1080PA or 720PN for 35mm film out?

[Jon Fairhurst]

Originally Posted by Barry Green

...Everything about 1080 is just better...

The only exceptions to this are the additional storage space requirement and processing load, as Leonard mentioned. I think it impacts these three areas:

1) Half as much video fits on each P2 card. No big deal, if you're doing short takes, have enough cards, and have a good workflow for moving the bytes around.

2) You need twice as much hard disc space. Fortunately HDDs are cheap, and

3) The CPU has more work to do. As long as you have a strong enough system to preview things well, and allow enough time for your renders, it's likely not a problem.

If quality is more important than a bit of time and money, and you don't need variable frame rates, I'd shoot 1080.

And Barry's absolutely right about the true 24p thing. Think of it as a 24p product shipped in a 60i box. The extra fields that get thrown away are like Styrofoam packing materials - only they're easier on the environment. :)

[Scott Auerbach]

Originally Posted by Barry Green

Leonard answered this -- the only reason to opt for 720 is if you need more recording time on the cards. You trade a small (very, very small) reduction in picture sharpness in exchange for getting 2.5 times as much recording time. Lots of people seem to think the tradeoff is well worth it.

If I were going to HDTV, I'd agree. But for 35mm film-out, I think it's worth testing. Even minor differences in resolution aren't so minor when the image is that big. The HVX will only be the B-camera, but it'll be on-screen a lot of the time.

[Scott Auerbach]

Originally Posted by Jon Fairhurst

Think of it as a 24p product shipped in a 60i box. The extra fields that get thrown away are like Styrofoam packing materials - only they're easier on the environment. :)

Makes perfect sense now. It had just never been explained to me. Thanks!

[Paul Nordin]

[QUOTE=Barry Green]I haven't seen those tests, but I can say that something's wrong, that isn't true nor can it possibly be true. Someone messed up somewhere.

I'll see if I can get some examples of the test. It was run by some of the folks at PixelCorp who tested the HVX in 720PN, HVX in 1080P, Varicam, F900, and F950. The sole purpose of the test was to evaluate performace of the footage for CGI work. A quote from one of the sr.testers "...the edges of the 1080p footage from the HVX was -softer- and harder to get a crisp matte, given the option use 720PN..."

Sure there are lots of variables with tests, and I did not personally perform it. But I did talk with one of the testers who is a friend of mine and who I trust. I'll see if I can get more details of the tests to post so you can draw your own conclusions.

Cheers

[Seth Melnick]

My 2 cents here.

Test what you will be shooting in the format you want to shoot- We shot our feature at 720 - we performed a film out test with that and it stood up very well to a film out. So the added storage and processing and reduced p2 time of 1080 werent justified - we were thrilled with the quality of 720.

Make sure you need 1080 if you use it - if you dont need it you will be swapping cards more then you need to and peforming backups and backups more then you need to - the on set workflow is not trivial.

see my report on the filmout here
http://www.dvxuser.com/V6/showthread...hlight=filmout

and you can see trailers from the film here (uncolor corrected) - http://www.americanstandardthemovie.com/media.html

[Jon Fairhurst]

Originally Posted by Paul Nordin

...A quote from one of the sr.testers "...the edges of the 1080p footage from the HVX was -softer- and harder to get a crisp matte, given the option use 720PN..."

I think I can explain this...

If you're looking at a given screen size, 1080 gives you more resolution PER INCH than 720. It doesn't give you the full 50% resolution improvement that is theoretically possible, due to the limited resolution of the imager. People here have estimated that you get about 20% more resolution with 1080 than 720. This could be important for film out. The movie-goer will potentially see a 20% sharper image.

Now zoom in to the pixel level. 1080 is 1.5 times more dense in one dimension than 720, yet it's only 1.2 times sharper. That means that the 1080 version is only 80% as sharp as 720 PER PIXEL (1.2 / 1.5 = 0.8).

Chromakeyers don't care how big the screen is. They work on a local group of pixels. While the audience sees 1080 as sharper across the screen, the chromakeyer sees 1080 as softer on a pixel-by-pixel basis.

All things being equal, the chromakeyer would give a thinner green outline (per inch) on 1080 than 720, assiming both are projected on the same size screen. However, if the soft transition confuses your chromakeyer in 1080, but the sharper 720 transitions are interpreted well, 720 might give the better chromakey than 1080.

That's my theory anyway.

BTW, I rent an HVX tomorrow. It's time for me to dump the theory and get practical for a change!

[Scott Auerbach]

Originally Posted by Seth Melnick

My 2 cents here.

Test what you will be shooting in the format you want to shoot- We shot our feature at 720 - we performed a film out test with that and it stood up very well to a film out. So the added storage and processing and reduced p2 time of 1080 werent justified - we were thrilled with the quality of 720.

Make sure you need 1080 if you use it - if you dont need it you will be swapping cards more then you need to and peforming backups and backups more then you need to - the on set workflow is not trivial.

see my report on the filmout here
http://www.dvxuser.com/V6/showthread...hlight=filmout

and you can see trailers from the film here (uncolor corrected) - http://www.americanstandardthemovie.com/media.html

Thanks for the link... some interesting info there, especially about print versus camera stocks for film-out.

Nothin' to do at this point except test!