Sony has been busy extending its DSLR Alpha range this week, with the arrival of the Alpha a500, a550 and a850 cameras.

The a850 is a strange beast and one that's sure to raise a few eyebrows, as it brings to the table nearly all of the functionality of its bigger brother, the a900, but with a smaller price-tag.

First things first: TechRadar would like to note that while the a850 does offer the opportunity to shoot full-frame images, the camera can't compete with the a900 in terms of viewfinder coverage.

While 2008's a900 has 100 per cent, the a850 makes do with 98 per cent viewfinder coverage. Also shooting has been reduced to 3fps, compared to the a900's 5fps. And the setup also now lacks a remote control.

As far as cost-cutting measures go, that's pretty much it. What you are left with is an almost professional camera, with some impressive features.

a850

When we got hold of the camera, it instantly hit us how close to the a900 it was in look and feel. Sony has definitely gone with the 'if it ain't broke' approach here.

It's a similar trick that they did with the a700 – a camera which Sony has told us will now slowly be phased out.

Although we had limited time with the a850, the camera is a sturdy bit of kit. The aluminium chassis feels good in your hand, with ample grip so you don't feel like at anytime you're going to drop what is essentially a beast of a camera.

a850

The high contrast 3.0-inch Xtra Fine LCD on the back of the cam is more than impressive. When viewing our image, the high-resolution 921k dot screen was crisp and clear even in stark light.

And the images you can view are impressive - the a850 sports a whopping 24.6MP Exmor CMOS sensor. Currently one of the biggest sensors around in the DSLR market.

We were also impressed with the Fn button, as it essentially meant that we didn't have to dig deep into the myriad menu options that the camera has to offer.

It also meant we could key in what shooting parameters we wanted quickly and easily.

a850

As with the a900, Sony has managed to squeeze its SteadyShot technology inside the a850.

This in-body optical stabilisation system essentially means you are no longer tied to using a tripod with your DSLR. It adds up to four steps of anti-shake correction, and makes handheld shooting a whole lot easier.

Alongside the a850, Sony is also releasing a 28-75mm F2.8 SAM lens. The company assures us that the lens is ideal for "interior scenes and available-light portraits".

While we are slightly concerned that the a700 is being dropped by Sony, the a850 is a more-than adequate step-up in the range.

a850

With a price of around £2,000 (compared to the a900 which currently retails at £2,400) it does mean that those who have been looking longingly at the a900 but haven't been able to afford to buy one, will do no wrong bagging the a850.

Release date for the Sony Alpha a850 DSLR is this September.