DVL-Digest 854 - Postings: Index ISO equivalent of videocamera (I know, it gets boring) ISO equivalent of videocamera ... Matrox RT Mac - The Whole Story What if.... ISO equivalent of videocamera (I know, it gets boring) - Adam Wilt [context: metering off an 18% neutral gray card] > The only thing I'm sure of with just a camera (sans WFM) is the zebra > is 80-90 IRE. So if I adjust the camera so one thing has zebra > stripes, then I meter off that thing and adjust it it ?? stops higher > and adjust ISO it should work. Right? First, most DV cameras have zebra at 100 IRE, with some switchable to 70 IRE. Second, use auto-aperture. When the exposure has stabilized, push the status button or the aperture lock and read off the iris setting. The whole point of the neutral gray card is that it's a perceptually "average" brightness. The camera's iris should be correct when shooting a gray card full-screen. Once you've got an objective calibration of this sort, don't be afraid to tweak it for lighter or darker renderings. Many film DPs use the published ISO rating of a stock as a starting point to develop their own personal ISO rating for it, finding they get more pleasing results with some degree of nominal overexposure or underexposure. You may also find that, over time, you change your personal ISO rating as you develop more exerience in exposing pictures, or as you develop your own "look." Cheers, Adam Wilt ISO equivalent of videocamera ... - "Perry" > The only thing I'm sure of with just a camera (sans WFM) is > the zebra is 80-90 IRE. The original Zebra was on (Japanese) broadcast cameras, and intended to indicate well exposed face tones. With Japanese faces this was typically 70%. FWIW I always set my Zebra to 100% if adjustable. Using grey scale value to find equivalent exposure between film and video is fraught with problems of dissimilar transfer curves (gamma). As I said before, you can only get a very approximate equivalence or a range of ISO values. Perry Mitchell Video Consultant http://www.perrybits.co.uk Matrox RT Mac - The Whole Story - Adam Wilt > ]And with this card the question arises: what codec would be better, the > >Apple QT 5 or the C-Cube DV 25 ? The Apple codec is better. C-Cube tends to show more chroma errors on sharp transitions after a few generations. Cheers, Adam Wilt What if.... - Adam Wilt Is working in PAL (for NTSC folks) that difficult? Yes, for many it is. > -- Sony has the DSR-11 which will work in DVCAM in either format... And a very nice deck it is, too. > -- All NLE's (that I know of) will swallow both PAL and NTSC through > the firewire... Many if not most of those sold in the USA, especially those at the low end, are shipped as NTSC-only NLEs and lack the PAL codec. > -- If you're going to buy a new camera anyway and one who's purpose is > digital cinema then you might as well get a PAL camera "off the rack"... Yes, for those with trust funds or windfall profits from the dotcom bubble, buying a PAL camera (and PAL-capable monitors, VTRs, and NLEs) solely for digital cinema is an option. But lots of people need to get gear that helps 'em pay the bills -- try getting a commercial, corporate, or broadcast gig in this country with PAL gear, and people look at you funny! How do you hand off VHS copies for review, approvals, scoring, etc.? Do you do a PAL/NTSC standards conversion every time? Or must all your recipients have PAL playback capability? How do you handle the 4% speed change when working with a composer? There's a lot more format-dependent production infrastructure that comes into play beyond the cameras. > ...and take advantage of the extra vertical lines, That is PAL's biggest advantage, I grant you that. > ...better color gamut... Does PAL have that much better a gamut? In any case, a 24p/varispeed DC (digital cinema) camera should incorporate an extended red response like the F900 or HD27V, with a matrixing switch to revert back to standard colorimetry for use in "normal television" production. > ...and "film look" frame rate. It doesn't get any more "film look" than 24fps! Granted, with a bit of work a true PAL DC camera could be made: use a proscan chip, segmented-field recording (as the XL1/XM1 nearly do already), and a 16x9 CCD with extended-red matrixing. But in NTSC-land, you'd still need all the other components of a production system to work in PAL. And there's still the 4% speed change, which bothers some folks all out of proportion. Still, in PAL countries, this would be the ideal working tool for those who can't afford HD. In NTSC-land, a DC camera capturing 24p, writing to tape as bog-standard 60i NTSC with 3:2 pulldown, lets you use existing NTSC-aware NLEs, monitors, VHS decks, and the like. [BTW I'm not proposing a switchable 50i/60i camera -- since there is no common image format between NTSC and PAL, the CCDs are incompatible between formats (PAL has 20% more lines, and the scanlines on a PAL chip are 20% narrower as a result) and there's a corresponding 20% difference in per-frame data size.] Cheers, Adam Wilt (diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-) [up] |
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