Comparing HDV (Sony, Canon, JVC) with DVCPROHD (Panasonic)
HDV records HD video to miniDV tape, a standard never intended to record HD. To accomplish this trick, a lot of information has to be dropped out. First, HDV compresses a block of frames at a time. When you go to edit HDV, the non-linear editor has to decompress groups of frames just to display one frame, which makes HDV editing very CPU intensive and reportedly slower. DVCPROHD is far less compressed than HDV. Each frame is compressed separately, so editing takes a lot less CPU. In fact, when I’m editing DVCPROHD on my Mac G5, I don’t see any performance difference – it edits at the same speed as standard definition DV for me. Less compression means that DVCPROHD is too big to record to miniDV tape. And a high definition tape unit that could record DVCPROHD would cost as much or more than the whole camera. As far as the quality of the image, HDV and DVCPROHD are pretty comparable. HDV shoots in true 1280x720 pixels and then it drops the color to 4:2:0, which is similar in quality to 4:1:1 SD DV color. DVCPROHD, on the other hand, squeezes the horizontal resolution. So instead of recording in 1280x720, it actually records in 960x720 pixels that has to be stretched out in 1280x720 in post. So DVCPROHD seems has effectively 1/3 lower horizontal resolution than HDV. On the other hand, resolution is not the only thing that determines image quality. Because DVCPROHD records in the 4:2:2 color space, that additional color adds color information that isn’t present in HDV. In my opinion, HDV looks sharper but less colorful, more like video, while DVCPROHD looks a little softer but with much richer colors, more like film.
Workflow and Ease of Use
If you just want to shoot in SD to miniDV tape, there is one switch and one button that you have to press to turn the HVX200 into an SD DV camera. And if you know the menus and features of the DVX100, a few minutes becoming familiar with the different layout of the HVX tape menu will have you up and shooting rapidly.
On the other hand, if you want to shoot in HD, and really get the value out of the camera’s features, then there is a significant learning curve. Well, actually, it’s three learning curves: there is the transition from the simple SD format to the much more complex suite of HD formats (that’s not the camera, of course, that’s the technology); there is the transition from working with miniDV tape to working with digital files; and finally there are the cinematic features of the camera.
Learning Curve #1 -- HVX200: HD Formats
The HD standard is actually a suite of 18 specifications or formats for recording and playing video. Several of these standards (called “480”) duplicate standard definition video, so you can record in HD/480 and you are really recording 720x480 SD DV video into a digital file. The HVX200 supports 13 of the 18 formats. The ones that it doesn’t support are the really high-end ultra-high-resolution HD formats that require special and very expensive hardware to capture and edit. Besides the standard definition equivalents, the HVX records in several flavors of “720” and “1080”. 720 is 1280x720 resolution, and 1080 is 1920x1080. But because of the way DVCPROHD compresses video, 720 is recorded as 960x720 anamorphic pixels, that have to be stretched out to 1280x720 in post. And 1080 is recorded as 1280x720 that has to be stretched out to 1440x720 in post.
The above diagram describes the physical resolution, or frame resolution. There is also temporal resolution – or how much information is communicated over time. Progressive video means that every horizontal line is recorded or played at the
Progressive, or “p” mode is expressed in the numbers of frames per second. In interlaced, or “i” mode, each frame is divided into alternate lines, all the even-numbered lines are called the upper field and all the odd-numbered lines are called the lower field. Interlaced mode is expressed in number of fields per second. So 30p video is 30 frames per second, and that is the same amount of information as 60i, or 60 fields per second. Interlaced video tends to look artificially sharper or more detailed, but it doesn’t portray faster motion as smoothly as progressive video.
