720 vs 1080

by shooting 720 the bandwidth of data isn't pushed to the extreme as much as it is with 1080. 720 and 1080 are both being shot at 21-24mbs, so if that amount of data is put into a larger frame size then there will be less data.
 
manglerBMX said:
by shooting 720 the bandwidth of data isn't pushed to the extreme as much as it is with 1080. 720 and 1080 are both being shot at 21-24mbs, so if that amount of data is put into a larger frame size then there will be less data.
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720p60 gives you overcranking so that's the big benefit/agument for 720p. In theory 720p is less compressed than 1080p due to pixel count & data rate but I haven't noticed ANY blockiness in any of the 1080p24 I've shot. Even an extreme shot in total darkness with a backlit silhouette showed no visible compression artifacts when viewed on my Sony PHM-14M8U HDVS monitor.

For me it depends on what the client wants, last shoot they wanted 1080p24 so that's what I shot except for some 720p60 for overcranking testing

-Shrigg
 
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Hey Shrigg,

So overcranking would mean dropping a 60p clip into a 30p timeline? Would that make is 50% slo mo? Or do you still need to slow the clip to 50%?

I have read about people taking 60p footage and dropping it into a 24p time line. Is that even better slow mo? ]

So the HPX170 offers multiple frame rates and overcranking like the HVX200. So would you say the HMC150 has an official overcranking feature? What the heck does HMC, DVX, HVX, and HPX all stand for anyway?

THansks

Thanks.
 
Correct, with 720p60 clips, a 24p timeline plays back slower than 30p.

In FCS2 I reconform the 720p60 to 720p24 using Cinema Tools and the clip plays back as slow motion. I don't know how other NLE's handle this.

I'd call it an unofficial overcranking workaround.
 
Sharpness wise, not too much is gained in 1080. Theoretically it could have more color information and hold the best results for keying. I agree with Shrigg that 1080p24 still holds out really well with the codec. For now I prefer 720 because it looks about the same, the 60p option, and the lighter load on the computer when editing. If/when Panasonic releases a more hi-rez chip in this range, I think 1080p will hold up well with AVCHD and become more useful.

With most NLEs you can't just drop the clip in to get slowmo, you have to set it to play back at the percentage you want (50% for 60 to 30, %40 for 60 to 24). In terms of the file format, this isn't true overcranking since it doesn't know you want to slow it down, but as far as you are concerned, it works the same way once it has been edited properly.
 
If we compare 1080/24p to 720/24p, the 1080 file has 2.25x as many pixels to deal with. So, the 720 file has less video compression.

In studying the different files by doing a freeze frame and zooming in, the level of compression noise on the 720/24p footage is really hard to find. It's a bit easier to find it on the 1080/24p footage, but the level of compression noise is still very small and hard to spot.

Using the test charts from VideoMaker, it looks like the 1080p mode gives us around 10% to 20% more detail over 720p mode, BUT I'm going from one test and I can't be 100% sure of the results.


Bob Diaz
 
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