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Adam Letch July 12th, 2007 08:29 PM

HD251 50P DVD delivery question
 
Hi guys,

i had a brief search on this, but I'm in the Australian outback, and internet time is short.

I've had a opportunity here to shoot a rodeo horse rider doing his tricks on his cattle station here, he wants to use it for a promo tool to get sponsors for the circuit. My question is, obviously as it's pretty fast action that 50p would be better to capture it, but if we're distrubing in Pal land on a DVD which is 25p is it not?
Do you think it's better for me to just capture 25p and only use 50p for slowmo's, or can i shoot and deliver 50p, and therefore do most domestic dvd players play 50p?
Sorry I know this may seem elimentary to a lot of you, but I'd greatly appeciate the heads up!

Thanks

Adam

Tim Dashwood July 12th, 2007 11:41 PM

PAL is 50i with 25P compatibility (both fields sourced from a single progressive scan.) Depending on your workflow you could capture 50P and downconvert to either 50i (to maintain fluid 'video' motion) or 25P (to obtain a 'film-look.')
Obviously 50P for overcranked slow-motion (50% speed) is a huge advantage as well.

David Scattergood July 13th, 2007 04:42 AM

I assumed 50p would be used for faster moving projects/sport etc, less filmic than 25p but retaining that non-interlaced look. I didn't realise that you would have to then down convert this to 50i or 25p.
Does this mean that if broadcast footage was shot progressively at 50p (in PAL land...say for foootball) the station would then downconvert accordingly for broadcast?

Tim Dashwood July 13th, 2007 10:59 AM

Quote:

Originally Posted by David Scattergood (Post 711432)
Does this mean that if broadcast footage was shot progressively at 50p (in PAL land...say for foootball) the station would then downconvert accordingly for broadcast?

That's right... at least for the PAL broadcast. The HD broadcast (assuming EBU) would be in native 720P50.

David Scattergood July 13th, 2007 11:35 AM

Quote:

Originally Posted by Tim Dashwood (Post 711576)
That's right... at least for the PAL broadcast. The HD broadcast (assuming EBU) would be in native 720P50.

That's suprised me somewhat (not that I had a lot of 'backup' to suggest otherwise). I honestly presumed 50p would be a format in it's own right go to speak i.e. recorded in 50p and shown in 50p...but of course HD broadcasts would be a different story (and I guess where I got a little foxed).
I believe the EBU are now edging towards interlaced broadcasting over progressive broadcasts - initially it was felt they were edging towards progressive.

Has any 50p footage (specifically 720p50) been shown on these boards? I'm still intrigued as to what this would appear like (and I'm guessing as it would be downconverted to SD then it would resemble a more fluid 25p?)
Cheers Tim.

Adam Letch July 13th, 2007 04:49 PM

thanks guys
 
I'll see if I can get away with 25p and a few 50p shots thrown in for slow mo, I shot a rodeo the other day and it seemed to work ok. I just can't get around my head at the moment shooting 50p and making it 50i.
I'm weakest in my knowledge when it comes to post production, guess it's going to be a wait and see learning curve for me.

cheers

Adam

Tim Dashwood July 13th, 2007 07:33 PM

Quote:

Originally Posted by David Scattergood (Post 711593)
Has any 50p footage (specifically 720p50) been shown on these boards? I'm still intrigued as to what this would appear like (and I'm guessing as it would be downconverted to SD then it would resemble a more fluid 25p?)
Cheers Tim.

Temporally, 50P feels just like 50i to me. I probably wouldn't be able to tell the difference between a 1080i50 broadcast or a 720P50 broadcast. The benefit of the 50P is that you have twice as many complete frames to work with for slow motion replays in sports.

Brian Ladue July 13th, 2007 09:47 PM

I have a question, and this is for us over in NTSC land. If i shot 720p60 and wanted to deliver it as 60i would that be possible? or would the only advantage of shooting 60p be for slow motion use on a 24p or 30p timeline? And i also understand that the latest update for Edius Pro has added a 60p timeline, so would i be able to edit 60p and treat it as 60i from start to finish? I am going through the HD110/200 purchase decision. And i'm wondering if 60p could be used just like i use 60i today, and if i would be able to output to SD DVD in a format that will be compatible with current DVD players. Thanks

Tim Dashwood July 13th, 2007 10:40 PM

Quote:

Originally Posted by Brian Ladue (Post 711848)
I have a question, and this is for us over in NTSC land. If i shot 720p60 and wanted to deliver it as 60i would that be possible? or would the only advantage of shooting 60p be for slow motion use on a 24p or 30p timeline? And i also understand that the latest update for Edius Pro has added a 60p timeline, so would i be able to edit 60p and treat it as 60i from start to finish? I am going through the HD110/200 purchase decision. And i'm wondering if 60p could be used just like i use 60i today, and if i would be able to output to SD DVD in a format that will be compatible with current DVD players. Thanks

It wouldn't be too much of a problem to do what you suggested. There are obviously different ways to do it on different systems.
I would maintain a 60P timeline until the cut is locked, and then downconvert the final cut to 480i60. Depending on what tools you use to downconvert you should find that the upper and lower fields are sourced from adjacent frames, therefore using all 60 frames per second as fields.


The option for slow motion is always there with 50P or 60P.

David Scattergood July 14th, 2007 04:29 AM

Quote:

Originally Posted by Tim Dashwood (Post 711808)
Temporally, 50P feels just like 50i to me. I probably wouldn't be able to tell the difference between a 1080i50 broadcast or a 720P50 broadcast. The benefit of the 50P is that you have twice as many complete frames to work with for slow motion replays in sports.

I'm astounded that interlaced broadcast would look almost idential to progressive broadcast - I'm sure if somebody with your knowledge and experience cannot tell the difference then I guess the any viewable differences are negligable. I'd question shooting sports in 25p though so I guess those wishing to see sports shot progressively are referring to 50p (I know you can track moving object well in 25p but the rest of the action would just be a messy blur).
Do you still have to ease back on the pans tilts with 50/60p or are you free to move the camera as you would with a 1080i50/60 camera? I was thinking that some projects require 1080i50 but if I could (if I were to upgrade) utilise 720p25 and 720p50 with the same camera then that would be ideal.
Very interesting....thankyou.

John Mitchell July 17th, 2007 07:51 AM

Just to clarify, there are three free to air national networks in Aus and one Government funded broadcaster. All still broadcast in analogue SD 576i50, and all run an SD digital service in parallel with their HD digital service.

HD wise, Nine and Ten broadcast in 1080i (1440 x 1080 @ 50 interlaced fields per sec). Seven I thought broadcast at 720P25, but according to a website they are the same as the ABC @ 576P25 (which isn't really HD at all).

All the other stations are regional or pay. Regional are HD, pay is a highly compressed SD digital multichannel service, run side by side with an older very noisy looking SD analogue service.

For the rodeo you may be better off shooting everything 50P for later down conversion to 50i - this should give you your best result and the most flexibility. I wouldn't do this without testing your NLE path.


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