Which HMC150 Recording Format to use?

[Twin Lakes]

I have two very basic questions concerning the many Recording Formats on the HMC150. My aim is to provide the best resolution and clarity on a DVD that will play on 4:3 or 16:9 television receivers.

Question One: Which recording format should I use - 1080 60i or 1080 24p (native)?

Question Two: Why does burning a DVD compress, for example, a 4GB project file to 2.2GB when 4GB will clearly "fit" a standard DVD+R disc.

I use a Sony VAIO laptop - VGN AW220J with 4GB of RAM. It has a built-in SDHC card slot.

I edit with Adobe Premiere Elements 7 (AVCHD compliant). Providing that I render all the video before starting the editing process, making a DVD is glitch-free. Adobe works beautifully.

Thank you.

 

[BobDiaz]

Let me break it down into parts:

Interlaced vs. Progressive:
I do NOT like working with interlaced, there are problems with freeze frame and slow motion with interlaced. Most on the forum will agree that progressive scan is the better choice.

1080 vs. 720 For SD Video:
If the end result is SD video, the difference between mastering and editing in 1080 vs. 720, then dropping to SD is very minor and may be very hard to tell. Because the HMC-150's sweet point is 720p video, my own personal feeling is that shooting and editing in 720p mode will work very well and produce great SD video.

60p, 30p, or 24p:
This one is a bit tougher to give a general answer, because it all depends on what you want. 60p offers the highest frame rate is is ideal for freeze frames, slow motion, and offers the best image for fast action. It is also the highest data rate of the 3 choices, thus the highest compression ratio. (Highest possible compression noise.) The counter argument is that the compression ratio is not that high, so who cares, the issue of compression noise is a moot point. 30p is a good middle ground. There is a problem with transcoding on some systems, because the transcoding software does not transcode the 720/30p video correctly. 24p is the same rate as movie film. Great for those who want the film like look and has the lowest compression ratio. The only downside is that you have to be careful with shutter speed and movement to avoid a strobe like look. In general I'd say 720/60p is the best bet, BUT there are reasons to chose other frame rates.

DVD Data Rates:
The maximum data rate for DVDs is 10 Mbps or about 1 hour on a 4.7 GB DVD. If your material is only 30 minutes, it would only fill 1/2 of the DVD. Had the software tried to fill the DVD, the data rate would need to be increased to 20 Mbps and few DVD Players would be able to deal with a data rate beyond the specification.

Another factor is the setting on the DVD burner program. The software may not be set to 10 Mbps. While I've burned several DVDs at the maximum rate, not all DVD players work well at this top speed. Burning the DVD at a slightly lower rate, like 8 Mbps or 7 Mbps increases the chances that the DVD player will be able to keep up with the data rate.

Now on an editing system, we want the lowest compression ration possible, so the data rate, even for SD video, is very likely to be higher than 10 Mbps.


Bob Diaz