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ISO equivalent for Studio Camera HD?

PostPosted: Thu May 10, 2018 10:10 pm
by Hadmut Danisch
Hi,

the Studio Camera HD doesn't tell it's sensivity in ISO equivalent, neither the menu nor the manual, just comes with some default sensitivity and a gain parameter in 6db steps.

What would be the ISO equivalent to use a regular (cine-) lightmeter to check for proper light?

(And, btw., is there a particular reason to not use common ISO values?)

regards
Hadmut

Re: ISO equivalent for Studio Camera HD?

PostPosted: Fri May 11, 2018 5:06 am
by Denny Smith
Studio and ENG Broadcast cameras used actual analog Gain to set the sensor sensitivity. A wave form Monitor is used to set base exposure and a light meter used to set lighting ratios. Cinema cameras, being film based, used ASA/ ISO film ratings, so a light meter was used to determine proper base exposure, so ISO settings are used on digital Cinema cameras, but false color and wave form monitors are still a more accurate way to set exposure and check for sensor clipping, along with Zebra displays on a monitor.

Meters are great for setting lighting ratios between key and fill lights. The “0” Gain on a BM Studio Camera 4K is around ISO 200, +6 would be 400, etc. However, adding gain can increase the background noise level in a sensor. That said, I find 0 and +6dB gain acceptable on the Micro Studio Camera 4K. The HD Camera is the same sensor, but processed a little differently, as the Picket camera which has a native ISO level if 800, and sound be good up to +12dB. A little experimenting on your part can show what is the best setting for yiur lighting situation.
Cheers.

Re: ISO equivalent for Studio Camera HD?

PostPosted: Sun Nov 04, 2018 2:04 am
by srdjanb
Meters are also a great and a fast(er) way to light a studio set without the need for a camera controll technician and all cameras present on the set with cameraman behind them (think of the 8-12 camera set-ups and the time and money saved). And that is why the iso (asa) rating of the cameras is vital since all meters are calbrated that way.

Some of the manufacturers omit the iso ekvivalents for the marketing reasons since 200 iso, for example, requires 2.5x the light than average studio cameras - that means bigger and more lighting fixtures and more power consumption. When you are talking about the show that airs everyday all year around, that amounts to a lot of money.

If you are still using the "hot" tungsten lights the climatizaton is a factor also.

Re: ISO equivalent for Studio Camera HD?

PostPosted: Tue Nov 06, 2018 7:29 pm
by Denny Smith
A better way is to setup all the cameras on a waveform monitor and white balance them using a Vector Scope. Much more accurate than a light meter. Thst said, the light meter does have its o,ace in lighting the set, and getting lighting ratios set on the studio lights.
Cheers

Re: ISO equivalent for Studio Camera HD?

PostPosted: Wed Nov 07, 2018 9:39 am
by srdjanb
The only way is to set the cameras using waveform and vectorscope, probably with gamma chart and colorchart.

But the most effective way to light the scene is with lightmeter, incident AND reflected (spot), especially if you have a lot of leds in background.

This way you eliminate the unnecessary crowd on the set, need to run to and from the controll room, etc.. and, as I said before, if you know the ISO rating of the cameras your using, you can set the lights to desired f stop easier (desired f stop being around 4 ;)) .

But you are right, without the waveform monitor and vectorscope you cannot set the multiple cameras properly.

Cheers,
Srdjan Bozinovic
DoP & Chief Cameraman

Re: ISO equivalent for Studio Camera HD?

PostPosted: Thu Nov 08, 2018 4:43 am
by Denny Smith
I completely agree with you, nice summary.
Cheers