Red lens T-stop help

[Evolution]

I am new to shooting with the Red, just got mine a little while ago, and have only shot with "auto everything" HD pro-sumer cameras up to this point.

I am doing test shots in preparation for a client shoot next month, and really do not feel like I understand the Red lens (18-50mm lens). I understand zoom and focus obviously, but the T-stop is new territory for me.

Right now, I basically turn it until the shot "looks good" through the monitor. I don't feel as though this is the best way of approaching it, I don't understand what the numbers mean, how they are to be used in reference to the shot. I assume there is a more scientific, or at least logic approach to this.

Any help is appreciated. Specific to this lens and the Red One would be even better. I want to feel confident I am adjusting the T-stop based on facts, not just an "eye-ball" look.

To complicate matters, out first shot is on a green-screen, using a teleprompter......Thank you in advance

 

[Martin Weiss]

Turn on the histogram in your viewfinder, and make sure to expose to the right, meaning opening up the aperture as much as possible, without overexposing.

You might want to get a stills camera with a manual lens, so you can experience a bit as to how the f-stop affects the image. Basically doubling the f-stop number halves the amount of light hitting the sensor.

The lower the number, the shorter the depth of field.