Looking at the Samoiloff effect, an old stage lighting trick using the physics of reflected colour, On Stage Lighting brings together the old with some new technologies in the form of colour mixing LED fixtures.
In our article on Reflected Colour in Lighting we looked at how using saturated colours, particularly the primary light colours (Red, Green and Blue), can dramatically effect the way a coloured object looks to the eye. In a practical example, it meant that my blue LED keyring torch was pretty useless when it came to hunting for cables marked with either green or red PVC tape because the two marking became a dirty brown colour. It also told us something useful about lighting scenery and costumes with saturated light colours. If you haven’t already, check out the article.
Adrian V. Samoiloff – Lighting Magician
In the 1920s “electro technician” Adrian V. Samoiloff developed the use of this colour phenomenon to dramatically change a stage picture in the theatre, costume and sets using simple lighting changes. An article on one particular show in the New York Times describes a scene and then states:
“Then behind the scenes, somebody does something and everything is altered in a flash. The grim mountains become a Hindu temple, the frowning rocks melt into sands and palms and the tall, slender young woman becomes a stout Indian maiden.”
The “something” that somebody had done was to change the colour of the light on stage, having carefully used reflected colour theory to hide and reveal different elements in full view of the audience. A lighting magic trick.
Samoiloff apparently took the basic effect further by analysing the chemical make up of dyes and how they reflected different parts of the spectrum. Reports of these experiments suggest the use of minute differences between dyes that under white light look similar, but react to saturated colour in different ways. Samoiloff also stated that he used these effects along with “dazzle”, a camouflage technique. With regard to the science of dyes and their reflection properties, I am not sure how much of the dye analysis part of the story is puffed by the reports but either way, the basic magic trick still works!
Old Tricks, New Technology
With the advent of different forms of colour mixing fixtures, we have an even greater opportunity to use many different saturated colours on stage – and change them in an instant. Samoiloff made use the development of the “compartment batten” flood lighting system that became known as “Sammies”, a version of which can still be found as S63 battens in a few schools halls. Today we have Subtractive CMY and Additive RBG colour mixing in our moving lights and Red, Green and Blue in LED based fixtures such as cheap LED PARs.
As part of a colour theory lecture I take, we look at how different coloured light reflects on different fabrics of a costume. Using combinations of the light primary colours (Red, Green, Blue ) and secondary ones (Cyan, Magenta, Yellow), experimentation shows that sometimes a costume colour reflects well, sometimes not, depending on the spectral makeup of the light shining on it.
An extension of this is using three banners that are specially designed to demonstrate the principle behind the Samoiloff effect. The banners are each a pair of complimentary colours. The pairs are:
- Red / Cyan
- Green / Magenta
- Yellow / Blue
One colour in the banner reflects one part of the spectrum (eg. Red), the other complimentary reflects the other two light primaries (eg. Cyan = Blue and Green). This gives us the biggest opportunity for shift in reflected colour. Using an LED PAR shining at the first banner, outputting white (well, white for a cheap LED PAR) the colour appear to be Red and Cyan. Changing the LED to output only Red, the banner seems to be Red and Black but then changing the LED to Cyan, the pattern reverses to negative in Black and Cyan. Your eye almost assumes that the Cyan portion is, in fact, white fabric with a Cyan light on it. This large shift from +ve to -ve is startling and it doesn’t take long before you can see a whole host of magical reveals and possibilities using the Samoiloff effect.
Taking this demo further, using a colour mixing fixture (or simply gelled conventional fixtures in Red, Green and Blue) we blend light colours on all three banners and adjust, moving through parts of the spectrum where all colours look quite similar, before then snapping out to a dramatic change when they suddenly become different. The interesting thing about LED light sources is that they are quite “spiky” in different parts of their spectral output, throwing a whole extra dimension to this old theatrical effect. Subtle fades between levels of Red, Green and Blue creates major shifts in the reflected colour.
Create Your Own Samoiloff Effect
You will need:
- A piece of white paper
- Marker Pens – Primary Red and Primary Green
- Gel Filter Swatchbook
- A dark place to be
Physics teachers use this technique to demonstrate how reflected light works. Take your paper and write “Red” using the red marker pen. Underneath it using the green pen, write “Green”. Finding some primary red and green gels in your swatch book (Lee 106 or Lee 026 and Lee 139 are good), turn all other lights off and fire your torch at the paper. Using no gel, you see both words written on the paper.
Adding a red gel to the torch, the word “Red” gets fainter and, if you are lucky, disappears. Moving onto the green gel, the opposite happens, hiding your word “Green” while making the “Red” writing appear black. Once again, reflected colour theory doesn’t fail us and the magic trick is proven to still be good in 2011…
If you want to move further onto more complex effects, you can try not only the primary filters; L106, L139 and L132 (or L079 or L119); but also some versions of the secondaries in the form of:
- Lee 116 Medium Blue-Green
- Lee 126 Mauve
- Lee 101 Yellow
These are just one take on the secondary colours, there are other gels which fall within the secondary ranges, there are others that you might like to look at such as L172 Lagoon Blue, L128 Bright Pink and Lee 104 Deep Amber. They all produce slightly differing results.
The Magic of Light
But all this is a pretty crude demonstration and highlights the extremes of the Samoiloff effect. Using complex coloured fabrics and patterns on stage, it’s not hard to see what a massive influence we as lighting designers have on how colours are seen, or not, by an audience.
We can create magic on stage using light and colour. We can also really mess things up.
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Rob is a Lighting Designer and Moving Light Programmer and currently Senior Lecturer in Technical Theatre Production at Bath Spa University in the UK. He is also the Editor of On Stage Lighting and runs workshops in stage lighting practice.
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