ISO setting for Phantom HD

[Kei Yokokawa]

Dear everyone.

 

I recently had a chance to see Phantom HD camera. The ISO rating for the camera is officially said to be ISO 600 under the sun and it changes in different wave length situations,,ie Cloudy day, tungsten light,,,,.

 

I personally wanted to see what is its ISO rating for the starting point for DPs. I initially used a chart consists of black , white and 18% gray. Set my meter to ISO 600 and the shutter angle of Phantom is set to 360 degrees. A histogram chart on PC was the guide for adjusting the lens apature as well as a wave form monitor. After a quite few comparison, I came up with ISO 200 instead of ISO 600 under both tungsten lighting and sun. I did not have a chance to take a shot of the gray card taken into a post house, so this test was not 100% accurate.

I was surprised with this result and I questioned myself if I did this test correctly.

 

I would like to ask DPs who has had experience with Phantom HD, how they set the meter.

 

Thank you

[Mitch Gross]

This opens up the dirty little secret that sensitivity as measured by the International Standards Organization (ISO) has very little to do with how you & I measure it using something like an 18% gray card or an incident light meter. Sensitivity as defined by ISO is based on the saturation point and it's relationship to the exposure range. Sensitivity based on how most of us measure it is about where middle gray falls. Your measurements are essentially correct, although I would put it more at 320 instead of 200. That is because the Phantom HD has a nice low noise floor so you can dig further into the shadows while avoiding the clipping point of overexposure.

[Kei Yokokawa]

Thanks, Mitch for your reply. My understanding of how HD lighting should be is very limited as I have been raised in a celluloid industry.

When using Phantom, you would have nothing to rely on in terms of colour and contrast ratio ,, ie the image on a monitor is not what you get as it does not show the actual raw file image. ( If you record HD/SDI image on to tape, the image on the monitor will be what the outcome .)

What you can really rely on is the histogram chart comes up on the pc screen and the best you could do with it is to put the image within its range.

 

Would "Play safe and let every adjustment be done in post" be the word for HD shoot ?

[Mitch Gross]

The HD-SDI is a fairly accurate guide for exposure, with the knowledge that you have a bi of extra room to play with in post.

[R Dee Deepak]

Im dp from india..im using phantom hd gold...shooting in indoor set, wht is my camera iso ? And how to set meter for lighting