1080i or 1080p

[Jemima Harrison]

We've made the decision to shoot 1080 over 720 for our next (PAL) project, but after a fair bit of reading, I'm still confused about whether we should shoot progressive or interlaced. We'll be delivering both for broadcast in the UK and internationally.

Any advice would be greatly appreciated!

Jemima
www.passionateproductions.co.uk

[Barry_Green]

Progressive 24P/25P = "the film look"
Interlaced = "the video look" or the "live look" or the "reality" look

That's the simplest summary possible (and no, shooting 24p by itself does not inherently make the footage look like a hollywood blockbuster movie of course!) but it's the single most important distinguishing factor between something that's obviously been shot on video, and something that looks like it's been shot on film.

So it depends on the nature of your production and what you want it to "feel" like.

[Jemima Harrison]

Thanks Barry. Apologies, I didn't ask the right question. I'm aware of the difference re look, but I'm notsure about the issues re converting from one to the other once it's been shot, in order to meet various delivery requirements (the film will be sold internationally in both HD and SD formats).

Which gives us the most options - interlaced or progressive? Or is it perfectly possible to convert effortlessly between them..?

Jemima
www.passionateproductions.co.uk

[Barry_Green]

If you want the film look, shoot 1080/24pA. You can edit that at native 24p frame rates and master a finished 24p version, and you can easily export one at 60i with pulldown inserted for broadcast requirements, and you can fairly easily convert 24p to 25p for Euro/Aus distribution.

[Milezee]

Hi Jemima,

here is a link for the beebs worldwide delivery specs that might be useful.

http://www.bbc.co.uk/guidelines/dq/contents/television.shtml#HDGuide

In it they state either 1080/50i or 1080/25ps, which leaves it as an asthetic choice for you.

I think if you are going for worldwide delivery and need differeing frame rates for those over the pond guys, I would seriously consider standards conversion with an established post house. I'm sure you know this but there are plenty of them in soho. I'd suggest somewhere like Ascent Media or On Sight. Wherever, as long as they do it with the Snell and Wilcox Alchemist Ph.C you'll get the best conversion possible.

Hope this helps.

[Jemima Harrison]

Thanks Milezee

Yes, we're aware of the BBC HD guidelines (this document over a year old now, frustratingly, so I'm hoping they'll update it soon), but thanks for posting them. We started filming today and have gone for 25p as we need to make our BBC UK delivery our priority. Still wondering if we're doing the right thing, though, and I'm still a little confused - not least to see that the LCD tells me it's recording 1080i/25p (surely cant be both.?); and also that it offers (or does it?) 1080/50p as a recording option..

We do already use Ascent for our WW deliverables and very good they are too.

Jemima

[mikkowilson]

1080/50P is not a shooting option in the HVX

The 'maximums' shooting modes of the (PAL) HVX:
1080/50i
1080/25p ( recorded as /50i )
720/50p
576/50i
576/25p

- Mikko

[Milezee]

Yes, you are shooting 25p.
As Mikko notes 1080/25p is recorded as 50i.

Its not an interlaced picture you're recording in this mode, its just the progressive frame is stored over 2 fields, I think for reasons of the DVC Pro HD codec. Hence the slightly confusing annotation 1080i/25p.

Good luck with the production!

[Jemima Harrison]

Thanks for the clarification...

As for the 50p, isn't this a pretty desirable option? I wonder why Panasonic hasn't allowed access to this.

Jemima

[mikkowilson]

Beacuse 1080/50p would require TWICE the datarate of 50i or 25P. With curent DVCPRO encoding rates, that would be about 200Mbps, just too much data.

720/50p works because the image resolution is rounghly half of 1080.

- Mikko

[Jemima Harrison]

Aha... that would explain it...!

I imagine that (50/60p) is what we'll all go to eventually, though, no?

Jemima

[Barry_Green]

Aha... that would explain it...!

I imagine that (50/60p) is what we'll all go to eventually, though, no?

Jemima

Yes, eventually. But right now there is no 1080/50p (or 1080/60p) production, acquisition, editing or broadcast standard in place.

But that is the eventual goal.

[mikkowilson]

..or maybe, just maybe (yeah, right!) we can have a single standard frame rate someday. Or better yet, total freedom of them (which would still be limited by the fastest frame transfer rate).


- Mikko ... wants a TV that will update when it receives a frame, and won't care how long until or how fast the next one comes.