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Old March 4th, 2006, 09:06 PM   #1
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16:9 / 480 miniDV question

I'm curious on something. I'm doing some testing on shooting in the 480 miniDV mode, and to get 16:9 i have to set to "stretched" mode. Is this doing what the old DVX did, taking a 4:3 aspect and actually lowering quality of the image to fake 16:9? I have checked the manuals and it doesn't mention, but just tells the basic common sense of what its doing but not the tech and doesn't say if you are loosing quality. My assumptions are the camera is a 16:9 camera, so you are not loosing quality, and that stretched mode is actually fine. Anyone help me with some knowledge on this?
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Old March 4th, 2006, 09:12 PM   #2
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All 16:9 DV is "anamorphic" meaning that it's squashed horizonally to fit into a 720x480 frame. When you play it back, the display device needs to "understand" that the video must be stretched back into the proper 16:9 proportions.

The only time you lose quality is when your camera doesn't have enough pixels on the CCD to give you the full 480 vertical lines. For example, the DVX-100 could only create 16:9 by chopping off the top and bottom of a 4:3 image, which only results in about 360 vertical lines. I don't know anything about the HVX, but would assume that it's capturing "real" 16:9 due to the HD sensors.
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Old March 4th, 2006, 09:12 PM   #3
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I don't have any knowledge about shooting in that exact setup, however what I'd suggest doing is that why not just shoot in any HD codec, keep the better color space and native 16:9 aspect ratio and just down-convert for your output?

However, if you don't have any P2 or the ability to output to a PowerBook via Firewire, then I understand the need for going to tape.
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Old March 4th, 2006, 09:16 PM   #4
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I assume you're talking about shooting with the HVX onto a miniDV tape. Regardless of the shape of the CCDs in the HVX, the CCDs can certainly resolve a 720x480 image, shooting 16:9.
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Old March 4th, 2006, 09:28 PM   #5
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Nice. Yeah im curious now. You mentioned the just filiming in HD then dubdown to tape. Do you think the colors/quality would be stronger when doing this then just working in miniDV in the first place? It seems a bit of a mystery to me, since its still going to tape,. im curious how much quality is kept. The final output of all my work is still sd formats, so loosing the HD res on dubbing down dosnt concern me. IM just curious if filming first in HD is actually going to get much better results even when still put down to tape.

On the leterbox mode, that seems like junk. Becuase that does just take a 4:3 and bar it. But the 16:9 ("squeezed") seems to actually be getting more in the picture. I do have a 4g P2 card, but im going to be doing alot of free running filming in thailand next month, and im curious how much of a burden having only one p2 card will be (dumping to powerbook every 10 mins). Thus im trying to get the miniDV setup figuired out in the best fashion before hand.
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Old March 4th, 2006, 09:42 PM   #6
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It's always been a known fact, that shooting in any better-than-DV25 (the miniDV standard) and then downconverting to SD results in a better output.

Without bowling you over with tons of info (although check out this website; it has a superb overview of ALL the video standards and even shows comparisons: www.adamwilt.com), here's the nutshell version:

All the digital video formats, DV25 (miniDV) DVCPRO-50, DVCPRO-HD, HDV, DVCAM etc, are compressed, and DV25 is compressed the most. When you take that project footage and then import it into any DVD authoring program it gets compressed again. All the DVCPRO codecs have much less compression, so they lend themselves to being re-compressed for DVD authoring much better.

What medium the signal gets recorded onto has nothing to do with its quality. The most expensive HD cameras on the market that cost $60k and up use tape - just not miniDV tape.

Basically it's the tried-and-true rule of thumb: Shoot in the best codec you can afford. This gives you the most options for output now, and in the future.
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Old March 4th, 2006, 09:46 PM   #7
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Cool..but when you dub down to tape does it get compressed again, or is it only changing the res? Or is shooting in minidv compressed before it hits tape? Maybe I have misunderstood this for along time, hehe.
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Old March 4th, 2006, 09:49 PM   #8
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In all honesty, myself and others could spend pages giving you all the background you really need to understand this.

I suggest taking a look at the Adam Wilt website; it's a quick read, it has diagrams and direct video format comparisons to look at and describes topics like this in an easy to understand format.

Spend 10 minutes on that site and I guarantee you'll come away with several "ah-HA!" moments.
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Old March 4th, 2006, 10:05 PM   #9
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Yeah read over the site a bit, some new things in there. So im assuming your compressing it twice by dubbing down to tape, so maybe not best idea...
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Old March 4th, 2006, 10:16 PM   #10
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I'm not sure where the second compression thing comes in exactly, but it's the amount of compression that it would get. HDV is the only HD format that is designed to go onto miniDV tape. If this is a workflow that's really important to you then maybe an H1, Z1, or HD100 would be a better camera for you. (?) I'm a bit lost as to why using tape is important if you already have the HVX?.
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Old March 4th, 2006, 10:28 PM   #11
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I have the camera, for the ability to do both, hd and minidv. I mentioned above, im going to be doing alot of on the fly shooting...so sometimes i dont have the time or convienence to just keep dumping to a powerbook, sometimes wont even have the powerbook on me. So im looking at trying to get the best picture I can, using the minidv tape ability. I know you cant film hd to dv tape on this panny, but you can dub down. Im concerned if you dub down, are you compressing the photage twice (fist with DVCPRO then DV)? I do stagged shooting, thus why i love the HD option, but also stuff on the fly-documentary styles and in tight situations, why I still love the miniDV option...
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Old March 5th, 2006, 02:25 AM   #12
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Quote:
Originally Posted by Michael Paul Young
I'm curious on something. I'm doing some testing on shooting in the 480 miniDV mode, and to get 16:9 i have to set to "stretched" mode. Is this doing what the old DVX did, taking a 4:3 aspect and actually lowering quality of the image to fake 16:9?
This confusion is due to an unfortunate naming choice on Panasonic's part.

On the DVX they had a 4:3 camera which (when put into 16:9 mode) digitally stretched the central 75% of the CCD to create "squeeze" mode.

On the HVX it's a native 16:9 camera which delivers full native 16:9 resolution. But, unfortunately, they also chose to name it "squeeze" mode.

So the name is the same, but the process is exactly the opposite. That's why I consider it unfortunate that they chose that name, as it prejudices DVX owners to think of it as a "lesser" mode, when in fact it is the far superior mode. I wish they would have named it "widescreen" mode instead.

Have no fear, "squeeze" is true pure high-res 16:9.
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Old March 5th, 2006, 02:33 AM   #13
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Quote:
Originally Posted by Michael Younger
You mentioned the just filiming in HD then dubdown to tape. Do you think the colors/quality would be stronger when doing this then just working in miniDV in the first place? .... IM just curious if filming first in HD is actually going to get much better results even when still put down to tape.
It does not. HD downconverted in the camera to DV doesn't retain the same level of sharpness & detail that straight DV in the camera does. I know people will tell you it does based on theory, but the theory simply doesn't hold up in practice.

I took a DVX100B, and an HVX in DV mode, and an HVX in 720p mode and dubbed down to DV in-camera, and an HVX in 1080 mode and dubbed down to DV in-camera, and shot the exact same frame, and made a composite JPG of the results (here: http://www.icexpo.com/HVX200/Composite.jpg)
I think it's easy to see that the 16:9 DV of the HVX looks better, sharper and clearer than the "squeeze" DV from the DVX. However, the downrezzed-from-HD isn't as sharp & clear as the straight DV from the HVX. And DV50 mode spanks 'em both.

Now -- if you want to downrez outside the camera, in your NLE, you can attain better results because you won't be re-compressing to DV. If you're going for a DVD transfer you'll get best results (IMO) from shooting DV50, and you can get extremely similar results from shooting HD and downrezzing (in post, not in-camera). But the in-camera downrezzing, while working rather well, certainly doesn't beat shooting straight DV in the first place. If you're looking for DV, just shoot DV, don't try to shoot HD and downrez to DV thinking you'll get better quality, because you won't.

Quote:
I do have a 4g P2 card, but im going to be doing alot of free running filming in thailand next month, and im curious how much of a burden having only one p2 card will be (dumping to powerbook every 10 mins). Thus im trying to get the miniDV setup figuired out in the best fashion before hand.
If you're shooting DV, you'll get 16 minutes of footage on that 4GB card. I'd recommend shooting DV50 if at all possible, since it looks so much better, but that would only give you 8 minutes.

Regarding offloading with only one card -- I strongly, strongly, strongly (did I say "strongly"?) recommend having two cards. With one you have to stop production while you offload (unless you want to switch to DV tape during the downtime, I guess.) With two cards you'll never be left waiting, you can shoot continuously and constantly, and the Powerbook will always be ready with a fresh empty card before you need to swap. It makes life with P2 so much easier to have two cards.

Good luck!
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Old March 5th, 2006, 03:07 AM   #14
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Perhaps replacing the HVX with an HDV camera would be a viable option? I would think that would be a generally superior approach for getting high quality acquisition, in all situations essentially, since you are "often" unable to use the P2 cards in the HVX (and would be less expensive).
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Old March 5th, 2006, 03:25 PM   #15
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Barry thank you so much for all that info, you hit what I was rwally trying to find. Yeah im debating shooting the 480/24p with DVCPRO and getting 16 mins of photage on the P2 card. Then dumping that real quick and keep rolling away. I hear you on the two cards, but budget wise, im trying not to jump on buying to many of these early 4 gig cards. Id rather wait a year, make due with jerry riggin my setup and then when the tech prices drop and bigger cards exist then I will buy a second card. Im debating just getting an external drive to dump to on the fly instead of having to have the powerbook up the whole time. Like I mentioned being on the fly next month, sometims hiking trails, id rather dump to the hard drive and at night come back and backup most the stuff to DVD or during a lunch break, etc on the PB.
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