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Rainbow in UV and IR

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#1 A.S.

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Posted 24 September 2017 - 21:07

Several months ago I have looked for rainbow images, however I wasn't able to find any IR or UV
rainbow image with colors. There are only black and with images.

Until now I have taken two times some IR and UV images of a rainbow. Here are some photos of my second try. These photos are not perfect, there are some vignetting effects with the lens notably for the right upper edge and there are some dichroic effects visible especially due to the reason that I have used a high color saturation, however I want to make different colors visible. It seems that it could be interesting to take rainbow photos with different UV filters. Unfortunately the rainbow was slowly disappearing during my photos with the filter stack ZWB1 and BG39, however it is possible to see that there are two colors visible with some space between both bows which indicates that one bow is from ultraviolet light and one from infrared. Even with the Baader U filter it seems there is a second weak bow visible.


All images were taken with 20mm f/4 lens from igoriginal and a full spectrum modified Olympus Pen E-P2.

Ultraviolet Light: Baader U 2" without color channel swap.
Attached Image: P9142650-UV-Baader-pupil20mm-without-channel-swap_kl.jpg


Ultraviolet Light: Baader U 2" with color channel swap to obtain blue sky.
Attached Image: P9142650-UV-Baader-pupil20mm-with-channel-swap_kl.jpg

Visible Light: Hoya UV/IR Cut filter.
Attached Image: P9142652-VIS-Hoya-UV-IR-Cut-pupil20mm-kl.jpg


Infrared Light: Zomei IR720 filter without color channel swap.
Attached Image: P9142654-IR720_pupil20mm-without-channel-swap_kl.jpg


Infrared Light: Zomei IR720 filter with color channel swap of red and blue channel and some change in the green channel to obtain a slightly blue sky and slightly yellow leaves.
Attached Image: P9142654-IR720_pupil20mm-with-channel-swap_kl.jpg


Ultraviolet Light: 1.8mm ZWB1 and BG39 without color channel swap.
Attached Image: P9142655_UV-ZWB1-BG39_pupil20mm_without-channel-swap_kl.jpg

Edited by A.S., 24 September 2017 - 21:11.


#2 Mark

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Posted 24 September 2017 - 23:38

What a great idea!

It would be interesting to see an overlay of these images to see how much the range of the rainbow is extended with the UV and IR images added.

#3 OlDoinyo

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Posted 25 September 2017 - 03:21

By glancing at the horizon, one can tell that the UV rainbow is inside the visible, whereas the IR rainbow is outside. This is of course what one would expect. The Alexander's Band effect is visible at all wavelengths. Only the IR image seems to resolve any supernumerary arcs, but one would expect those to be similar to visible.

This is an interesting way to test for an IR leak, and more sensitive than I would have supposed. A slit and diffraction grating would probably work even better, though.

Edited by OlDoinyo, 25 September 2017 - 03:26.


#4 JMC

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Posted 25 September 2017 - 05:31

Really cool. Saw a nice strong rainbow about a week ago and wondered what it would look like in UV and IR, but was driving at the time and didn't have my multispectral camera with me. Given this, I'll shall travel more with my camera in the car in future.

#5 Andrea B.

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Posted 01 October 2017 - 18:28

Very cool!

I've tried a couple of times to capture an IR rainbow, but did not get good results.
For one thing, ya gotta be ready to shoot quick in IR or UV when a rainbow appears. :D
Andrea G. Blum
Often found hanging out with flowers & bees.