Convex Mirrors Part II: Reflections

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An effect like this, that mimics reflected light from outside, is impossible in a small space without a convex mirror – but it has to be the right mirror and the right light. We need a mirror with just enough curvature to reduce the size of the light source and give us the depth of field of a short focal length lens – but not more than that. If the curvature is too great, like in industrial safety mirrors, an enormous amount of light is lost.

So far, the most effective mirrors I’ve found are panoramic rear view mirror replacements.They do a lot of work with no effort. First, there’s no epic struggle with spill, which is what would happen if you attempted directed projection. You only get what bounces off the mirror and that can be easily and quickly reshaped if needed. Second, the curvature is perfect – deep focus and acceptable (although considerable) light loss.

In this setup I used a tungsten 2K which had just barely enough power as long as I didn’t gel it to daylight. I closed the blinds instead. Since most of the light is not hitting the mirror and what is hitting the mirror is shrunk, it takes some horsepower to make this technique work. If I were to throw a full CTB on the 2K it wouldn’t have the punch. An HMI (like a Joker 800) is probably a good bet although I haven’t had a chance to test that yet, or possibly a new LED fresnel.

Even with the ability of a convex lens to project a deep field of focus, this setup has a relatively large footprint – about 6 feet of depth. It looked like this:

The movement comes from a small fan directed at the curtain. This was just for convenience, it could almost as easily be moved by hand or by a larger fan at some distance. The rear view mirror was used like this:

In the photograph above – and in the diagram – you can also see a small spot mirror. It’s just a 1″ round plane mirror that gives us the light on the books on the left of the frame. You really don’t have to give any thought to motivating light in something like this – almost anything is plausible. The pine tree is a small artificial Christmas decoration I found in a thrift store for $2. The object itself is maybe 8 or 9 inches tall but you can see the shadow – perfectly sized – in the left center of the frame. I am always on the lookout for small elements like that.

Given the size of these images it’s a little hard to see everything that a convex mirror gives you. Neither direct projection nor a plane mirror would give you the combination of the texture of the curtain visible in the image below and the size of the coverage.  It adds a granularity to the light which I really like. If the curtain is not moving, those qualities are still there but a little less prominently – we see patterns when they move.


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