Madagascan Sunset – I NEED A FAVOUR / HELP!
This is one of my favourite microscopy images: the small section of a Madagascan Sunset Moth wing, an image created by combining 997 separate frames in the biggest focus stack I have ever completed, shot using a Mitutoyo Plan APO 20x objective. The image is currently in the running for the Visualizing Science People’s Choice contest. It’s in second place.
I would kindly ask for you to vote for this image. Voting can be done here: blog.cdnsciencepub.com/visualizingscience/
Anyone can vote, from anywhere in the world. The website is a little difficult to use on mobile platforms so you might need to use a laptop/desktop – if everyone reading this message were to give me two minutes of your time, this image would take first place easily. If I’m asking you for two minutes, I’ll give you two minutes of my own time with a fun description of what we’re seeing here:
The wings of some butterflies create colour by unconventional means. Colour is usually an absorption / reflection thing; something absorbs all light except for the wavelengths of light we associate with orange, we see that object as orange. Another way to create colour is through optical interference, wherein structures cause light waves to interact with each-other, sometimes cancelling out certain frequencies or amplifying others. We see this all the time around us, in everything from soap bubbles to oil spots; I’ve seen it in ink, coffee and even snowflakes as well. Some insects have evolved to create the same sorts of colours – including this moth.
Because the colours are partially based on the trajectory of the incoming light in relation to the surface of the scales on the wing, if the angle changes than the colour might change as well. This is why we see colour shifts along the curve of these scales, and why I opted to photograph this wing at a rather extreme angle instead of “flat” to the focal plane of the camera. A lot more work in post-processing, but it reveals some extra magic in the process.