• Ultraviolet Photography

Tomatillo trio

2 replies to this topic

#1 Mark


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Posted 07 February 2018 - 23:23

I finally remembered to grab more than just ONE of my test-subjects-to-be during my last visit to the supermarket (so I can capture multiple views per shot). Shown below across a multispectral set of 5, this tomatillo gave me a nice show under my lights/lens/filters/etc. And it also presented a little surprise of its own.

Lets start with a VIS view of the subject, for reference:
Attached Image: 2018-02-03_19-02-43.jpg
(Front left: unpeeled/husk intact, Front right: bisected, Rear middle: husk removed)

Looking at the UV image, save for some of the fruit's flesh it turns mostly UV dark inside and out - especially those seeds!
Attached Image: 2018-02-03_18-59-12.jpg

Technically speaking, I summarize my findings on this UVIVF image as: So cool! There. I said it. And I stand by my findings 99.846%.
Attached Image: 2018-02-03_19-05-54.jpg

This IR showing isn't as drab as I'm accustomed to, given the nice subtle blue hue in the husk - though not enough to impress me much.
Attached Image: 2018-02-03_19-09-01.jpg

Now, not only do I like the results of this UVIIF image, but there's a curious thing going on here. Notice the base of the cut stem on the fruit in the background. In this image it is dark. I'm a little surprised by this, because by comparison that same area is bright (or at least bright'ish [again, another technical term ;)]) in all of the other images.
Attached Image: 2018-02-03_19-13-14.jpg

Hardware (all images): Lens: 50 mm Nikon Series E + 12 mm extension, Body: Nikon D750 N1404 [broadband]

Edited by Mark, 07 February 2018 - 23:25.

#2 Andrea B.

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Posted 01 March 2018 - 17:31

Isn't is just odd/cool that the huskless green tomatillo looks like its red tomato cousins when photographed under black light?

This is a beautiful study.

When I lived out in California I saw lots of tomatillos grown in home gardens, but I never learned how you could tell when they are ripe. :) It is probably that the husk gets papery? I'm going to go look that up.

ADDED: For those eagerly awaiting the answer: Select tomatillos that are still bright green, but with husks that have turned tan and papery. Once the fruit turns yellow, it's overripe and has lost its flavor.
Andrea G. Blum
Often found hanging out with flowers & bees.

#3 Andy Perrin


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Posted 02 March 2018 - 02:00

It is quite fascinating. If you convert the UV to the Lab color space and tighten up the a and b channels, you can see some color inside, which makes me wonder if it would be a bit more (naturally) colorful under a broadband source:

(convert to 16 bit, convert to Lab, tighten a and b channel histograms, convert back to RGB and save as JPG)
Attached Image: mark lab.jpg

Edited by Andy Perrin, 02 March 2018 - 02:01.