shooting in a mirror

I don't know the physical layout of your shot, but I've done many mirror shots and found it pretty easy to keep the camera out of the shot. Your typical composition is an over-the-shoulder shot of the subject looking at him/herself, with the camera reflection just out of frame. If this is what you want, I can think of 3 methods of achieving your shot, offhand:

1. If the actor's FX makeup is primarily facial, s/he can sit in front of the mirror and you can achieve the shot in-camera. Since we're only seeing the back of the actor's head and shoulder, viewers will likely not think about it since their attention will be on the face in the mirror. If you use a long lens to narrow the focal length, the back view of the actor will be thrown out of focus, further directing the viewer's attention to the reflected image. You can then intercut the scene with a shot looking straight into the face of the actor, sans makeup but reacting to what s/he, and we, see in the mirror angle.

2. If the above won't work for what you need, there are a couple ways I can think of to do the shot as an effect. In the simpler version, lock down the camera and have the actor perform the entire scene in the mirror. Then change the actor's makeup and have him/her redo the scene. This should be carefully rehearsed so that the performance is as identical as possible. The camera must not move, either between the shots or during the take. Then, in post, generate a split screen image with the non-made-up actor on one side and the FX version on the other. Soften the border slightly to mask the split.

This technique will only work if there is a clean separation between the actual and reflected image of the actor. If the composition will be such that the actor's body or movement will overlap with the reflected image, then I recommend...

3...using a chroma key. Again, lock down the camera and have the actor perform the scene in front of a green screen background. Change the actor's makeup and shoot the scene a second time, this time shooting the actor as though we are looking at his/her reflection -- but we're not. S/he duplicates the action of the scene in makeup. In post, flip the image and key it in over the green background, lining up the timing of the action as best you can.

When using this technique, be sure to carefully figure what the proper eye line for the actor's "reflection" should be, then shoot it the OPPOSITE way so that when you flip the image in post it will be correct.

Hope this makes sense and helps you.

That makes sense, and thanks. I'm a pretty technical editor. I write and sell my own chroma-key plug-in (VKey2), and I do lots of CG stuff. I did a commercial shot in an office building where we had the subject looking into a mirror and I had a hard time getting the angle and lighting I wanted without getting equipment in the mirror. Just for the sake of avoiding weirdness, I am leaning towards a green mirror so I can composite a 2nd shot into the mirror.

The fact that the reflection will look noticeably different gives me some latitude, I think. Since I've never done this, and the shots in the mirror will be integral to the story, I'm wondering what I'm forgetting.

1) shoot from the back of the actress with green panel in place of mirror
2) shoot front view of "normal" actress
3) shoot front view of "evil" actress and reverse for comp into shot 1
(there will also be some side/profile shots for continuity)

Am I forgetting anything important? How does the 180 degree rule work here? Can I switch from back to front views with no transition? I guess I'll be Ok, because it will actually be about 150 degrees of angle change.

Thanks for the insights. I'll add them to my notes. We should be shooting this fall, so I have some time to think this through and storyboard the actual shots.

Doug

p.s. If I can, I'm going to setup a bathroom set in my 16x24 studio with 12 foot ceiling, so I can get the lighting and camera angles perfect. These shots, and the lighting for them, are too important to the movie, to shoot in a cramped bathroom.

Sounds like you've pretty much got it figured.

oakstreetphotovideo said:

How does the 180 degree rule work here? Can I switch from back to front views with no transition? I guess I'll be Ok, because it will actually be about 150 degrees of angle change.

Click to expand...

You should be fine intercutting the two. It's just like an over-the-shoulder shot with 2 people, so as long as the eye lines are in opposite screen directions there shouldn't be any confusion -- especially because, presumably, in one angle the actor will be in makeup and in the other she won't, which should minimize any feeling of a jump cut.

The angle of reflection = the angle of attack with reflective surfaces. Draw a line perpendicular to the face of the reflective surface (assuming a flat mirror here). Plot a line from all of the objects in the room to the mirror, opposite that is where you'll not want to place the camera Physics...it's all physics. I found all this stuff searching for lighting stuff and getting googled toward University Physics articles. Angle of Reflectance is the specific term for this.

That's useful information for someone who actually wanted to use the reflection. The trouble comes in when you want the person standing directly in front of the mirror and their reflection also, because to get the primary image of the person and the reflected image when the person is standing square in front of the mirror, the camera has to be roughly on the same axis as the incidence and the reflection. If the camera is close behind the subject, the camera will always be dangerously close to being in the reflection, if not in it. The ratio of the subject-mirror distance to the camera-mirror distance, combined with the lens's field of view, which would provide for a minimum distance the camera can be from the mirror before it enters it's own, reflected field of view. The size of the mirror is also an issue here. If you move the camera far enough back and zoom way in, then the camera can be off axis by only a few degrees and still be far enough to the side to avoid being seen (because of the actual distance to one side and the lens's narrower field of view). Since the subject is much closer to the mirror, the subject can be slightly off axis the other direction and still appear in the mirror and in the shot.

Otherwise, you have to set it up like a bank shot, with the subject way off to one side of the mirror, which may not be desirable.

None of these things really matter to me, since I'm replacing the image in the mirror with a different image, no matter what. What I was asking was simply, "what am I missing that's going to create a problem when I get to post?". Experience is a great teacher. In this case, I'd like to learn from someone else's mistakes. I know this sort of thing gets done all the time (like in Terminator 2).

Given that you're going to end up compositing the shot anyway (what with a different reflection than subject)...

My thought would be to shoot over the shoulder of your subject, or however you want to frame it, and make sure you DO see your camera/etc in the mirror, then for your reflection image, shoot from the "mirror's POV" into the reflected room (whether it's the same room or not). It might be beneficial to mask off the mirror surface with some greenscreen, simply to make matting easier, though if it were a static shot, this might not be an issue.

The reflection in the mirror continues the line of sight into the reflected image... You need to know the distance between the camera and the mirror, the distance between the mirror and the subject, and if you're seeing a wall or floor in the reflection, that distance too.

Suppose for your primary shot you shoot from a high angle down toward the mirror, somewhere in the reflection you will likely see the floor or a wall, you'd want to measure the distance from the camera to the mirror and add to that the distance from the mirror to that point of contact with the floor or wall. Then when you shoot your reflection, you shoot from the same height, at the same angle as the initial shot, and ensure your wall or floor distance is the same. From the various measurements you should be able to work out where in that faked reflected image your subject would appear.

The important measurements are camera height, angle and focal length, distance to the subject in the reflected image, and distance to the floor/wall/etc in the reflected image.

I hope that made sense.. I'm having a bit of an off day with explaining things.

Perhaps you can make a matrix flow-mo style green screen blink that the camera stands behind with just a hole for the lens.

That's good stuff, Will. Thanks.