Measuring exposure for a beginner?

[stanw]

1.) Is there an easy way for a beginner like myself to measure the exposure on a green screen and on the subject? OR is a light meter really the only way to do this?

2.) I read somewhere that the subject's face should be around 60ire and the greeen screen at around 40ire. Are "ire" values the exposure settings that a light meter would indicate?

Thank you.

 

[Tabula Rasa Productions]

use zebra stripes if you have them! what camera do you have?

 

[stanw]

the HVX. how would you do this with zebras?

 

[salils]

the HVX. how would you do this with zebras?

Hit the "zebra" button on your camera inside the LCD. It will show diagnol zebra stripes that correlates to a specific IRE value that you set. You can change what IRE level it displays by going into the main menu > Display set-up > Zebra
I've found around 70%-80% IRE is good for lighting your screen at.

 

[stanw]

Thanks Salils. I will try that. I just borrowed a Sekonic L-398A and have no idea how to use it and it does not have a manual. Is there an easy way for me to learn to use just enough about the features of this device to measure the exposure of the subject and the screen?

 

[salils]

Thanks Salils. I will try that. I just borrowed a Sekonic L-398A and have no idea how to use it and it does not have a manual. Is there an easy way for me to learn to use just enough about the features of this device to measure the exposure of the subject and the screen?

Light meters aren't very useful for setting exposure on video, unlike film cameras video cameras do not have an ASA rating. Even if you were to find this out using a 55 gray card, it wouldn't be highly accurate because the ASA actually changes a bit on different f-stops. Light meters are good if you want to keep track of a consistent look and contrast ratios...but not so much for setting the camera's exposure.

 

[stanw]

Hi salils,

Being so new to all of this, I could be using the wrong terminology here. What I want to do is make sure that there is:

a) a consistent look across the green scree, to ensure that it is evenly lit
b) make sure that the subject is lit in a similar way (not exactly the same though) to the green screen.

Will a light meter assist me with this?

Light meters aren't very useful for setting exposure on video, unlike film cameras video cameras do not have an ASA rating. Even if you were to find this out using a 55 gray card, it wouldn't be highly accurate because the ASA actually changes a bit on different f-stops. Light meters are good if you want to keep track of a consistent look and contrast ratios...but not so much for setting the camera's exposure.

 

[Tabula Rasa Productions]

there is this spot exposure thing built into the hvx and the dvx, you get to it by pressing the zebra button 3 times i believe

 

[salils]

Hi salils,

Being so new to all of this, I could be using the wrong terminology here. What I want to do is make sure that there is:

a) a consistent look across the green scree, to ensure that it is evenly lit
b) make sure that the subject is lit in a similar way (not exactly the same though) to the green screen.

Will a light meter assist me with this?

If you see the zebra pattern covering the entire screen and then close the iris about 1/2 stop and the zebras disappear on the green screen entirely then your screen is probably reasonably lit. You don't need a light meter for this. Where a light meter might be handy is if you shot two over the shoulder shots that you wanted to match, you would want to make sure the same amount of light and/or contrast is on both of the subjects.