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Not all plastic or glass that's opaque to visible light is opaque to UV.

Yeah, flowers have interesting UV patterns.

At least the Wood anemones do http://www.naturfotograf.com/UV_ANEM_RAN.html

So our hero could go to a botanical garden or contact a botanist to see if there is some unexpected patterns to find and perhaps which flowers to look at.

I suppose that many flowers will look different, as well as the plumage of many birds, which have UV color patterns that humans usually do not see:

http://www.usatoday.com/news/healthscience/science/aaas/2002-01-03-budgies-glow.htm
http://commons.wikimedia.org/wiki/File:Cockatiel_under_blacklight.jpg
http://www.naturfotograf.com/UV_ARNI_ANG.html
http://www.naturfotograf.com/UV_LATH_PRA.html
http://i.livescience.com/images/i/7881/i02/fish-uv-pattern-100225-02.jpg?1296089823

There are a number of species of animal that can see ultraviolet light, and a number of plant and animal species have evolved to take advantage of this. Parrots are known for having UV patterns in their feathers, butterflies use UV patterns to communicate with each other, and most flowers have UV patterns to attract insects. Some fish-eating birds use UV light to help identify fish underwater.

So if you are truly able to see UV light, you should be seeing a very interesting world!

I suppose that many flowers will look different, as well as the plumage of many birds, which have UV color patterns that humans usually do not see:

http://www.usatoday.com/news/healthscience/science/aaas/2002-01-03-budgies-glow.htm
http://commons.wikimedia.org/wiki/File:Cockatiel_under_blacklight.jpg
http://www.naturfotograf.com/UV_ARNI_ANG.html
http://www.naturfotograf.com/UV_LATH_PRA.html
http://i.livescience.com/images/i/7881/i02/fish-uv-pattern-100225-02.jpg?1296089823

There are a number of species of animal that can see ultraviolet light, and a number of plant and animal species have evolved to take advantage of this. Parrots are known for having UV patterns in their feathers, butterflies use UV patterns to communicate with each other, and most flowers have UV patterns to attract insects. Some fish-eating birds use UV light to help identify fish underwater.

So if you are truly able to see UV light, you should be seeing a very interesting world!

Flowers are often more varied in the UV than in the standard visible light range.

The APS-H sensor is 28.7 x 19 mm. To resolve 13,280 pixels along the length of the sensor, you'd need a lens that could resolve 463 lines per mm (232 lp/mm). According to the laws of diffraction, this is impossible for f-stops greater than approximately f/3.24. (1500/463 = 3.24). That doesn't give you a lot of depth of field to work with, if you want to resolve all of those pixels. And you don't have a bellows design capable of tilts and shifts, as do 4x5 large-format cameras, so that compounds the problem.

The practical problem right now is that there just aren't any lenses that resolve 232 lp/mm for normal photographic use. There are some very specialized lenses that deliver many hundreds of lp/mm. e.g., the 28 mm f/1.8 Ultra-Micro-Nikkor resolves about 600 line-pairs per mm or 1200 lines/mm: http://www.naturfotograf.com/lens_spec.html/. The conditions under which the lens resolves that many lp/mm are very limited, however (macro only, at a very specific magnification).

Can someone please explain the technical reasons why so many space photos are "false color" based on X-Ray or infrared spectrum, even from modern spacecraft? Is there no color spectrum in outer space?

Of for a great visual comparison, see this flower in both visual spectrum (ho hum) and false color UV (bull's-eye!).

Even more impressive is all the details in this otherwise monochromatic flower that insects see.

The answer? To get information that our limited eyes can't perceive, into a range we can perceive, and therefore, learn from.

"In visible-light, a single photon can produce a single electron of charge in a pixel, and an image is built up by accumulating many such charges from many photons during the exposure time. When an X-ray photon hits a CCD, it produces enough charge (hundreds to thousands of electrons, proportional to its energy) that the individual X-rays have their energies measured on read-out." (per X-ray astronomy on Wikipedia) So it's also seems easier to capture these high energy wavelengths.

Sadly we can't make subtle IR observations from Earth, as the water vapor in our atmosphere absorbs a significant amount of that radiation. (per Infrared astronomy)

Can someone please explain the technical reasons why so many space photos are "false color" based on X-Ray or infrared spectrum, even from modern spacecraft? Is there no color spectrum in outer space?

Of for a great visual comparison, see this flower in both visual spectrum (ho hum) and false color UV (bull's-eye!).

Even more impressive is all the details in this otherwise monochromatic flower that insects see.

The answer? To get information that our limited eyes can't perceive, into a range we can perceive, and therefore, learn from.

"In visible-light, a single photon can produce a single electron of charge in a pixel, and an image is built up by accumulating many such charges from many photons during the exposure time. When an X-ray photon hits a CCD, it produces enough charge (hundreds to thousands of electrons, proportional to its energy) that the individual X-rays have their energies measured on read-out." (per X-ray astronomy on Wikipedia) So it's also seems easier to capture these high energy wavelengths.

Sadly we can't make subtle IR observations from Earth, as the water vapor in our atmosphere absorbs a significant amount of that radiation. (per Infrared astronomy)

'Cause I love non-visible light photography - but quartz lenses are a fortune - if you can find one.

Its been known for over a decade that flowers have a surprising degree of UV variability, to which pollinators [but not humans] are sensative.
e.g.:
http://www.naturfotograf.com/UV_flowers_list.html
http://www.bbg.org/gar2/topics/wildlife/2000su_bum blebees.html