lighting question...

[richie g]

Set: In a darkened room, no interior light source, filming out a glass window with antiglare properties at a distance of about 7 feet to catch a brightly lit object. I have the iris practically closed to compensate for the brightness which in the image makes the room dark but the image outside the window bright and clear. But then I open the iris and the brightness flows in creating an overexposure of light at the window And at the same time I let in full direct sunlight from behind me and to my left yet the image in the window remains overexposed. Shouldn't the sunlight washout the overexposure in the window from the outside light source since, after all the sunlight is so much brighter than the light source out the window? Or is the overexposure from the outside source normal still? Will I need to close the iris again somewhat to reduce the overexposure effect I'm getting in the antiglare window.

 

[Paul Sorensen]

Set: In a darkened room, no interior light source, filming out a glass window with antiglare properties at a distance of about 7 feet to catch a brightly lit object. I have the iris practically closed to compensate for the brightness which in the image makes the room dark but the image outside the window bright and clear. But then I open the iris and the brightness flows in creating an overexposure of light at the window And at the same time I let in full direct sunlight from behind me and to my left yet the image in the window remains overexposed. Shouldn't the sunlight washout the overexposure in the window from the outside light source since, after all the sunlight is so much brighter than the light source out the window? Or is the overexposure from the outside source normal still? Will I need to close the iris again somewhat to reduce the overexposure effect I'm getting in the antiglare window.

Not sure what you are saying, if the room is darkened, where is the sunlight coming from? If you are saying that you opened the blinds on a window or two, remember that the light outside is still several stops brighter. You would need to be in a room with no roof or walls to get the same reading inside and out. Try this, take a reading with your camera against the wall next to the window and one looking out the window. You should see that they are several stops apart in intensity.

One reason that you are having this confusion is that our eyes are really good at managing situations like this, we can look out a window and out eyes balance the light from the outside and inside far better than film can.