underexposure

Daniel Madsen · May 5, 2006

My friend found all the film he shot under fluorescents (the exterior shots were fine) to be two stops underexposed. Could this be a problem with the light meter he was using? Under what lighting condition do meters become unreliable?

Jamie Metzger · May 5, 2006

There are so many variables involved. I thought a camera my friend let me use had an UV filter on it, and it turned out to be an ND 1.2; making it 4 stops under.

His FPS could have gotten bumped up to 48 or 64 or 96, or his ISO speed could have gotten bumped up higher as well. The digital meters slip all the time with the passing of hands. It's usually operator error.

Maybe the 1st left an Nd .6 in the tray from shooting outdoors?

Laurent Andrieux · May 5, 2006

My friend found all the film he shot under fluorescents (the exterior shots were fine) to be two stops underexposed. Could this be a problem with the light meter he was using? Under what lighting condition do meters become unreliable?

This problem may be due to the way the metering was done or a wrong sensitivity computed in the meter.

What stock or camera if video, was it shot with ?

About the way it's metered : one has to be very carefull with counter lights (back lights). One should protect the meter from these light with his hands for metering.

Another point is where you meter. Was the caracter where you metered, or did you meter closer to the lights than the caracter is ?

my friend let me use had an UV filter on it, and it turned out to be an ND 1.2; making it 4 stops under.

I don't believe a UV filter that cuts some much light. It cannot be a UV filter alone.

Matt Sandstrom · May 5, 2006

I don't believe a UV filter that cuts some much light. It cannot be a UV filter alone.

it wasn't. it was an nd. he *thought* it was a uv. at least that's how i read it.

/matt

Laurent Andrieux · May 5, 2006

Ok sorry - language missunderstanding - thought you ment "the UV filter was acting like a ND 1.2" while you ment "TWhat my friend thought was a UV filter was actually a ND 1.2" if I get I right.

Andy Sparaco SOC · May 5, 2006

My friend found all the film he shot under fluorescents (the exterior shots were fine) to be two stops underexposed. Could this be a problem with the light meter he was using? Under what lighting condition do meters become unreliable?

1) Meters indeed become unreliable after the 15th hour of a 16 hour production day

2) After six beers after a 16 hour shooting day

3) After a 6 hour turn after six beers after a 16 hour shooting day.

Also beware the light green tape applied to a mag which denotes 52/7201 will turn light blue like 52/7205 under Flourescent lights resulting in two stops under exposure....abetted by the 6 hour turn bla bla

william koon · May 7, 2006

1) Meters indeed become unreliable after the 15th hour of a 16 hour production day
2) After six beers after a 16 hour shooting day

3) After a 6 hour turn after six beers after a 16 hour shooting day.

Also beware the light green tape applied to a mag which denotes 52/7201 will turn light blue like 52/7205 under Flourescent lights resulting in two stops under exposure....abetted by the 6 hour turn bla bla

Can these make sense ? Somebody please help to explain further. I m afraid that these 3 explainations were written after hte 6 + 6 beers. Or we have to change meters every 16th hr. thanks.

Laurent Andrieux · May 7, 2006

Well, it's clear to me ! After 16 hours, we have to change... day ! (and then have another couple of beers !)

Chris Pritzlaff · May 9, 2006

1) Meters indeed become unreliable after the 15th hour of a 16 hour production day
2) After six beers after a 16 hour shooting day

3) After a 6 hour turn after six beers after a 16 hour shooting day.

You forgot Number 4

4 After a 16hour day with a 16 hour day before with a 6hour turnaround and 6 beers between the two. THe light meter will be completly wrong and is only readable after 6 more beers are consumed. :)