Sony’s Alpha DSLR-A900 feels like it’s been with us for a long time – after all, the prototype was first shown back in March 2007 and its sensor unveiled in January 2008. So unlike its rivals which are often sprung with little notice, we’ve long-known what Sony’s flagship DSLR would look like and speculated how its new 24 Megapixel full-frame sensor may perform in practice.

Despite this advance information though, using the A900 in person is still quite a surprise in a number of respects. First, it’s larger and heavier than it looks, and once equipped with a quality lens like the Carl Zeiss 24-70mm f2.8, you certainly know you’re carrying it around. This is not a combination for anyone who wants to travel light, but it does feel well-balanced in your hands and like most heavier cameras, this heft instils a degree of confidence. It should also be said, the A900’s very distinct styling comes across better in the flesh than in photographs – it’s a unique but smart-looking camera.

The Sony A900 has to rank among the most anticipated digital SLRs in recent memory. The company first showed an early version of its upcoming flagship design at the Photo Marketing Association tradeshow in the spring of 2007, and at the following year’s show Sony revealed a few more details about the image sensor and stabilization mechanism it would use. With the Alpha A900 featuring a full 35mm frame-sized image sensor, Sony has joined a rather exclusive club. To date only four companies have offered full-frame digital SLRs. Of these, two - Contax and Kodak - have since left the digital SLR market altogether.

It is designed to deliver ultra-fine picture quality with the world’s highest resolution, 24.6-megapixel, 35 mm full-frame CMOS sensor and fast image processing with a new dual BIONZ® processing engines. The camera is also the first to have a body-integrated image stabilization system for a full-frame sensor with Sony’s SteadyShot® Inside anti-shake system.

One look at the camera’s distinctive pentaprism and nostalgic body design will evoke its full-frame optical performance. It features a bright, clear optical viewfinder with 100% field of view coverage that would impress even film photography loyalists.

The primary advantages of having a digital sensor the same size (24×36mm) as a frame of 35mm film are (1) higher image quality, especially in terms of noise and especially in lower light situations, and (2) the ability to use very wide angle lenses. The only disadvantage to having a full-frame sensor compared to a small-sensor digital SLR body (Canon Digital Rebel or any Nikon) is that the small-sensor effectively increases the magnification of telephoto lenses, which can be useful when you are doing sports or bird photography. Of course, the resolution of the 5D is so high that you could pull out the central 8 MP of a Canon EOS 5D image and it would be almost as though you had taken the photo with a Canon 30D or Digital Rebel.

If you are a wide-angle junkie and have a bunch of older Canon EOS lenses designed for film cameras, you’ll love having the EOS 5D. The small sensor Canon bodies turn an exciting 20mm wide angle lens into a boring 30mm perspective. With the 5D, what you got with your 20mm lens on the film camera is what you get with the 5D.

At around $3000, the Canon EOS 5D is currently the lowest cost full 35mm frame DSLR available. In fact it’s the lowest price full frame DSLR that ever has been available. The EOS 1Ds Mk II sells for in the region of $7200 and right now that’s the only other option for a full frame 35mm DSLR. The Kodak 14c had a pretty short life which perhaps say ssomething about it’s practicality and problems with noise and speed of operation. The EOS 5D is not only cheaper, but a far more practical camera with better usability. much faster operation and an ISO range from 50 to 3200 with good image quality.

The EOS 5D will likely be regarded as something of a landmark camera and shows how much digital technology has advanced in only a few years. The first “affordable” DSLR was the Canon EOS D30, a 3MP APS-C sensor camera which sold for $3000+ in October 2000 (Original price 380,000 yen). In only 5 years (October 2005) we now have a 12.7 MP full frame camera selling for about the same price ($3000). In another 5 years I would not be surprised to see a 15MP full frame camera selling for under $1500. However the 5D will be seen as the “full frame” breakthrough camera, just as the D30 is seen as the first really practical and affordable DSLR. 5 years prior to that all you could get was a 1.3MP DCS 3, and it would have cost you almost 2,000,000 yen (almost $20,000) or a 6MP DCS 1 selling for 3,600,000 yen (upwards of $30,000). I’m sure the rate of progress is slowing down now as the technology matures, but it certainly hasn’t stopped!

The new PENTAX K200D dSLR is designed for the novice photographer. Yet it includes many advanced features including a 10.2-megapixel CCD sensor, a weather-resistant body and in-body anti shake & dust removal systems. As the replacement for the K100D the K200D is chock-full of user-friendly features and sophisticated functions borrowed from higher-class models. Even digital camera newbies will enjoy the advanced features of this new model.

PENTAX uses a 10.2-megapixel CCD image sensor in the K200D. All that resolution means you can print larger and sharper images that ever before. The high resolution CCD combines with a DDR2 memory image buffer to give quick capture rates up to 2.8 frames per second. The body of the K200D is designed so that every button and dial is in easy reach. This makes shooting a simple, intuitive operation.

The new model has a larger LCD than previous models, now up to 2.7 inch LCD, keeping it in line with its competitors, though not the largest, while the new Dynamic Range Enlargement feature is also something we’ve seen in Nikon and Sony models for example. Another addition that brings the K200D up to speed with its rivals is the Dust Detect feature that allows you to check the sensor for dust by taking a picture of a white wall or piece of paper and seeing a high-contrast lithograph-type image on the LCD. The sensor can then be cleaned if necessary.

Almost exactly two years after the D80 was announced comes its replacement, the rather predictably named D90. The D80 has been one of Nikon’s quiet successes, and even today, despite being positively Methuselah-like in digital camera terms it continues to sell and often makes its way into our top 10 most clicked on cameras. Because it looks so similar to the D80 the D90 appears at first glance to be one of those rather subdued incremental upgrades, but dig a little deeper and you’ll find there’s plenty to keep Nikon fans happy.

With 12.3 megapixels, the newly-designed DX-format CMOS image sensor and Nikon’s proprietary EXPEED image processing concept, the D90 is a quality-guarantee. Advanced features such as Live View, Scene Recognition, Active D-Lighting, Picture Control and an ISO sensitivity range of 200-3200 (ISO 6400 equivalent on Hi1 and ISO 100 equivalent on Lo1), allows creativity in almost any setting. And to ensure all these features are easy to use, they are packed in an ergonomic body with an intuitive operational layout.

The D90’s EXPEED technology has been optimised to realise the high-quality, high-speed image processing capability for which Nikon’s professional D-SLRs are renowned. The D90 delivers images with extraordinary detail and expanded enlargement capacity, thanks to its improved DX-format CMOS image sensor and an effective 12.3 megapixels. The ISO sensitivity ranges from 200-3200 (ISO 6400 equivalent on Hi1 and ISO 100 equivalent on Lo1) providing low-noise images that are rich in detail and offer tonal gradation beyond expectation. It also enhances the performance of other powerful features such as Live View and the new Face Detection System. To address the issue of lost detail in high-contrast lighting situations, Active D-Lighting adjusts the contrast between images’ light and dark areas by localising tone control as an image is captured. And for extra creativity, Picture Control allows you to customise the look and mood of your images by choosing from six settings, including new Portrait and Landscape modes.

Canon broke with its tradition of upgrading the line every 18 months, introducing the EOS 50D just 12 months from the introduction of the 40D. The move has helped Canon catch up with the Nikon D300, which made quite a splash in the market. With the same rugged, conservative body as the 40D, the Canon EOS 50D’s only distinguishing mark is the silver bezel on its mode dial. There are a few minor changes to how the buttons and controls are used, but for the most part the Canon 50D’s body is unchanged.

he 50D features a proprietary CMOS sensor with an effective 15.1 megapixels of resolution (an increase from the 40D’s 10.1 megapixel sensor), a new DIGIC IV 14-bit image processor, a new menu system, and better weather sealing where the various parts of the camera body come together. The 40D’s bright viewfinder with interchangeable screens and nine-point auto focus system return, with the addition of live view with enhanced contrast-detect AF. The 50D also gets a new “Clear View” 3.0 inch LCD with improved resolution and greater visibility in direct sunlight.

LCD size, resolution, and sunlight readability is particularly important for the 50D since it sports a live view system, allowing the screen to be used for shot composition. The 50D’s live view implementation is a significant improvement over the first-generation live view feature on the 40D, with the addition of a contrast-detection AF mode that allows the camera to auto focus without interrupting the on-screen preview as on the 40D.

The Megapixel-count may have increased by around 50%, but there’s only a fractional drop in continuous shooting performance with the EOS 50D boasting 6.3fps to the 40D’s 6.5fps. Image processing is courtesy of the latest DIGIC 4 which offers ‘Peripheral Illumination Correction’ on JPEGs to reduce the effect of vignetting where the image darkens towards the corners. Staying on the subject of lenses, the EOS 50D also features the welcome facility of fine-tuning the AF on lenses, inherited from Canon’s pro range.