Two individual butterfly wing scales

Charles Krebs · Post by **Charles Krebs** » Thu May 26, 2005 5:40 pm

Well I'm back. Spent a couple weeks in southern Louisiana eating crawfish, listening to zydeco, and photographing birds. My microscope table needs a good spring cleaning and organizing, but I had to take a few pictures first, so I looked at some butterfly wings.

Here are two individual scales photographed with a 40X using brightfield illumination.

piotr · Post by **piotr** » Thu May 26, 2005 6:18 pm

Hi Charlie, good to see you back

Fascinating subject, indeed! Are the butterfly wing scales a birefringent subject?

micron · Post by **micron** » Thu May 26, 2005 7:22 pm

Very nice images Charlie - how do you get the background so white?

All the best,
Ron

Charles Krebs · Post by **Charles Krebs** » Thu May 26, 2005 8:12 pm

Ron... I set the "white" eyedropper in "levels" in Photoshop to (RGB) 245/245/245 and click on the white area of a brightfield photo. This eliminates any color casts and brings the whites up to just below complete "washout" (which would be 255/255/255).

Piotr... I'm not sure if some of these scales are "birefringent". Certainly there are some scales that have intense colors if light hits them at certain angles, but look very "plain" or dark when illuminated from another angle. (Just like some hummingbird feathers). I've always thought of this as iridescence.

lacerta · Post by **lacerta** » Thu May 26, 2005 9:58 pm

Welcome back Charlie ! Great image.
George

piotr · Post by **piotr** » Fri May 27, 2005 7:22 am

Charlie, thank you for the explanation. I wondered if any of the insect scales are a good subject for observation in polarized light.

GreenLarry · Post by **GreenLarry** » Fri May 27, 2005 10:28 am

Charles Krebs wrote:Ron... I set the "white" eyedropper in "levels" in Photoshop to (RGB) 245/245/245 and click on the white area of a brightfield photo. This eliminates any color casts and brings the whites up to just below complete "washout" (which would be 255/255/255).

How do you enter the figures? I went into levels, set to RGB, and tried to enter the 3 sets of 245, but the second figure has to be a number bewteen 0.10 and 9.9.
Which eyedropper do you click on, there are 3.

Charles Krebs · Post by **Charles Krebs** » Fri May 27, 2005 11:45 am

Larry,

If you go to "levels" in Photoshop, in addition to the sliders you will see three eyedroppers in the lower right. If you double click on them a dialog box opens up and allows you to set the RGB value you want for that eyedropper. By default the "white" eyedropper is set for 255/255/255. It can be very useful to put in values that suit particular subjects. Here I used 245/245/245, but the subjects are quite dark so it worked out OK. These values might be too high if you have subjects that do not have as much contrast with the background.

GreenLarry · Post by **GreenLarry** » Fri May 27, 2005 12:12 pm

Thanks for that, i got it now!