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720/25p native or 1080i/25p to 35mm?


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#1 alberto borque

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Posted 30 September 2006 - 10:49 PM

Hello!
I am preparing a shortfilm with the hvx200 that will be blowed up to 35 and I have an existencial doubt: 720/25pnative or 1080i/25p?
I don't have the possibility to make a blow up test so i want to now if there are any difference. In an HD monitor the differences between 720 and 1080 are very small. Many people say that is no difference.The thing is the 720/25pnative works with the real progressive frames. On the other hand the 1080i/25p has more definition but works in progressive frames based on interlaced frames. So my question is: Is better to work with less definition but real progressive frames? or I need a big frame altough don't come from progressive?

Thank you very much and sorry for my "indian" english

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#2 Rich Steel

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Posted 01 October 2006 - 04:53 AM

Common sense would dictate that more definition/resolution would be the best way to go, No?
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#3 Gunleik Groven

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Posted 01 October 2006 - 05:14 AM

Hello!
I am preparing a shortfilm with the hvx200 that will be blowed up to 35 and I have an existencial doubt: 720/25pnative or 1080i/25p?
I don't have the possibility to make a blow up test so i want to now if there are any difference. In an HD monitor the differences between 720 and 1080 are very small. Many people say that is no difference.The thing is the 720/25pnative works with the real progressive frames. On the other hand the 1080i/25p has more definition but works in progressive frames based on interlaced frames. So my question is: Is better to work with less definition but real progressive frames? or I need a big frame altough don't come from progressive?

Thank you very much and sorry for my "indian" english

boRk


No Doubt:
Go with 1080p 25.
At least if you have a PAL camera.

1080 psf 25 is progressive. Do not think othervise. It only uses the interlace stream to deliver the progressive image. The HVX is natively doing all internal prosessing at 1920 x 1080 progressive.

If you're editing in fcp, just remeber to set the field dominance to "none" in the sequence preset, and you'll be good to go.

That said:
I've been a/b'ing some with my PAL camera after the FCP update with 720p 25 came along, and I've been very surprised of how bad 720 holds up against 1080 on the HVX. I was expecting it to be on par, given the cameras native rez, but it is not.
I thimk this could be due to the higher horisontal rez of the PAL dialect of DVCPRO HD. 1440 (euro/pal) vs 1280 (US/NTSC) horizontal lines in the 1080 image.


I'll only use 720 for slo-mo and see to that I make images that scale well.


Also I have a hard time finding a satisfactory way to monitor the 720 footage through my Decklink card.


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#4 David Beier

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Posted 08 October 2006 - 11:53 PM

Well, the native chip size isn't as much as a limiting factor as one would think since the spatial offset of the CCDs theoreticall provides 1.5 times extra resolved detail for a 1440x810 image. Also, all processing is done at 1920x1080 before being downrezzed. In Barry Green's tests, he says he's seen about 25% more detail in 1080p. For me, it has varied. I've done some tests where I can't see much of anything and others where I see about 20-25% more detail. It really depends on what you're shooting and what the lense is at (each lense has a sweet spot). At best, I've seen 25% more detail. Now, NTSC only has a sampling size of 1280x1080 for 1080p vs the 1440x1080 of PAL so you may see almost 30% more detail there. Once again though, it depends a lot on what you are shooting. I've seen some tests where the 720p is indentical to the 1080p. I suggest that you go ahead, do some tests of the type of shots you are planning in both modes, and then go ahead and export some frames as uncompressed TIFFs and look at them very close. Try uprezzing both to 4k resolution to get an idea of what you might get on a big screen.
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#5 Rodrigo Llano

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Posted 02 January 2007 - 07:38 AM

"1080 psf 25 is progressive"
sorry Gunleik but any resolution at "PSF" IS NOT progressive is based in Interlaced images.
PSF means Progressive Simulated Frames and is the technology used by many manufacturers including Sony to get "progressives" images from a Interlaced capture.

Respectfully

Rodrigo Llano
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