View Full Version : 1080p vs. 720p


Brian Petersen
August 16th, 2005, 12:14 PM
When we finally get the HVX200 is there any reason why one would choose to shoot in 720/24p when they have 1080/24p available to shoot? Granted storage space is an issue, but if that is out of the equation are there any reasons, technical or asthetic, why someone would prefer to shoot in 720p?

I would be using this camera for independent shorts and features and my thought was that I would use the 1080/24p mode for most shooting and then us the 720/30p/60p and what other intermediates they give for any "slow motion" effects. Would the 1080/24p and the "slow motion" footage shot at 720p edit together without techinal problems or big visual quality differences?

Thanks,
Brian

Steven White
August 16th, 2005, 12:51 PM
Would the 1080/24p and the "slow motion" footage shot at 720p edit together without techinal problems or big visual quality differences?

The 720p footage has exactly half the resolution of the 24p in the DVCPRO-HD format. The visual quality difference will be akin to de-interlacing for slow motion - but without the interlace problems. I suspect that the majority of users will do their final render to (square pixel) 1280x720p as opposed to a 1080 format - so that 1/2 resolution drop won't be too significant in the end... especially if properly managed.

Frankly, I think this whole "720p for slow mo" idea is really overrated. 2.5x slow motion is really not that much when you get down to it... and the increased sharpness in the 1080p storage will be significant enough that people won't bother shooting much 720p content as soon as they iron out the memory issues.

-Steve

Charles Papert
August 16th, 2005, 02:13 PM
Steven:

I would have to say that 60 fps can be deceiving--certainly not enough to shoot in "bullet-time", say, but makes a significant difference to human activities, action scenes etc. And with good interpolation software, a further 50% reduction should be able to deliver a credible 120 fps, which was for years the top speed of standard-issue film cameras (until the Arri 435 came out around 10 years ago, which offers 150 fps). I think it's a significant technological achievement to be offered at this price point, even at 720p.

Eric James
August 16th, 2005, 04:23 PM
I completly agree with Charles on this point. It is a very big deal that we (indie filmmakers) have yet another storytelling tool that was once reserved for hollywood. Try to find a hollywood action movie that doesn't use slow-mo and you'll see how important it really is.

My 2 c,
Eric James

Jacques Mersereau
August 16th, 2005, 04:27 PM
Agreed. There are positives and negatives with every choice.

One thing is assured, either HD format will blow the doors off of DV (or NTSC).

BTW, nice HD100 work Charles, Barry and Nate!

Dan Vance
August 16th, 2005, 06:19 PM
...120 fps, which was for years the top speed of standard-issue film cameras (until the Arri 435 came out around 10 years ago, which offers 150 fps).
25 years ago, or more, you could walk in to any of the big rental houses (Birns & Sawyer, Alan Gordon, etc.) and pick up a 400fps Milliken or Photosonics camera for special slo-mo shots. I guess you can call those "non-standard" but similarly, the Arri435 is then non-standard if all you need is 150fps, and in the digital realm, using interpolation software just to try to get to 120 fps is a non-standard process.
I understand the point you're making and I agree, but I just don't want readers to get the idea that 10 or 20 years ago it was in any way difficult to get 150fps and higher on film. It just wasn't/isn't.

Charles Papert
August 17th, 2005, 01:12 AM
Dan:

Certainly it wasn't impossible or even hard to shoot high-speed, but I think it's still a valid distinction to make; Arri 3's or, later, 435's are not exotic birds and may even be part of a full-time camera package on a given job, whereas Photosonics are more of a special order that often comes with its own tech. I do think it safe to consider up to 150 fps "standard" slow motion and the higher frame rates (I've personally done up to 2000 fps) more of a special effect, i.e. non-standard.

But this is all just subjective nomenclature. Point taken that we should make a distinction between that which was and is possible, and that which is simply somewhat exotic.

Dan Vance
August 17th, 2005, 04:31 AM
Yes, I think the distinction you make is valid and appropriate. Well said.