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-   -   One thing I don't understand (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/97516-one-thing-i-dont-understand.html)

Juni Zhao June 25th, 2007 06:13 PM

One thing I don't understand
 
I read that JVC GY-110/200 is designed and made for 24p and most favored by filmmakers who inverse telecine the footage to 35 mm film. But I know this camera is HDV-1 standard which is 720 vertical pixels, much less resolution than 1080. Why that much reduction in resolution can make this camera be best for filmmaking?

Phil Balsdon June 25th, 2007 07:08 PM

The JVC camera records in progressive scan, similar to the way a film camera records the image to a film frame. This means you see all 720 lines every frame.
The Sony and Canon cameras use interlaced frames, which means at any given moment you a field 540 lines which is very closely followed by the second field of the 540 interlaced lines to make up a frame. This system is used by television for more efficient transmission purposes.
Progressive scan is necessary for a film out transfer so this makes the progressive scan of JVC (Panasonic HVX200) cameras ideal. Progressive scan images are easily converted to interlace for transmission purposes. Converting interlace to progressive is not so simple and in camera options are very much a compromise.
Most modern flat screen monitors (LCD or Plasma), computer monitors and digital video projectors are natively progressive scan, so also suited to the progressive frame system.
It's difficult to see a difference in resolution with your eye when viewing the two different formats. If you intend to shoot mainly for television transmission interlace is probably a better choice, for film out or "film-look" then progressive would be a more suitable choice.

Phil Balsdon
http://www.steadi-onfilms.com.au

Juni Zhao June 25th, 2007 07:40 PM

Thank you so much Phil. I know Canon H1 and most other handheld cameras are capable of 24p. Do they still retain 1080 resolution when in 24 progressive? Does the res drop to 720 when in 24p mode? Why these cameras are not favored by filmmakers?
Sorry for so many questions in a single post :-)

Pete Costanzo June 25th, 2007 09:33 PM

Well, first, you're on the JVC Pro HD board, so on this board JVC is favored by film makers. If you go the Canon board, you'll get a different story :) But read the Canon specs those cameras are not outputting 24p, they're outputting 24f (fields), regardless of the res. As Phil noted earlier, 24f is interlaced, but there are plenty of film makers using the H1, so there's no magic camera, it's a matter of preference and money. Good luck! I've heard the Canon H1 puts out a pretty sharp picture, but with the JVC you get the optional native PL mount lens adapter and the flip screen option, which you don't get *from Canon* without going to some of the other vendors. With 5K I can't see not buying an HD110. With 10k, I'm not convinced JVC has the market, it's tough competition in that area between Canon, Panasonic HPX500 for a few thousand more..

Juni Zhao June 25th, 2007 10:37 PM

Thanks Pete, I mixed up 24f with 24p, now I got it.......

Steve Mullen June 25th, 2007 11:57 PM

Quote:

Originally Posted by Juni Zhao (Post 702721)
I read that JVC GY-110/200 is designed and made for 24p and most favored by filmmakers who inverse telecine the footage to 35 mm film.

There is no need for inverse telecine since you will be editing a 24p timeline just like film.

PS: some may consider this a "filmmakers" place to hang out, but many of us are aggressively anti-low temporal rate video and believe the BEST thing about the HD200/HD250 is finally having the ability to get adequate progressive temporal resolution. We would say shooting at anything less than 50p is like shooting low-rez DV because it reminds of the "good old days."

Just as max. spatial resolution improves the viewing experience, maximum temporal resolution is equally important. Low temporal rate capture distorts reality and the distortion is very visible and has a name -- judder. IMHO 24p should be treated like switching on "old film" or "sepia" with a consumer camcorder. Use when you want people to think "historic."

Today, viewing high quality images are no longer associated with film -- they are associated with 720p60 video they see on ESPN, FOX, and ABC. When NASA wants to see reality -- they don't shoot film. They shoot 720p60. And, in the next few years they will be shooting 1080p60.

The idea that narrative productions must be shot on film is a belief that is challanged every evening in Japan and Korea where drama is shot and viewed using 1080i60. Good drama is the story, sets, costumes, and lighting -- not 19th and 20th Century frame-rates.

In fact, one could argue that putting people in the "reality" of the situation increases emotional involvement. Why is Aliens far more scary on a huge screen than on an iPod? Why was scope and Cinerama created? Why does IMAX use high frame-rates?

PS: That doesn't mean I don't love old film. But, it's grain that works for me, not the judder because the old directors with their gear driven pans and multi-ton dollies/cranes kept it very much under control. I just don't see the point of using video cameras to try to get a film look.

But, if you do want a film look -- I'm certainly not telling you not to. That's the great thing about the JVC series -- one can choose REAL 24p/25p or REAL 50p/60p.

David Scattergood June 26th, 2007 03:20 AM

Very interesting post Steve.
So engrossed in discovering my HD100 I haven't paid too much attention to the 200/250 - didn't realise they shot at 50p (I shoot mainly in 25p) and I haven't as yet seen any 50p footage.
I'm still not entirely sure that interlaced is more 'reality' like than progressive. Interlaced has that in the moment/live studio look but sitting typing this in my room it just seems more natural and I don't think interlaced would entirely convey that?? Hard to judge mind. I know I much prefer the footage I've shot in in 25p over 50i on this camera, I just have to be very careful with the pans (elastic band on a decent tripod helps)...it's frustrating sometimes as I'll need a fast tilt/swing and you can't really get away with that in this format - would 720p50 help out on this or should I really be looking at another camera set up i.e. 1080 interlaced (such as the H1)?

I'm always interested as to what camera's and formats they use on the American shows eg NYPD blue, CSI, Law & Order, 24 - the new series brothers & sisters etc. None of these 'appear' interlaced to me but I've couldn't guess what formats they would use?

Interestingly although it's been said that sport is more suited to progressive it appears that over here at least our main broadcasters are favouring 1080i over 1080p (even though the majority of new tv sets sold now are progressive plasma/LCD panels).

Still as the numerous video's posted on these boards will contest for a camera at this price it can produce some fantastic images.

Steve - I'm going to order your handbook this week - I'm going away for a week soon and will take and 'imbibe' your book then - hopefully the UK have a similar binding service as Kinkos.
Cheers.

Steve Mullen June 26th, 2007 04:43 AM

Quote:

Originally Posted by David Scattergood (Post 702898)
I'm still not entirely sure that interlaced is more 'reality' like than progressive. Interlaced has that in the moment/live studio look but sitting typing this in my room it just seems more natural and I don't think interlaced would entirely convey that?? Hard to judge mind. I know I much prefer the footage I've shot in in 25p over 50i on this camera, I just have to be very careful with the pans (elastic band on a decent tripod helps)...it's frustrating sometimes as I'll need a fast tilt/swing and you can't really get away with that in this format

You are correct -- it's the 720p50/720p60 that captures most accurately. If you want this look, then the HD200 would be a great upgrade for you.

The BIG network shows are shot on film because they expect to have a very long life in world-wide syndication and the need for maximum possible quality.

Prime time in Japan and Korea simply have a much lower probability of syndication.

However, I'm a faithful viewer of AZN and would love if it went HD.

David Scattergood June 26th, 2007 05:34 AM

Quote:

Originally Posted by Steve Mullen (Post 702909)
You are correct -- it's the 720p50/720p60 that captures most accurately. If you want this look, then the HD200 would be a great upgrade for you.

To be honest - I haven't seen any JVC HD200 50p footage (any on here?). Wondering if it still conveyed a filmic look (though not as 'historic' as 25p).
I'd be pushed to afford another camera at the moment - not sure if i read this correctly but I understood that this camera does not come with a lens which you have to purchase on top?)

Quote:

The BIG network shows are shot on film because they expect to have a very long life in world-wide syndication and the need for maximum possible quality.

Prime time in Japan and Korea simply have a much lower probability of syndication.

However, I'm a faithful viewer of AZN and would love if it went HD.
AZN as in Asian Televsion? (don't think it quite reaches these stores) Shame as I really like Asian cinema - be interesting to check out their television - I honestly thought they were, along with the US, ahead of Europe in terms of HD broadcast?

Surprised about the shows running on film I just assumed they would now run with high quality HD video (and didn't 24 play with the idea of the JVC HD100 series?).
I don't suppose there is a great deal of difference between 24p and 25p either, in quality terms. The way I read it then is for the look of these big shows (and presumably for certain types of corporate video's) 50p would be ideal. For the specific film look then 25p is a good choice (although I've shot small corporate footage and it fits the purpose very well indeed).
I've seen very sharp, modern interlaced HD camcorders...but the image shouts 'live cooking show/live travel' etc. I'm just not keen on it at all.

Thanks Steve.

Daniel Weber June 26th, 2007 06:21 AM

Quote:

Originally Posted by David Scattergood (Post 702917)
Surprised about the shows running on film I just assumed they would now run with high quality HD video (and didn't 24 play with the idea of the JVC HD100 series?).

The TV show 24 uses the HD100 to shoot some of their backing plates. The show is still shot on Film.

Dan Weber

Jad Meouchy June 26th, 2007 01:59 PM

Steve, I agree completely. I've got an HD100 and it's amazing how many people chew me out for not shooting in 24p. Even after I explain that the per-frame quality of 30p is the same and I am simply getting more temporal resolution, they resist. Even after I explain that none of this footage will ever be transferred to film and, at worst, 24p will be poorly transcoded to a 30/60p digital projection system, they resist. 24p is a buzzword I suppose.

Do you think the hd100->hd200 step is worth it for 60p?

Juni Zhao June 26th, 2007 10:16 PM

Quote:

Originally Posted by Pete Costanzo (Post 702805)
Well, first, you're on the JVC Pro HD board, so on this board JVC is favored by film makers. If you go the Canon board, you'll get a different story :) But read the Canon specs those cameras are not outputting 24p, they're outputting 24f (fields), regardless of the res. As Phil noted earlier, 24f is interlaced, but there are plenty of film makers using the H1, so there's no magic camera, it's a matter of preference and money. Good luck! I've heard the Canon H1 puts out a pretty sharp picture, but with the JVC you get the optional native PL mount lens adapter and the flip screen option, which you don't get *from Canon* without going to some of the other vendors. With 5K I can't see not buying an HD110. With 10k, I'm not convinced JVC has the market, it's tough competition in that area between Canon, Panasonic HPX500 for a few thousand more..

Pete, can I say that when I shoot using Canon H1 or A1 in 24f mode, all I get is field, that means 540 vertical pixels each frame? That is why GY HD is superior for its 720 vertical pixels at 24p?

Chris Hurd June 26th, 2007 10:18 PM

No that's not how frame mode works. It's not 540 vertical pixels each frame.

You need to get your head around this resolution thing. That's not what makes or breaks an HD camcorder.

Chris Hurd June 26th, 2007 10:22 PM

Quote:

Originally Posted by Pete Costanzo (Post 702805)
those cameras are not outputting 24p, they're outputting 24f (fields), regardless of the res.

Incorrect. The output is indeed 24p. After all, Final Cut Pro and other major NLEs capture it as 24p.

The "f" does not stand for "fields." It stands for "frame." Hope this helps,

Chris Hurd June 26th, 2007 10:29 PM

Quote:

Originally Posted by Juni Zhao (Post 702721)
I this camera is HDV-1 standard which is 720 vertical pixels, much less resolution than 1080. Why that much reduction in resolution can make this camera be best for filmmaking?

There is no "reduction in resolution." You have to understand that 1080i and 720p are equal in bandwidth. Frames from both formats contain the same amount of information.

Phil Balsdon said it best earlier in this thread: "It's difficult to see a difference in resolution with your eye when viewing the two different formats." Hope this helps,


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