Lighting

[Janusz Sikora]

Andy…

You are correct ! 🙂

Provided your video camera is calibrated for correct value of the ASA/ISO equivalent (there are methods to obtain that value).

With your hypothetical example at given ASA value, Incident at 2.8 and Lens at 2.8 will/should produce Middle Grey – IRA 50. Everything else will show like what it is in terms of IRA… so the face of the subject (depending on skin tone) – you can preasume – will show at around IRA 60 (average caucassian – Zone VI/IRA 65/70). And yes… if you want to know exact value of the face, you need to Spotread it 🙂
So you can easily imagine that creative approach is about “dancing around” F.28 where you set and control values aroud it (IRA 50)to your liking, keeping in mind latitude of the medium )

janusz
https://www.lightextreme.com

*It’s quite about Light*

[Janusz Sikora]

Andy, you are correct 🙂

Provided your Video Cam is calibrated for correct ASA equivalent (there are methods to obtain this value) – your Incident 2.8 with the cam lens at 2.8 will maintain Ira 50 at the middle of the scale.
Everything else will reproduce as what it is… Caucassian face will show at around Zone VI – 60/70 IRA (depending on the skin tone).
Yes, if you want to know the exact value, you will need to Spot read it. You can easily see how “dancing around Grey” will give you creative control over the look/mood you intend to create…
What remaims is to watch you staying within latitude of the medium (Spot Meter).

janusz
https://www.lightextreme.com

*It’s quite about Light*