Converting 720p to 720 interlaced??? - Page 2 at DVinfo.net

Go Back   DV Info Net > JVC ProHD & MPEG2 Camera Systems > JVC GY-HD Series Camera Systems

JVC GY-HD Series Camera Systems
GY-HD 100 & 200 series ProHD HDV camcorders & decks.


Reply
 
Thread Tools Search this Thread
Old December 12th, 2006, 10:27 AM   #16
Trustee
 
Join Date: Mar 2004
Location: Milwaukee, WI
Posts: 1,719
Even sports can look good at 24p if done the right way. Any Hollywood movie that deals with sports is shot at 24p. "We are Marshall" and the new "Rocky" movie are prime examples of new sports movies.

Intercutting progressive and interlaced is a big no no in my opinion. Unless it is being done for an clear effect such as a MTV type piece. One of the reasons why movies work at 24p for us is because everything from the beging including the titles is 24p so our minds get used to the motion and view it as normal. As soon as you add just a few seconds of interlaced you throw the brain off and it triggers that something is odd about the progressive footage.

Learn to shoot with care. Wipping the camera around like a rabid dog is not good shooting even if interlace is forgiving of it. If you keep trying to compare 24p/25p/30p to interlaced TV then you will never be happy with it.
Thomas Smet is offline   Reply With Quote
Old December 12th, 2006, 11:08 AM   #17
Major Player
 
Join Date: Aug 2005
Location: Belgium
Posts: 497
Quote:
Originally Posted by Marijn Schuurmans
I've shot a videoclip in Pal 25p. Now they want to broadcast it interlaced from a DVCam recorder. Will I loose resolution?
Thanx.
You will. Theoretically you don't need to, but practically you will and you have to. the lines are somewhat averaged, thus causing loss of resolution.

That is not such a bad thing in itself - it is just a necessety. If it would be converted to interlaced and the total sharpness of the progressive footage would be kept, that would mean that details and lines that are just 1 line thick would start flickering if you saw 'em on an interlaced TV-set. To avoid that you need to drop resolution a little, thus softening those 1-line details but retaining a flicker-free image.

try e.g. putting a high-res picture of a tree in the fall on interlaced video(when all the indiviual branches are in plain sight - some of them are bound to be very thin lines) - the tree will seem to shake right out of the image.
__________________
High-Definition Video Consultant - CEO of Delimex NV - http://www.delimex.be
gear of choice : http://www.wespgear.com
Werner Wesp is offline   Reply With Quote
Old December 12th, 2006, 07:15 PM   #18
Tourist
 
Join Date: Jul 2006
Location: Amsterdam Holland
Posts: 4
thanks a lot for the info. And if I turn it into 50p and then print it to tape, will this also be a way to get rid of details flickering when broadcasting interlaced? And is the frame rate of PAL always 25?
Marijn Schuurmans is offline   Reply With Quote
Old December 12th, 2006, 07:29 PM   #19
Major Player
 
Join Date: Aug 2005
Location: Belgium
Posts: 497
Hey Marijn, It won't make no difference. but I'm not sure what you mean with print it to tape. Take a look at my website and send a mail, I can answer you in dutch, that might be a little easier. (Thursday I'm close to Amsterdam, by the way. If you have some time we can discuss it over a beer...)

For now: the flickering will only be reduced if the averaging is done (that is the drop in resolution). The 'frame-rate' of PAL is always 25. But that means 2 things: PAL progressive will be 25 frames (true and whole frames), PAL interlaced will be 50 fields (and thus 25 'frames')
__________________
High-Definition Video Consultant - CEO of Delimex NV - http://www.delimex.be
gear of choice : http://www.wespgear.com
Werner Wesp is offline   Reply With Quote
Old December 13th, 2006, 07:56 AM   #20
Major Player
 
Join Date: Apr 2005
Posts: 512
Quote:
Originally Posted by Ken Hodson
If you can't shoot properly, don't shoot with a progressive cam.
And now I can't shoot properly? Funny, they keep hiring me back...

Quote:
I have seen more then a few interview type films shot at a mere 24fps film never mind 30fps and of course they look fantastic.
I never said that 24/30p looked bad by itself. I said it looked bad when cut with high temporal resolution footage at 60i/p in a broadcast setting. Read my post before responding kthx.

Quote:
Of course if you must shoot in an ENG fashion, with random cam swings and simply in a way that suits interlaced video there is always the 50p/60p SD mode to fall back on.
I hardly regard 50/60p mode as something to "fall back on," but rather as the primary mode to shoot in when shooting for a broadcast environment where the dominant standard has a scan rate of 50/60 Hz. Shooting 30P for a show that's 60p on the air is like shooting SD for an HD show. And I resent the implication that I'm simply randomly swinging the camera around. Have you ever shot sports?

Quote:
Otherwise don't use a progressive cam.
I will use whatever equipment that suits my needs. Just because your end product requirements are different than mine doesn't mean the same product can't fit both of our needs. JVC's made a great camera for both indie film and ENG styles of shooting, yet you seem to think there's no need for its ENG side. You should visit pro.jvc.com sometime. Right on the front page is a graphic for the HD250 that says "HD ENG SPORTS." They're not marketing this thing toward indie film guys, they're marketing this toward broadcasters who broadcast in 50/60p. The fact that it makes a good indie film camera is a side effect of the features that also make it a good broadcast/ENG camera.

Quote:
It simply looks filmic instead of video-ish.
You say that like "video" is a bad thing. It's not. It's just a different look for a different purpose. I don't spend all my time obsessing over how I can make my picture look like "film." I spend my time trying to shoot good-looking video. Sometimes that means the same thing, sometimes it doesn't. What you need to learn is how to respect different shooting styles than your own.
Stephan Ahonen is offline   Reply With Quote
Old December 13th, 2006, 08:28 AM   #21
Major Player
 
Join Date: Aug 2005
Location: Belgium
Posts: 497
Quote:
Originally Posted by Stephan Ahonen
And now I can't shoot properly? Funny, they keep hiring me back...
No need to take it personally - I'm sure it wasn't meant that way. All I can say is that when I first shot in 25p all action looked bad. But once I adapted to filming in 25p (instead of 50i) all things look good. Even sports. Haven't got any complaints on that one.

I'm so much accustomed to it by now, that I would only want the 50p because it gives me a super smooth full res slow motion. For all other shooting, 25p is fine for me.

I shoot a lot of handheld ENG-style - sports too, but I'm not missing the 50i higher temporal resolution. The only thing that bugs me with the HD101 is that while shooting you see 50p in the viewfinder, instead of 25p as it is recorded. Furthermore you just need to accustome yourself with the style of shooting 'low-framerate' progressive. Only slow pans or very fast ones. Perferrably following a subject while panning or making high impact camera moves, ... that sort of thing. If you're used to that, shooting sports in 25p will look just fine.
__________________
High-Definition Video Consultant - CEO of Delimex NV - http://www.delimex.be
gear of choice : http://www.wespgear.com
Werner Wesp is offline   Reply With Quote
Old December 13th, 2006, 10:39 PM   #22
Major Player
 
Join Date: Apr 2005
Posts: 512
I don't deny that 25/30p can look good when done properly. My argument for using 50/60p is that if you have a camera that's capable of it and your footage is going to be airing in a 50/60p broadcast, it's really a waste to not use that capability, especially when 25/30p footage is going to look noticably jerkier when shown next to 50/60p footage in the same broadcast.
Stephan Ahonen is offline   Reply With Quote
Old December 15th, 2006, 06:53 AM   #23
Tourist
 
Join Date: Jul 2006
Location: Amsterdam Holland
Posts: 4
Now they can broadcast 25p, they say it has nothing to do with the PAL system we have here.
Marijn Schuurmans is offline   Reply With Quote
Old December 15th, 2006, 12:20 PM   #24
Wrangler
 
Join Date: Aug 2005
Location: Toronto, ON, Canada
Posts: 3,637
Quote:
Originally Posted by Marijn Schuurmans
Now they can broadcast 25p, they say it has nothing to do with the PAL system we have here.
In the world of standard def broadcast there is only PAL/SECAM and NTSC. 25P, 30P, 24P do not exist as broadcast formats. DV 25P really only refers to the acquisition format of the material.

When you look at the tape on a technical level for broadcast it is still 50i but those two fields just happen to have been captured at the exact same moment in time - not 1/50th of a second apart from each other.

The same is true for 30P in the NTSC broadcast areas. The only exception is 24P which uses 2:3 pulldown to spread the 24 progressive frames over 1 second and make up the 59.94 fields per second.
__________________
Tim Dashwood
Tim Dashwood is offline   Reply With Quote
Old December 15th, 2006, 05:40 PM   #25
Major Player
 
Join Date: Apr 2005
Posts: 512
The ATSC digital broadcasting standard allows for 24p and 30p framerates (as well as "NTSCized" equivalents like 23.976 and 29.97). In practice broadcasters are still using the old NTSC field rates and using pulldown to show 24p and 30p content, but the capability is there in the standard.
Stephan Ahonen is offline   Reply With Quote
Old December 15th, 2006, 10:01 PM   #26
Trustee
 
Join Date: Aug 2003
Location: Vancouver BC Canada
Posts: 1,315
Quote:
Originally Posted by Tim Dashwood
When you look at the tape on a technical level for broadcast it is still 50i but those two fields just happen to have been captured at the exact same moment in time - not 1/50th of a second apart from each other.

The same is true for 30P in the NTSC broadcast areas. The only exception is 24P which uses 2:3 pulldown to spread the 24 progressive frames over 1 second and make up the 59.94 fields per second.
I think Tim has summed it up quite well here. Well said Tim.
__________________
Damnit Jim, I'm a film maker not a sysytems tech.
Ken Hodson is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > JVC ProHD & MPEG2 Camera Systems > JVC GY-HD Series Camera Systems

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 10:28 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network