spinning the dial in vain waiting for something to happen. Sometimes it's one dial, sometimes it's the other, and sometimes it's both. In cases where only one dial controls a given function, it would make more sense for Sony to allow both dials to control the function.
Size has a price. There are those who go for the biggest and the best, and they're likely to slap down their largest credit card on the Sony A900 for 24.6 million little reasons. But while they're at it, I suggest they check their computer hardware and either upgrade or at least invest in redundant, multi-terabyte disks, because the Sony A900's files are huge. A typical outing for me with the Sony A900 is filling a 4GB card in a hot hurry. Some of that's shooting RAW, some of it is just the JPEGs I shoot, which average from 7 to 18MB each. Yes, I said 18MB for a JPEG.
Thankfully, Sony at least planned for the larger files and created a USB download pathway that is among the fastest we've ever tested, moving 12,568 KBytes per second. Still, when you take as many test shots as we do, it's an ordeal to move all these images around. The sample photos we've posted total almost 4GB of data.
No comments:
Post a Comment