exposure

[Jim Nelson]

hi,

 

I've noticed that sometimes when you light, then look through the view finder, the image looks a little darker. Other times it just appears exactly the way I see it with my eyes. Each time it was properly exposed. Can someone please tell me is it like this?

 

Obviously I know that the human eye can see in every light intensity unlike the camera.

 

 

Also why do we use such intense lights in filmmaking?

 

 

thanks

[David Mullen ASC]

hi,

 

I've noticed that sometimes when you light, then look through the view finder, the image looks a little darker. Other times it just appears exactly the way I see it with my eyes. Each time it was properly exposed. Can someone please tell me is it like this?

 

Obviously I know that the human eye can see in every light intensity unlike the camera.

 

 

Also why do we use such intense lights in filmmaking?

 

 

thanks

 

Your eyes adjust, but it's also because viewfinders are dimmer than compared to what your eye sees directly, and they get even dimmer if the lens is stopped down. If you put a zoom on the camera and it is an f/4 wide-open and then you put a prime on that opens to f/2, then the viewfinder image is going to look dimmer when the zoom is on compared to the prime IF you open the iris all the way on both lenses -- because the prime lens' iris opens more.

 

Why do you think we often use intense lights in filmmaking?

 

One reason may be because of the speed of the film stock or the frame rate / shutter speed of the camera demands higher light levels.

 

Another reason may be that you want to be able to shoot at a deeper stop.

 

Another reason is that either you are balancing your lights to something bright (like a daytime background) or that you are recreating a bright light (like recreating daylight.)

 

Also, large soft light techniques are not power efficient, you lose a lot of intensity when softening a light a lot, so you start out with a more powerful light to compensate.

[Jim Nelson]

thank you very much for your help. I understood the reason why we use very intense lights but I'm sorry didn't really understand exactly why sometimes what I see through my eyes is exactly the same as what I see through the viewfinder or LCD screen and other times it is a bit dimmer?

[David Rakoczy]

It all depends on your stop... ironically while shooting at night in low light situations at a T.2 you can pretty much see what you see by eye, however, when shooting in daylight at the beach for example and wanting to hold a lot of DOF the T 8 or 11 will look very dark in the viewfinder... there are times while shooting time lapse I can not see at all.. nothing... except a faint circle which is the SUN in frame. In these cases we pull the Glass.. frame.. lock it off.. and replace the Glass (Filters).