Shooting into a mirror

[Andrew Jackson]

This is a pretty quick question that probably doesn't deserve it's own thread, but I searched and couldn't find anything related to it. Anyways, I'm going to be shining a light into a mirror and filming it. How would you take a reading of this? I'm guessing with a reflective meter, but I'm not really sure. Any help would be much appreciated!

[Mikael Gustafsson]

Hi.

 

I'd try metering the scene the mirror reflects toward the camera, not the actual mirror in itself. Ought to be quite simple with a spot meter to meter even through the mirror though. An incident one should work as well, by pointing the dome in the direction of the main reflections.

 

I'm not aware if mirrors actually change the incoming light at some minor degree, from what I've heard they reflect basically everything without much light loss(working well as reflectors etc).

 

Hope this helps, even at some degree.

 

Mikael.

 

 

This is a pretty quick question that probably doesn't deserve it's own thread, but I searched and couldn't find anything related to it. Anyways, I'm going to be shining a light into a mirror and filming it. How would you take a reading of this? I'm guessing with a reflective meter, but I'm not really sure. Any help would be much appreciated!

[Drew Hoffman]

Mirrors reflect almost all of the light that hits them. There's a negligible amount of light loss, but not enough to worry about compensating. I agree with metering the scene itself, just get an incident reading and you should be fine. If you're in doubt, try bracketing the exposure. I wouldn't think of taking a spot reading off of the mirror unless you're basing your exposure off the face of the light.

[Kevin Zanit]

Just meter and shoot it as you would if the camera was facing the action directly.

 

When really in doubt, hold a gray card in the area you want exposed properly. Make sure it doesn?t move, take a meter reading directly on the object, and then from the reflection. Compute the light loss between the two readings, then meter the scene like you normally would and add the stop compensation into it.

 

For example, if I am loosing 1 stop from the reflection, and I then take an incident reading at my subject that comes up at a F8, then I know if I want the reflected image exposed correctly, I need to shoot at a F5.6.

 

As was said though, a good clean mirror will have very minimal light loss.

 

Kevin Zanit

[Michael Collier]

The only thing I would add to that advice is if the mirror is heavily soild, like an old 50's mirror styled to be dusty and decayed, I would spot meter through the mirror. It should be obvious to the eyes if the mirror is loosing a lot of light, so you can make a decision based on that. You can either incident it if you want to judge the reletive exposure of a surface (the wall behind, etc) or you can spot the light itself if you want to determine if the light itself will blow out or not.