Panasonic HDC-SDT750

Back at the end of July 2010, Panasonic announced the upcoming release of the world's first 3D consumer camcorder, the SDT750. This model is not only the first product to break into a whole new market, but it'll also be sold with a relatively reasonable price tag of around £1,300. This brings it in line with many other HD consumer camcorders, even though it can film both 3D and 2D Full HD footage. Still sound expensive? Well, bear in mind that the first HD camcorder to be released in 2004 (Sony HDR-FX1) launched at £3,000, and it wasn't until 2006 that consumers could film in HD for under a grand.

Handling

The SDT750 comes in two component parts: a removable 3D conversion lens and the camcorder body. The camcorder body is an exact copy of the Panasonic SD700, released at the beginning of the year. The controls are laid out in exactly the same way (including the 1080p mode), but there is one major difference, as the SDT750 menu now contains a 3D calibration programme that you won't find in any other camcorder on the market (at the time of writing). The 3D lens can therefore not be hooked up to any other camcorder, as it simply won't work without the internal calibration function. In any case, the lens is not available to buy separately.

Three separate wheels are used to adjust the three axes of the 3D lens.

The 3D lens fits over the regular camcorder lens and has a diameter of 46 mm. It can be a bit tricky to lock in place correctly, and we found ourselves turning and turning it round for a while before it finally clicked into place. The 3D attachment actually houses two separate lenses that film two separate pictures simultaneously. The 3D films you may have seen at the cinema are filmed by placing two video cameras next to one another, and then the footage is combined to give a three-dimensional effect. This, however, is a very expensive technique. What's more, the bandwidth of the AVCHD format can't support two simultaneous HD streams. Panasonic has therefore come up with a clever way to get around these two problems: combine the two images captured simultaneously into one, single AVCHD file. Indeed, the SDT750 films two images in 960 x 1080 pixels, which it then sticks together to make one composite image of 1920 x 1080 pixels (960 x 2 = 1920). This allows the camcorder to handle 3D footage like any other HD footage. It's actually the 3D TV you'll play the file back on that will then display the AVCHD file in 3D. The only real problem this created is with video editing (see insert).
The camcorder detects the 3D lens automatically, but once it's attached you do need to calibrate it. A menu pops up on the screen to guide you through the process step by step. Three small wheels located just above the lens are used to adjust the three 3D shooting axes so that they line up with a target printed on the lens cap. It's therefore important to make sure that you've attached the lens to the camcorder correctly as any gap, wobble or incorrect placing can affect the calibration process. Once the lens has been calibrated, you can crack on with filming in 3D, although the camcorder's LCD screen can only play back 2D images. Note that you have to check the calibration each time you remove and re-attach the 3D conversion lens.

Image Quality

Adding the 3D lens does impose a few restrictions. First of all, you can't zoom, as the 3D lens has a fixed focal length. In order to zoom, the lens would have to integrate two synchronised zooms, which would be very complicated to make and too costly for a consumer model. Second, the diaphragm opens to f/1.5 in 2D but just f/3.3 in 3D, as focusing is easier with a smaller aperture. As a result, the sensitivity of the SDT750 is noticeably not as good in 3D. Our tests showed a minimum operational light level of 3 lux in 2D (which is pretty good) and of 28 lux in 3D (which is quite bad). Finally, the wide-angle focal length is 58 mm (in 24 x 36 mm equivalent) compared with just 35 mm in 2D. The field of view is therefore very tight.

So what does the resulting footage look like on a 3D-compatible TV? We viewed back our rushes on the 42-inch Panasonic GT20 3D TV, which is compatible with 'side-by-side' technology. The result was quite simply excellent. Smaller objects filmed at close range seem to literally jump off the screen, in spite of the very small distance between the two lenses. The final image really does look three dimensional, just like at the cinema (you have to wear the glasses, don't forget). The TV automatically detects the presence of an SD card and the 3D files contained on it. It then separates the two images captured by the camcorder and displays them side by side to create a 3D effect that comes to life as soon as you put on the special 3D specs. Plus, the 3D image looks just about as sharp as the 2D picture.

The really great thing about the SDT750 is that it can also be used as a regular Full HD camcorder. In 2D, the results are very similar to the TM700. Colours are well balanced and the automatic white balance is very responsive. The image captured is clear and sharp, and is much better quality than in certain competitors' models (Sony CX550, Canon HFS21). It's also sufficiently sensitive in low light. Footage is recorded in the AVCHD format in 1920 x 1080 pixels. A 50p mode is also available but pictures are no sharper than in 50i. However, using 1080p avoids you having to de-interlace footage to post it on the web.

Finally, this camcorder's connections hold two pleasant surprises. First of all there's a microphone entry and, even more unusually, a mini-HDMI cable is supplied for instant connection to an HD TV. What more could you ask for?