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Choosing an HDV CameraHeath McKnight discusses HDV camcorders from JVC, Sony and Canon
What is color space?Color space is all part of resolution, alongside Luma (light). To put it simply, DV color space (NTSC) is set at 4:1:1 sampling, but HDVs color space is at a 4:2:0 sampling, giving it the edge. Photoshop and the web are effectively working in a color space similar to HDV. People using NTSC may notice colors shift when importing a photoshop project into an NTSC timeline. Douglas Spotted Eagle goes into greater detail in his book, HDV: What You NEED To Know.
This articles goal is to help with your decision of what camera is right for you. Well be taking a look at the many models offered by JVC, Sony and Canon (the fourth company that supports HDV, Sharp, has yet to release a unit, over three years after joining the others), and giving you enough information to help you make a solid decision.
First, a short primer on what HDV is. In the beginning, JVC released the HD10 (pro) and HD1 (consumer) camcorders that shot in a resolution of 1280x720, well over the ATSCs specifications of what HD is (anything over 576 lines of vertical resolution). But it wasnt 100% HDV, since it still had NTSC mini-dvs color space of of 4:1:1 sampling, and more , but it recorded into an mpeg2-ts compression stream , allowing the HD signal to go onto a small mini-dv tape.
By September 2003, Sony, Canon and Sharp joined JVC and formed a consortium to develop and support HDV, which they described as being either 1080i60/50 or 720p30/25. By 2006, they added 30p, 25p and 24p to the 1080 specification, and 60p, 50p and 24p to the 720 specification. HDV also requires the same frame size and color space, no matter the frame rate, unlike NTSC and PAL DV/SD (720x480i60 vs. 720x576i50, for example). The color space is now sampled at 4:2:0, , as explained in the first sidebar, which is more powerful to work with, and like the HD10/1, it still uses the mpeg2-ts (transport system) to compresses the robust HD signal down to either 25 or 19 mbps (1080i/p vs. 720p) to still fit onto a mini-dv tape. If the signal is recorded digitally without a mini-dv, technically its no longer called HDV.
What is mpeg2-ts?
If youre familiar with how DVD is compressed, through mpeg2, youll be familiar with how HDV is compressed. Essentially, audio and video, whether its for a DVD or HDV, is muxed, or combined, into a stream via mpeg2 (a compression scheme developed by the Motion Pictures Expert Group) and is ?shrunk in size to fit on a disk, or in this case, a minidv tape, which keeps the tape manufacturers from having to create new assembly lines. The ?ts stands for transport stream, which is how the HDV signal is placed into the mpeg2 compression. Its inter-frame compression with a long GOP (group of pictures) that has an I-Frame (intra-frame) every 15 frames and a P (Predictive) or B (Bi-Directional) frames in between. What does this mean? Basically, unless there is a lot of movement in a frame, the first I-frame will have the entire image, then the rest of the frames will reference anything that isnt moving to the I-Frame and will only ?re-draw what has moved. This saves a lot of space, but a drop-out on the I-Frame will last up to 15 frames, or the next I-Frame.
Despite the higher amount of compression vs. other HD codecs, the look of HDV is crisp and clear, and is definitely an advantage to moving up into the high-def world. And since the manufacturers of these cameras have experience in professional mini-dv units, the ergonomics of the HDV cameras are familiar and easy-to-use.
The JY-HD10u, admittedly, isnt much of a professional camera and its identical to the consumer version, the GY-HD1u. There arent any true manual controls and with its one CCD, it handles color pretty badly, resulting in chroma noise, which can make darker areas of a shot have small little artifacts of small pixels of RGB visible. It made one actress hair look greasy, when I showed a short film I directed to an audience. You also couldnt control the audio without a mixer, and early models had a ?tinny sound when audio was recorded via the unbalanced inputs. But, when used properly, it could produce some nice results (visit http://www.lumieremedia.com/thetrap/ to see how Frederic Haubrich handled the camera, and www.releasememovie.com to see how cinematographer Jon Fordham and I used it). The camera has since been retired, and will be remembered mostly for the revolutionary aspects of giving us an HD camera for less than $60,000, with lens. The HD1 is still available from JVCs consumer division.
The JY-HD100u was also short-lived, only because JVC put out the more-advanced HD110, which I havent used yet. But from what my colleagues have told me, its very similar to the HD100, which is a great 720p camera. With it, JVC started dubbing the unit as ProHD, because of the better audio qualities (PCM vs. HDVs standard MPEG1 Audio Layer II). Its a shoulder-mount camera, similar to many broadcast cameras, and has a interchangeable lens, so videographers and cinematographers will feel more comfortable if they are used to handling cameras like this, as they are similar to BetaSP, DVCPro and other broadcast and higher-end HD and SD cameras.
The HD100 also offered 720p30 and now 24p, the first HDV camera to do so. It could handle great tripod and handheld shots, works well with both natural and artificial light (and a mix of both), it has a nice cinematic look to it and offers a better image overall than its predecessor, the HD10. The HD110 adds the option of adding an Anton Bauer battery onto the unit (the HD100s standard batteries, when fully charged, would last around 3-5 minutes before dying). The three 1/3 inch CCDs have an image sensor of 1280x720.
One problem in the early HD100 models that has disappeared from the 110 was the ?split screen effect, which showed one half of the image as being darker. Ensuring the camera had time to warm up and avoiding using a gain setting higher than 3db helped out, but again, the 110 seems to have fixed this.
In the higher end range, JVC has the HD200 and HD250, which adds the ability to put 16mm film lenses on the units, more recording features (60p/50p in HDV mode vs. DV), and Genlock and HD SDI out on the HD250. Pricing for the units is around $6,500 for the HD110, $9,000 for the HD200 and $11,000 for the HD250.
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