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Sony Alpha A900: Specification
- Resolution: 24.6Mp
- Sensor size: 35.9x24mm (full frame)
- Sensor type: CMOS
- Image size: 6048x4032
- Focus system: TTL phase-detection
- Focus points: 9 points with centre dual-cross centre & 10 assist focus points
- Crop factor: 1.0x
- Lens mount: Sony A mount, Konica Minolta A mount
- File type: JPEG, RAW, cRAW
- Sensitivity: ISO200-3200 (true), expanded ISO100 & ISO6400 is also available
- Storage: Compactflash, Memorystick
- Focus types: Continuous, single, auto, manual, direct manual
- Metering system: TTL, 40 segment honeycomb pattern SPC
- Metering types: Multi, spot, centre-weighted
- Exposure compensation: /-3 EV in 1/3 or 1/2 step increments
- Shutter speed: 30sec - 1/8000sec & bulb
- Frames per second: Maximum 5fps
- Flash: Hotshoe
- Flash metering: ADI/pre flash TTL
- Flash sync speed: 1/200sec
- Image stabilisation: Yes
- Integrated cleaning: Yes
- Live view: No
- Viewfinder: Optical, 100% field of view
- Monitor: 3in Xtra Fine LCD, 921,600dot (307,200px)
- Buffer depth: 105 (JPEG, 12 (RAW, 10 (RAW JPEG)
- Interface: USB 2.0, HDMI
- Power: Li-Ion battery
- Size: 156.3x116.9x81.9mm
- Weight: 850g
Placed at the £2000 price point, it looks certain to compete with the Nikon D700. The Sony has twice as much resolution but not as high sensitivity probably linked to the resolution.
Sony Alpha A900: Modes and features
Sony have a dream. That dream is to take the number one slot from under the noses of Nikon and Canon and relegate them to second and third place. The release of the A900 will hopefully strengthen their position.
At 24.6Mp, the resolution is higher than Canon EOS 1Ds MkIII making this the highest resolution full frame DSLR in the world today. All these pixels are sat on Sony's brand new full frame Exmor sensor which, the Sony website says, "assures extraordinary detail and a wide dynamic range."
Sony are really proud of the process involved with getting an image from the lens to the memory card. With pixels sitting close to each other being a contributing factor to noise, good noise control is a must on a sensor that has more than twice as many pixels than the Nikon D700. To combat this, the A900 has analogue noise reduction performed before the captured pixels are converted through the on-chip A/D converter. Noise is then digitally reduced after conversion before processing through one of the two new BIONZ processors and saved to memory card.
The fact that Sony have put two processors in the A900 the same as what Canon did with the 1Ds MkIII shows that they're thinking about the time it will take to process and download such a large file size. It also helps with keeping the frames per second rate at the maximum 5fps as the camera will designate the image to whichever processor will complete the task quicker.
This illustration shows the process of how the sensor, digital noise reduction and dual processors help to combat noise. Extracted from Sony UK website.
The Sony has a maximum sensitivity of ISO3200 with a boost of ISO6400. These settings will be really interesting to see in the performance area but don't look yet because the A900 has some other really interesting features you need to know about.
The Alpha A900 has an image preview option which is more like preshot preview than live view. It allows you to take a low resolution picture, using the depth of field preview button on the underside of the lens mount, which will pop up on the LCD screen as a thumbnail with histograms and all your options. You can then start to adjust the white balance, aperture, dynamic range (using the Dynamic Range Optimiser) and shutter speed ready for taking the picture. The good thing is that the camera will show you on screen what the adjustments will do to the shot. It then automatically remembers those settings for the shot you take next meaning you don't have to keep taking shots, reviewing them, discarding them and retaking them.
It's a really useful feature if you shoot still life, landscapes or you have a model that doesn't move. One major drawback to the fetaure is the lack of a focus checker. It would be great to go into the shot and see if it's focused so it can be trimmed if necessary.
For astronomic photographers, the A900 has had a mirror lock up feature added to it along with an eyepiece blind to stop any stray light getting on the sensor.
All DSLRs have some kind of image stabilisation to help keep your pictures straight but all others are lens based. The A900 is the first to offer in camera image stabilisation, or Super Steady Shot (SSS) as a camera based feature. The sensor is fitted with carbon fibre actuators which move the sensor in all directions to compensate for your natural movement. The result must be pixel perfect with such a high resolution as it will show up easier than a lower resolution image. In essence, when it's being employed the sensor is staying still to keep in line with the scene and the camera is moving around it.
A major plus to camera a based system is that every lens will benefit from stabilisation and there's no bend in light from the stabilising optic found in the lens.
A quick tour round the camera shows a surprisingly small body. Focus options are on a vintage style switch at the bottom of the camera on the face along with the depth of field preview button on the opposite side of the lens. There's also a large rubber cover which hides the flash sync port.
The top plate has been kept minimal with a large command dial on the left shoulder and plays host to a smattering of features including the standard PASM controls, auto and three custom user modes. A lot of DSLRs in the A900 class offer pre-set modes such as landscape, portrait and macro but then also offer picture styles with the same options. Sony only offer the picture styles which is a much better idea in my opinion as it reveals an uncluttered mode dial. Traces of Minolta remain with the inverted hotshoe still a firm favourite of Sony. I've never been a fan as I've always thought of it as a marketing ploy to making consumers buy branded products instead of generic. However, the inverted hotshoe is more stable then the regular one.
The left shoulder of the top plate houses four dedicated buttons for exposure compensation, continuous shooting, white balance and ISO. These are set in a square and link directly to the small LCD display. A small light button will illuminate the screen in dark areas. Further forward towards the edge of the grip is the shutter release and finger wheel. The eagle eyed will notice a small ridge running down the edge of the grip on the front of the camera. This is a finger divot to allow more room for your fingers and aids with grip when you hold the camera with one hand.
The minimalist design of the top plate has been thrown out of the window for the back with its bustle of buttons, switches and even a mobile phone style joystick. The reasoning behind this is that Sony aren't fans of buttons doubling up features which is why there's more than usual. The ones they've used have been done wisely, there isn't a function on the back that you wouldn't use a lot of the time.
Below the viewfinder are two eye sensors which cut out the screen when you put your eye to it. This is reminiscent of the old Minolta Dynax system with eye start and grip sensors. The grip had two nickel strips which would detect the moisture from your hand and start the camera up. This technology was revived for the release of the Sony Alpha A700 but a few weeks before the release, European legislation changed forbidding the use of nickel for tasks that gives prolonged contact with skin. Because of this, Sony have had to replace the strips with plastic and removing the grip start technology. That's why the A900 hasn't had the technology fitted. Ironically, Sony have worked out that the grip sensors would have to be in constant contact with your hand for 16 hours before you'd have an allergic reaction.
Sony Alpha A900: Build quality
The pre-release model was built on top of an aluminium chassis and was complimented with magnesium alloy plates for added durability and strength. This has been revised and now the whole chassis is magnesium alloy.
The mirror is a full frame type to give 100% coverage and has been covered with a special new coating to added reflectiveness giving a brighter image. It sits in a carbon fibre mirror box and has been redesigned with a double hinge which doesn't simply flip up but actually raises up as well. This means it doesn't have to swing 90 degrees so Sony could have a camera that wasn't as deep. Another benefit means less movement from the mirror which means less vibration when shooting fine detail.
The camera is weather sealed which means you don't have to run inside screaming when it starts spitting. The buttons and switches have rubber sealants on the inside but the memory card door has no rubber lining. This is a new design by Sony called the Labyrinth Seal. It works by creating a tightly sealed interlocking layer that water can't navigate through. This means there's no forcing the door closed because of springy rubber bouncing back.
The screen on the back of the A900 has 921k dots which equates to around 307k pixels. Similar to the Nikon screens and even Canon are now using the same resolution. It offers high performance in terms of brightness, clarity and colour. However, while using the A900 I found that sometimes when I was happy with the contrast or exposure of the image on the screen, it looked nothing like on the computer.
It makes me think that older technology doesn't simply disappear but moves around and pops up in an advanced state somewhere else. Here, the A900 has the same joystick that older SonyEricsson mobile phones once used. Those joysticks that had a tendency to stop working in the eleventh month. I hope these haven't come from the same place or Sony are in for a rough ride.
Sony Alpha A900: Performance
Sony have been very careful in the market placing of the A900 and are quick to let me know that it's not a professional DSLR that could compete with the likes of the EOS 1D series or the Nikon D3. They're happy to let it run slightly below that classification and compare with the Nikon D700 or Canon EOS 5D MkII.
All three are full frame with the Sony offering the highest resolution. This isn't necessarily a good thing where noise is concerned but Sony appear to have gone to great lengths in order to combat the phenomenon.
The large file sizes created from this amount of pixels have caused me a problem showing them to you. Save to Web can't cope with this amount of information complaining it didn't have enough scratch memory. I have therefore resized the images to 4000 pixels in order to get a decent performance in terms of download speed.
Primary colours are nicely boosted and the earth colours are rich. I'm unsure of the pastel colours looking so muted.
I'm really impressed with the colours from the colour chart test. The primary colours are nicely saturated with more prominence given to blue and the earth colours are rich. The skin tone tile looks a little paler than what I'm used to but it's not unappealing. The mono tones are well balanced and my only gripe is the faint pastel colours down the left side of the blue, orange and brown. They look a bit too muted against the actual colour chart.
I took two test shots of the landscape image at f/8 and f/22. I used the Sony 35mm f/1.4 G lens for all image quality test shots. There is some orange fringing on the white bars on both shots but this is more than likely attributed to the lens than the microlenses on the sensor. Both images have good level of detail with the f/8 image being sharper.
Landscape image at f/22.
Landscape image at f/8.
The portrait shot in Portrait Picture style.
The portrait in Standard Picture style.
I took two portraits in aperture priority. One was in the portrait picture style and the other was in standard picture style. The image taken in standard picture style has used a slightly faster shutter speed but there are more interesting things that have happened to the images.
First of all, despite being in aperture priority, I had to boost the exposure compensation by 0.7 to get a reasonable exposure. It seems that using a slightly slower shutter speed isn't acceptable. Secondly, the portrait picture style has a slight cloudiness to it. I've boosted the exposure in curves to highlight the problem. The image on the standard shot is much sharper but the picture styles can have sharpening added to them.
Staying with the picture styles and the colours of the autumn trees have accentuated the increase or decrease of colour with different picture styles. In this scene, I shot on standard, natural and vivid which has given a low, middle and high setting of colour boost.
I think the vivid colour really helps in this particular scene to punch the yellows of the leaves out. It does have a tendency to underexpose slightly which could need to be corrected on some images but by and large it gives a nice effect. The natural colour image has it's own benefits such as saving time if you enjoy the current fashion of desaturating shots.
Standard colour setting.
Natural colour setting.
Vivid colour setting.
Sony Alpha A900: Focus and metering
The Sony Alpha A900 has nine focus points which doesn't really compare with the 51 point AF system found on its rival, the Nikon D700. However, when the 10 assist points are added to the count, it has a larger amount of focus points than the newly announced Canon EOS 5D MkII which shares a nine point AF system but only has six assist points.
These assist points only work in the wide AF mode and are designed to help keep track of a subject. They sit either side of the main focus points and are there to effectively widen the focus point area for if the subject moves. It means the gaps between focus points are smaller meaning you're less likely to lose your subject.
The focus screen is the standard G type but is a spherical acute matte screen for increased performance. It's interchangeable with the two other screens available which are the L type which has a grid added to aid in composition while the M type is the super spherical acute screen which, Sony say, is best used with bright lenses of f/2.8 or greater as it is a high dispersion screen which is better for manual focusing.
An additional AF-A option has been added to the focus switch on the front of the camera. This an "Automatic AF" option that will switch between single and continuous shooting dependant on whether your subject moves or not. On the back of the camera, next to the metering switch is an AF/MF button and this will temporarily switch to manual focus when you're in AF mode allowing you to adjust the focus ring. The process works in reverse if you're in manual focus.
The three metering modes aren't supplemented by additional features within the menu system unlike the garrison of AF features in the shooting menu. The switch is on the back of the camera next to the viewfinder. You can choose from centre-weighted, spot or multi metering. You can enjoy the D-Range optimiser and exposure compensation which are tied to metering.
Sony Alpha A900: Noise test
Sensitivity rises in 1/3 stop increments and it would be exhaustive to put every single step onto the page. From ISO200 to ISO3200 is Sony's true sensitivity with equivalents down to ISO100 and as high as ISO6400.
As an eqiuivalent, ISO100 has produced a lovely image with bags of detail and a nice smooth grey card. If I was being highly critical, noise is starting to creep through at ISO400 but it's really small and only seen at full size magnification. In fact, noise can't be seen at 25% (fit to page) until around ISO3200 which is a really good result.
Detail is starting to fade out of the flower at this stage and by ISO6400 there's a massive leap in quality degradation. I've also uploaded a RAW version of the ISO100 and ISO6400 images for comparison. Noise on the ISO6400 RAW image is terrible and takes a lot of detail away.
The ISO100 equivalent test.
The ISO200 test.
The ISO400 test.
The ISO800 test.
The ISO1600 test.
The ISO3200 test.
The ISO6400 equivalent test.
The ISO6400 in JPEG/RAW comparison.
||DxOMark provides objective, independent, RAW-based image quality performance data for lenses and digital cameras to help you select the best equipment to meet your photographic needs.
Visit the DxOMark website for tests performed on the Sony Alpha A900.
Sony Alpha A900: Verdict
The A900 is a bold first step for Sony in different ways. It's their first full frame camera and is their first semi-pro model. Buying Minolta's camera division was a good idea as they've gained decades of SLR experience as well as a lens mount that is well established. Couple that with a collaboration with the greatest lens maker in the world and Sony are looking prettier everyday.
Sony already have third place in the DSLR market and are hot on the heels of the big two. All Sony need to do now is release a pro-spec DSLR with spectacular noise performance to compete with the D3 and EOS 1 series and Sony could pull it off.
The Alpha A900 isn't the prettiest of cameras but the ugly angles of the prism help you get a brighter image in the viewfinder. It appears to have something for everyone without shoving a load of pre-set modes on it.
Astronomical photographers will enjoy using the mirror lock up and viewfinder blind while studio photographers can use the flash sync port and remote trigger software. There are loads of lenses available for other genres and Sony are proud that their G range covers nearly every focal length.
After seeing the camera, playing with it and looking at the results, I think if you're not tied down to a system or have a load of Minolta AF lenses lying around, look at this camera.
Sony Alpha A900: Plus points
Bright viewfinder and mirror
Camera based IS
Good noise control
Good colour rendition
Remote trigger software
Sony Alpha A900: Minus points
Portraits under exposed slightly
Joystick could cause problems later
Intelligent preview has no focus control
Because of so many plus points as well as a decent price for what you get, the Sony Alpha A900 has been awarded our Highly Recommended award.
The Sony Alpha A900 costs around £1793 body only and is available from Warehouse Express here.
You can view the video review at ePHOTOzine.tv by clicking the link here: Sony Alpha A900 video review.