Quote Originally Posted by Leave Me Here View Post
Sorry, just to clarify, I'm using a standard incident Light Meter. A Sekonic L-358.
In that case the readings will not allow an accurate prediction. You will have to do some test prints to 'calibrate' your light meter readings.

If you had something like the Horseman film plane meter, you could just hold it near the wall and read the exposure time, though, you would need to read the display from the wall side of the meter.