Part of the problem is the high bit rate that the 50p mode records at (28Mbps). But even a quad-core Windows 7 PC with 8GB of memory and a powerful graphics card struggled to play back our test files smoothly. Transferring the footage to a PlayStation 3 console with its famous Cell processor and Full HD support gave us even worse results. Pans, zooms and practically any on-screen movement were rendered as a spluttering, stuttering mess.
Interestingly, certain PC-based media-player applications seemed to handle the files better than others. Nero Showtime, for instance, played our progressive footage with virtually no problems, while Windows Media Player and VLC both chugged through it like they were suffering from the video equivalent of a coughing fit. Presumably, the problem lies in the AVCHD codec and, specifically, the way it's decoded in a particular media player. As such, this is a situation that could well improve as new media-player software is released. In the unlikely event that you're happy just playing back your footage on the camcorder itself, you should never encounter the problem.
We should also point out that we had no problem playing back the footage we shot at any of the HDC-TM700's 1080i settings, either on our test PC or PS3. In fact, at the highest 1080i bit-rate setting (17Mbps), footage was nigh-on exceptional, with rich, balanced colours and a phenomenal level of detail.
There's no denying that £850 is a sizeable wad of cash to pony up for a camcorder, but the Panasonic HDC-TM700 certainly delivers on the feature front. It's a shame, then, that the fun is spoiled by a couple of potentially crippling problems. Technically speaking, the progressive-playback issue isn't a fault of the camcorder itself, so we haven't marked it down for that. But prospective buyers interested in the HDC-TM700's 1080/50p video will need to ensure that their playback and editing hardware and software is up to the task of handling the camcorder's raw footage.
Edited by Charles Kloet