Coloured hives

[Repwoc]

There are two things to consider, the quality of the light source and the surface that is reflecting the light back. The colour wheel below shows the three primary colours, the three secondary colours and 'white' in the centre. It is difficult to get true white as almost all sources are bias to one or the other colours. If you place a piece of pure red cloth in the centre or in the red or ether of the secondarys it will look red, as there is red light falling on it and is reflected back. If you move it to the blue light it will appear to go black, no red light to reflect back.

That is all true. However, with your theatre lighting you are dealing with additive colour mixing using coloured lights. With painted beehives, coloured fabric or whatever we have subtractive colour mixing. Normally the light source is daylight, a much broader spectrum than is provided by 3 coloured lights, and includes the visible specra of humans and bees.

With additive colour mixing, the primaries are red (R), blue (B) and green (G) and secondaries are cyan (C), magenta (M) and yellow (Y), as you said. The primaries correspond to the colour sensitive cones in human eyes, which contain pigments. With subtractive mixing this is reversed, so C, M and Y are the primaries and R, G and B are the secondaries. Ie to make R, mix M and Y paint.

The colour wheel does serve to illustrate the point I made about absorbtion and complementary colours. In the centre there is white light where the R, G and B lights intersect (R + G + B = W). Just below the white area, where the B and G lights intersect but not R, the colour is C. Ie, C = W - R. So if a painted surface is illuminated with daylight (ie white light) and it absorbs R light it is perceived by humans as C. If it absorbs only a little red light it will be pale C, if a lot of R is absorbed the C will be deeper. For the surface to appear white, it must reflect all the incident light - and obviously for black it must reflect none.

If you replace the red with ultra violet in the wheel you will get the colours a bee might see with and putting something red anywhere in the wheel will look black as there is not a red 'source' to reflect back.

The reason your red cloth looks black is because you are illuminating it only with light that it absorbs. That doesn't mean it absorbs all light except R - in fact it is reflecting M and Y in the human visible spectrum and (probably) UV in the bees' visible spectrum. So since it reflects some of the light in the bees' visible spectrum, it will appear coloured to them - but not black.

 

[BKF Admin]

This is what I was looking for

 

[Hombre]

That being the case Admin, two bee keepers a short distance from an angry colony of bees flying.

One bee keeper is wearing a black bee suit and we accept that he will probably be quickly covered in bees.

How about the bee keeper that is wearing the red bee suit? If the bees see red as black, should that bee keeper also not be quickly covered in bees.

Perhaps we whould re-run the swarm story of the other day with the rabbit dyed red and see if Joey felt as lucky? (just joking about joking)


My thinking was with you Admin, but I am now questioning myself - the snag is, I'm not getting any sense [[from myself, so nothing new there then]].

I do realise that they will probably get taken up by the fashion police well before they get mobbed by the bees.

 

[Somerford]

Am I correct in thinking that 'Von Frisch', the (Swiss?) scientist did some experimentation on this subject around the time he did his work on the dancing bees - and he found out what colours bees responded to and shapes too ?

It might be worth a look if there is a link anywhere on the interweb that will save alot of time and wringing of hands generally.

For the record I respond favourably to a nice pinky/tan colour commonly found on the female of the **** sapien species, closely followed by a golden colour commonly found as a result of mixing barley and water in the Glens of Scotland.

oh, and the colour of money is not bad either.

regards

S

 

[Repwoc]

Which bee did you ask?

Do you know where the table came from Admin?

Obviously from the previous discussions I disagree with at least some of the table, with regards to subtractive colours. Clearly, if you shine a light source that contains just red light into a bees face then the bee won't be able to see it (maybe that's what is meant in the table). However a red pigment absorbs principally cyan and therefore reflects UV which the bees can see - so it won't look black to a bee.

If you think about it there are lots of red and pink flowers. These would all look pretty unattractive if they were black. Except for black tulips (and they aren't black or natural) there aren't any black flowers I am aware of so it's not something that nature selects for.

 

[Hombre]

A very Interesting thread. I suspect that we will all be the wiser for it and are probably deep in personal research even as I speak.

Karl Von Frisch was an Austrian, born in Vienna.

 

[Hivemaker.]

Extract.
To a honey bee, however, the color red is invisible. They see red objects as black, or the absence of color.

http://gears.tucson.ars.ag.gov/ic/vision/bee-vision.html

 

[RoofTops]

Jurgen Tauz's book on bees has some interesting information. For example, when flying quickly bees turn off their colour vision and see the world in black and white. The biological explanantion for this is the small bee brain can't do too much at once so if it is busy navigating, which it does mostly by landmarks, it does not need colour. It is only when the bees gets close to a flower and slows down does the colour vision switch in.

On returning to the hive the bees are much less interested in colours and hives painted in plain colours are not readily distinguishable by colour alone, although they see blue most strongly.

He says patterns made of horizontal stripes are recognised by the bees rather than simple geometric shapes. Curiously, the complex pictures painted on the front of bee hives in some European countries are effective. The bees don't see it is a picture but as a unique pattern.

 

[BKF Admin]

Thanks for that Rooftops