Any Light Designer's?

I have been learning theatrical lighting design for the last year. I could hang, color, and focus. But now I can do basic design and board programming.

But my mind works in weird ways.

So here is my question:

If I have a pure black object on stage, how do I make it look blue? Color subtraction? Addition? And how do I do that? Or do I use a pure white object instead?

a reply to: theatreboy

I feel like making anything black appear to be anything other than black is much less efficient than making an object of any color appear to be blue. If the object being white is an option, that's the best option. Depends on a number of factors too. Anything else on the stage lit up? If not, super easy together you white object look black hahaha. Is the object going to be any other colors? If not, get yourself a blue object? I'm half kidding lol.
Seriously though, depends on your needs, so factor in any other environmental elements and your needs as it relates to the object itself. I don't think making a black object look blue is going to be discernable to your audience unless it's illuminated from inside maybe, and the object is rigid and somewhat translucent. Hope that helps!

a reply to: theatreboy

Lighting gel is subtractive color mixing.

Your question isn't as simple as it seems.
I have seen blue gel used that turned black clothing magenta.
Paints and dyes super-saturate colors to get blacks.
Most common are, red blacks, blue blacks, and green blacks.

If your object is glossy or has a high sheen, something as simple as hitting it with a blue gel will give it the appearance of blue.
I'm partial to GAM 815, moody blue.

a reply to: theatreboy

I went to long without editing my post.

I worked with Jim Moody, who helped create moody blue.
It's a great color for dance, in my opinion.
Yes I have been a professional Lighting designer for live performance since 1997. But only regional. I never looked to get a guild card, as I figured one of my bands would take off.

As per your object. . .
You can find the correct color to transfer your object. Whatever the color, with trial and error. Unfortunately, the mixing of additive (paint or dyes) and the subtractive (gels and/or leds) makes it difficult to give the definitive answer.

As per pure white. . .
It still shows in a blackout. I know the industry was all about white sets in the early 2000, but its not a great look.

Currently I work as a TD in educational Theater.

a reply to: theatreboy

What about a translucent dark blue object with a matte surface, and a light source inside it?

It would still look quite dark against the blacks, but would be blue on cue.

Also, there are probably metamaterials/iridescent coatings that would appear mostly black but would reflect the right wavelengths when lit. You'd probably have to 'notch filter' the key wavelength out of all other lights (perhaps with some sort of gel?). The narrower you get the band of the filter, the less noticeable it would be.

Also, perhaps if you used colour lasers or LED's for the source, the output spectrum would be specific enough to hide the fact that it wasn't carrying some particular frequency bands?

(PS, I'm not a lighting guy, more a physics guy).

originally posted by: chr0naut
a reply to: theatreboy

What about a translucent dark blue object with a matte surface, and a light source inside it?

It would still look quite dark against the blacks, but would be blue on cue.

Also, there are probably metamaterials/iridescent coatings that would appear mostly black but would reflect the right wavelengths when lit. You'd probably have to 'notch filter' the key wavelength out of all other lights (perhaps with some sort of gel?). The narrower you get the band of the filter, the less noticeable it would be.

Also, perhaps if you used colour lasers or LED's for the source, the output spectrum would be specific enough to hide the fact that it wasn't carrying some particular frequency bands?

(PS, I'm not a lighting guy, more a physics guy).

chr0naut, you did pretty good in theory.
Theater breaks too many real world rules, I'm not suggesting you are incorrect.
I think you are over complicating the solution. However you have given a solution.