Iridescent wing scales

Charles Krebs · Post by **Charles Krebs** » Thu Jul 21, 2005 10:18 am

As with some others, my last two posts have vanished... so I'll give them another try.

I've tried photographing iridescent butterfly wing scales a few times with poor results. I came across a specimen that had several iridescent spots on the wing so I decided to give it another try. The first few efforts were pretty sad looking. So I decided to try a lighting method that has worked well for me with iridescent beetles. I cut a ping-pong ball in half and then cut a hole at the top of the hemisphere large enough for the microscope objective to fit through. I placed the hemisphere over the iridescent section and illuminated it with two fiber optic light guides. Worked out pretty good.

On this specimen, the iridescent scales have a very different shape from the other scales on the wing. They have a curved shape, and the tips are smooth an rounded. The "normal" scales are flat, and have three lobes at the tip.

Again... I am constantly amazed every time I examine this subject.

Top image: 7X objective, 2.5X photo-eyepiece, Canon 10D
Lower image: 10X objective, 2.5X photo-eyepiece, Canon 10D

Ken Ramos · Post by **Ken Ramos** » Thu Jul 21, 2005 3:28 pm

Pretty neat trick with the ping pong ball Charlie, I have never seen scales like these. Beautiful

Erland · Post by **Erland** » Mon Aug 08, 2005 4:11 pm

These two pictures of the scales and your "Butterfly Wing scales" post, is amazing. As I understand it (from dragonfly reading) the iridescent colours are caused by difraction of different wavelenghts in the surface of the scales. Wonder if the curved shape in any way contribute to that ?

The lightning is so smooth and the details stunning.

Erland

Charles Krebs · Post by **Charles Krebs** » Mon Aug 08, 2005 8:54 pm

Erland... thanks for the kind comments. A very interesting article about this phenomenon can be found at:
http://newton.ex.ac.uk/research/emag/bu ... c-text.htm

Erland · Post by **Erland** » Tue Aug 09, 2005 1:32 pm

Charles Krebs wrote:Erland... thanks for the kind comments. A very interesting article about this phenomenon can be found at:
http://newton.ex.ac.uk/research/emag/bu ... c-text.htm

Great reading, thanks for that. Well I think I said interference instead of difraction, at least that's what I meant

Erland