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ISOs for HD


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#1 Ben Barrett

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Posted 26 November 2008 - 08:12 PM

Hey guys, I have a Sekonic light meter but I wondered what I should set the ISO number to for the correct exposure on a given camera? I'm planning to shoot on the HVX-200, but how do you work it out, or know, what it should be?

Many thanks for your help,
Ben
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#2 Adrian Sierkowski

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Posted 26 November 2008 - 09:54 PM

As said before, varies based on scene content and a lot of what you mess with in the menus. Take a grey card and exposed it to 50IRE under T lighting and D lighting. Correspond the F Stop on the lens to the same F Stop on your meter by adjusting the meter's ISO value and you'll get a rough approximate which can help when first setting up lighting. For HD video you really have to light by your histograms/vectrascopes/monitors though, so try to get em, learn em and make sure they're calibrated!

(HVX for me is about a 160 as it gets very noisy under low light in my experience)
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#3 Ben Barrett

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Posted 30 November 2008 - 07:21 PM

Thanks Adrian. I've been concerned about the light levels. I want to avoid electronic noise if possible, but the video still requires elements of darkness. I'm not sure how far the HVX-200 will let me go before it becomes too dark for it (or just plain bad lighting).

The shot I'm thinking of is outdoors and we've got no geny or power source near by. My guess is that indoors one could hang black fabric to absorb the light and use a small fresnel on the talent with a reflector to give some fill (add background practicals as needed).

I think I need some experience though, but thanks for your advice!

Ben
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#4 Alfeo Dixon

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Posted 30 November 2008 - 11:12 PM

For HD video you really have to light by your histograms/vectrascopes/monitors though, so try to get em, learn em and make sure they're calibrated!


That's a crock of sh!t (not a personal attach Adrian)... Ben if your a meter guy, then keep your meter out, It will make you a much better DP. DO your homework. By that, I mean go to the rental house and YES, put a scope up on a chart and find out where the camera your using falls with its sensor. But don't let a monitor dictate your skills while in the soup. Your meters will never fail you (unless the battery died or it's broken *grin*)

The only thing you should adjust is the train of thought of exposing for the blacks and lighting for the highlights... reverse that and expose for the highlights and light for the blacks. But know your working ratio for that camera... where the highlights go out and where the blacks fall off.

If you come from the still photography world, thing of any video SD/HD as if you where shooting transparency.
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#5 Adrian Sierkowski

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Posted 30 November 2008 - 11:20 PM

No attack taken Alfeo. However I would mention that a lot of these prosumer camera will respond differently based on scene content not to mention with the level of customization built into the camera through "picture profiles," and the like; I really find a meter less useful than I would on a comperable film shoot (though it's very nice for looking at contrast ratios and the like). for camera exposure proper I very much so stand by the necessity to look at the histogram/zebras on the camera itself, just to make sure. Now that's just me and of course a proper vectrascope would be fantastic, though not always budget-possible. Of course, there's more than one way to skin a cat ;). Also learn how to set color bars before you start judging exposure by monitors alone ;).
And treating digital like reversal/transparency is the right way to go.
There are no really hard/fast rules in film (aside from take off the lens cap) so long as you get the results the client wants, doesn't matter if you're going off of your meter or off of a histogram. (personally, though I'm a meter man myself, just havn't sadly had reason to pull it out recently {lots of eng doco shooting}).
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