Shoot 1080p24 with the Panasonic HDC-HS100 and HDC-SD100
The HDC-HS100 and HDC-SD100 are the new kids in the AVCHD town. It seems that Panasonic finally stopped dumbing down its cameras, though obsession with size and weight is still there. The new cameras signify that Panasonic cares about geeky videographers once again.
Of course, the autopilot controls are still there, but for the first time since the venerable PV-GS400 a consumer camcorder from Panasonic has all the right features in one package: a viewfinder, an accessory shoe (standard-sized, not proprietary fare), a microphone input, a headphone output and a real focus ring. As if this is not enough, the camcorders offer 24-fps progressive recording capability, which is the topic of this article.
True progressive recording
First of all, the camcorders do not shoot at actual film 24-fps rate, they shoot at television-friendly 23.976-fps. Most camcorders do so, because this rate can be easily converted for NTSC television broadcast. But because "23.976" is much harder to write and say than "24", everyone calls it simply "24p".
Both camcorders are capable of shooting 24p video with 1920x1080 frame size, this is TrueHD in marketing speak. The camcorders are capped at 17 Mbit/s data rate, which is on par with the Canon HF10/HF100 cameras but below what Canon HF11/HG20/HG21 can offer at 24 Mbit/s rate. In native interlaced mode this indeed puts newcomers from Panasonic in the middle of the pack, but 24p mode brings them to the lead.
The thing is, these new Panasonic camcorders record 24 frames per second, progressive, full-frame-at-a-time video straight to a file. No 2-3 pulldown is employed, there are no duplicate fields. Heck, there are no fields at all, video is recorded frame by frame, not field by field. All available data rate is used as efficiently as possible. On contrary, the Canon camcorders repeat one field for every four original fields, potentially losing up to 20% of bandwidth.
Another huge benefit of true progressive video is that it does not require deinterlacing, so editing, scaling and distributing is easy. Film-mode deinterlacing, also known as inverse telecine (IVTC) is a relatively simple procedure, but it requires time and often money. Not all editing applications are capable of doing inverse telecine, so you have to resort to third-party tools. Also, every reencoding degrades original video, so you want to avoid extra reencodings if possible. The IVTC is not needed with 24p from the new Panasonic cameras.
The cameras can record at four quality settings, but 24p recording is possible only at two highest-quality modes, HA at 17 Mbit/s and HG at 13 Mbit/s. Of these two the HA is the obvious choice not only because of higher data rate, but also because it is a variable bitrate mode. This means that when a scene has little detail, the data rate drops to save bandwitdh. On contrary, in the HG mode the camera records at constant date rate just like an old-fashioned tape-based camcorder.
A slight problem with 24p mode on the new cameras is that it automatically turns on the Digital Cinema mode, which boosts color. This can be mitigated by reducing color saturation from a separate menu. Also, you can always reduce saturation in an editing application. You will be editing your 24p footage, won't you?
First of all, check out this sample video that I shot at an electronics store, it will give you some idea about motion rendering in 24p mode: http://www.vimeo.com/1865441. Depending on your computer, the video may stutter excessively even if it is fully buffered. In this case download a 720p WMV file, you will find the link on the Vimeo page.
If you want to play with raw files, here are the links to some clips I used in the test video (click on a still image to get the original raw AVCHD clip).