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General HD (720 / 1080) Acquisition
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Old February 7th, 2010, 11:13 AM   #1
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Are you shooting progressive or interlaced?

First of all, sory for my english. I really don't know what format should I choose. I live in Europe. This is my usual outputs:
1) internet (YouTube, Vimeo)
2) DVD (PAL)
3) TV broadcast on a small local TV station (PAL DV Widescreen, interlaced)

I'm shooting mostly interviews, promotional videos and sometimes short movies.

What format should I use? Is there a difference between shooting interlaced or profressive when the output is just interlaced (DVD, TV) or just progressive (YouTube, Vimeo)?
What format are you using and for what kind of productions?
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Old February 7th, 2010, 11:19 AM   #2
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I shoot progressive, 1080p30.

It helps with green screen composites and also makes it possible to get good results whenever I need to re-scale an image to crop out unwanted portions of a frame or just tighten up a composition slightly.

Interlaced footage doesn't scale well. And it's a mess when it comes to doing green screen.
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Old February 7th, 2010, 03:21 PM   #3
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Peter - as you are in Europe, you want to stick with standards based on 50Hz, so 1080p/30 would not be a good idea, it's only relevant to the US and other countries with 60Hz mains frequencies.

If you shoot progressive, there are two basic choices - 25p or 50p. The former gives "film-like" motion (or jerky) which may be suitable for drama, but is not likely to be so for fast action such as sport. 50p is much better for fast action, and gives the more normal motion rendering, same as normal PAL interlace TV.

If you want 1080 line resolution, then for progressive you only have the choice of 25p - 1080p/50 is unrealistic currently for most equipment. If you actively want "film-look", it's almost certainly the best choice. If you want "normal motion", and also progressive, then it has to be 720p/50. Half the resolution of 1080p, but it does mean 50 full progressive frames per second. It is also good for downconversion to standard PAL interlace (576i/25), as there is a discrete progressive frame able to be used for every PAL field.

Of course, a lot depends on camera. Not all can do 720p/50, in which case you have to use 1080i/25 if you want smooth motion. And if the end product is standard definition, why not use an SD camera in the first place?
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Old February 8th, 2010, 04:55 AM   #4
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I now shoot 1920x1080i 25np all the time for delivery to all formats on my P2 cameras.
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Old February 8th, 2010, 07:48 AM   #5
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I shoot 30P as over 90% of my deliverables go to the web. 30P is easier to handle on DVDs for those occasions where I need to deliver DVD. It looks fine on TVs. LCD TVs are actually progressive displays, so 30P looks great on them. Only tube TVs have difficulty displaying a progressive signal. But chances are if someone still has a tube tv, they are not that discriminating about quality.

There is a good argument for shooting 24P, but with 30P it's easier to mix 60i material in there when you need to.
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Old February 8th, 2010, 10:50 AM   #6
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It depends on what your client wants. I suspect you local TV may be shooting interlace, so if you're shooting material that inserts into their productions follow their practise.

For short films etc 25p is pretty common for a film look.

30p is very much NTSC territory, although if you're shooting for the web that's ok. However, European cameras are usually set up for 25 fps and for PAL clients that's the way to go.
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Old February 9th, 2010, 10:38 AM   #7
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I didn't say I wanna shoot 30p :-)

Ok, I got it. Thanks for explanations. Just for curiosity and clarification - lets say I shoot the same short film progressive and then interlaced and then I export both movies (independently) to interlaced PAL DV or PAL DVD (PAL DVDs are allways interlaced, or not?). Would it make any difference, or both footages will look identical?
And second eample - if I shoot some sport interlaced and then progressive and I put both results on internet (progressive output), would it make any difference?
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Old February 9th, 2010, 07:22 PM   #8
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The above question is impossible to answer as it stands. By "shoot progressive", do you mean 25p (25 progressive frames per second) or 50p (50 progressive frames per second)? In each case you are "shooting progressive", but the answer to your question will be completely different between the two scenarios.
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Old February 10th, 2010, 04:06 AM   #9
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Quote:
Originally Posted by Peter Berger View Post
I didn't say I wanna shoot 30p :-)

Ok, I got it. Thanks for explanations. Just for curiosity and clarification - lets say I shoot the same short film progressive and then interlaced and then I export both movies (independently) to interlaced PAL DV or PAL DVD (PAL DVDs are allways interlaced, or not?). Would it make any difference, or both footages will look identical?
And second eample - if I shoot some sport interlaced and then progressive and I put both results on internet (progressive output), would it make any difference?
They will look different. How different depends on a number of factors - the sort of screen they are being viewed on, the content of the footage, etc. But they will definitely look different.
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Old February 10th, 2010, 10:27 AM   #10
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Quote:
Originally Posted by Peter Berger View Post
First of all, sory for my english. I really don't know what format should I choose. I live in Europe. This is my usual outputs:
1) internet (YouTube, Vimeo)
2) DVD (PAL)
3) TV broadcast on a small local TV station (PAL DV Widescreen, interlaced)

I'm shooting mostly interviews, promotional videos and sometimes short movies.

What format should I use? Is there a difference between shooting interlaced or profressive when the output is just interlaced (DVD, TV) or just progressive (YouTube, Vimeo)?
What format are you using and for what kind of productions?

For all forms of web video - vimeo, YouTube, etc) - stick to Progressive. Interlaced video is only applicable to 'Cathode Ray Tube' TVs and high end LCD/Plasma screens. And the latter will deinterlace anyway.

When you convert interlaced video to deinterlaced video, there's two ways it's going to happen: either you lose 25% of your vertical resolution, or you lose 50% of your resolution.

When it comes to TV, you may be aware of a BBC programme called Top Gear. I had the opportunity to watch an old episode recently (there seems to be little chance of finding a station that ISN'T repeating it every hour of every day). It was shot interlaced, with the smooth 'video motion'. I can't put this gently: it looked cheap.

We associate the 25p progressive look with film, and film suggests big budgets, and so 25p - like it or loath it - pulls a production from being 'shot on video' to 'shot on film'.

The issues with shooting 25p are down to 'judder' with quick motion. We're taught about this in film school - don't pan too fast, follow a fast moving subject by keeping fairly tight on it. But some will feel this doesn't suit their content.

So if you shoot sport, action and 'energy' stuff, you'll prefer interlaced modes. But in these days of HD, I'd suggest 720p50 or 720p60 - 50 or 60 progressive frames per second, currently only achievable on affordable equipment at 1280x720, not 1920x1080. Certainly no broadcasters are doing nationwide 1080p50 or 1080p60 yet.

But for interviews, corporates and web material, stick to 25p, enjoy the expensive look, don't drink too much coffee before operating your camera.

If you're doing TV spots, talk to them beforehand - shooting 720p50 is good for downsampling but may take too much time. Many cameras will supply progressive material (which scales well for internet, looks nice) as 'progressive segmented frame' - it IS interlaced video but looks and works just like progressive. Maybe your station will be happy with this - even prefer it if it adds production value.

BTW - The web can do any frame rate you choose, though it soaks up more bandwidth. If you want DVD, then 720p50 can be made into Standard Definition 50i to retain the smooth motion.

I've not shot interlaced video in... wow, three years now. No need, no desire. But if I were shooting sport/action, I'd shoot 720p50. Still progressive...
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Old February 10th, 2010, 11:18 AM   #11
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Quote: If you want DVD, then 720p50 can be made into Standard Definition 50i to retain the smooth motion.

This prompts me to ask a question.

For 30P and 25P, many people favor shooting at 1/60 or 1/50, respectively, to simulate a 180degree film shutter.

Shooting at 1/60 for 720p60 (or 1/50th for 720p50) would be equivalent to a 360degree shutter. So what's the right shutter speed to use if you plan to convert back to SD 25i or 30i?
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Old February 10th, 2010, 11:33 AM   #12
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Because you're shooting at 50p, it would be 100th; and shoot at 60p, use 120th. Nothing wrong with that, except the loss of one stop of light. You're not going to get that zingy juddering (Top Gear, Private Ryan, Gladiator) because the fields will sort that out for you, but it will be a little zingier than standard SD.

But my EX1s will do 720p50 at 60th, and with shutter off, that makes it 50th.

So if you can switch the shutter off, you'd get the equivalent of your standard motion blur.

But run some tests on the sort of motion you're working with. DoPs will tell the difference, but what of your audience?
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Old February 10th, 2010, 11:38 AM   #13
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I guess, but people dont usually use 1/120 or 1/100 when filming i30 or i25 ... trying to get my head around what will best simulate the "normal" look of SD, when its being derived from 720p60 or 720p50.
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Old February 10th, 2010, 12:50 PM   #14
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HD could be academic if Czech TV has no plans to go for High Def in the near future. A lot of countries will be using SD for a while yet and it will depend on the camera you're using. Betacam SP is still being shot in places.
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Old February 10th, 2010, 07:11 PM   #15
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Quote:
Originally Posted by Craig Parkes View Post
But they will definitely look different.
No, not necessarily. Not in the most important respects. (There may be some difference - but there's likely to be between two different cameras anyway.) Reasons being as Matt goes into above.

"Progressive" tends to get (incorrectly) used to refer to 25p - progressive, at 25fps - but it can just as easily mean 50p.

Mix 25p with "normal" interlace footage and yes, there definately will be a difference. Mix 50p in with interlace and the biggest differences will go away, certainly when coded for SD or the web.
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