Tuesday, May 31, 2011

Reflected UV shots in the park today - decoding UV colors

Just preparing and testing for a field trip, so some output here for your - hopefully - viewing pleasure...

UV camera, Baader-U filter, my ReflectionDisc for in-camera whitebalancind, leading to the following UV "color" palette:



[click on image to see a larger one]

The 375-390nm group (violet UV reflection):








The 350-370nm group (yellow UV reflection):








That last shot, a Helianthus tuberosus (in female state) image is quite interesting, as the full blooming flower shows a 350-370nm reflection, whereas the younger buds show some in the 375-390nm range. Obviously there are development stages in UV reflections, I would assume .

[excuse the little motion blur in some images, it was quite windy today...]

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Wednesday, May 25, 2011

UVIR camera relative channel sensitivity for UV

(currently being reworked)

Full spectrum camera spectral response; simple test

To figure out the approximate spectral response of my full spectrum converted camera, I played around a bit with some gratings and my stabilized, continuous Xenon light source. I also found a linear spectra of my Xenon lamp, so with its help an approximate calibration of the recorded spectra is possible.

The first line is the Xenon spectra, the second the unfiltered spectra as recorded by the UV sensitive camera, the third line filtered through a Didymium calibration filter.

[click on image to see a larger one]




So from that and the color tests I published before, I would estimate that this full spectrum camera has a 320nm - 1000nm UV-VIS-NIR response. Actually I think it is more, as in such an image the exposure range limits the recording of fainter responses at the ends of the spectrum.

Found some better software which allows to read out such optical spectra. Here the results of using such:


On top the spectra as taken by photo, underneath the read out and calibrated spectra using known data high pressure Xenon spectra. The x-axis is in Angstroms, so knowing that 10A equals 1nm, it is easy to understand.

Again, please remember that the grating used was not really made for UV, but for VIS + NIR, so no wonder the spectra ends around 380nm. The real sensitivity to UV of that converted camera is quite higher, but I haven't found its limits yet.


Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

A few quartz flourite UV lenses on the bench

As I was taking some measurements with the Coastal Optics UV-VIS-NIR Apo 60mm, I thought why not also testing a few other fully color-corrected lenses while I'm at it... (forgot the Coastal Optics 105mm, unfortunately...)

[click on image to see a larger one]


[validity: approx 310 - 750nm]
Interesting to note, how similar the older designs (Zeiss UV-Sonnar 105mm and LOMO UFAR-12 41mm) are, but the Pentax Ultra Achromatic Takumar 85mm has a notch in terms of transmission. Then comes the UV-Nikkor 105mm and the newer CERCO 94mm; the newest and best being the most advanced development, the Coastal Optics UV-VIS-NIR Apo 60mm.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Monday, May 23, 2011

Bidens ferulifolia - visible, ultraviolet, bee vision

One of my "usual suspects" - Bidens ferulifolia shot using the newly converted camera.

[click on image to see a larger one]

VIS (using UV/IR Cut filter):


UV (using Baader-U filter):


BV (using my prop. XBV3 filter):



Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Saturday, May 21, 2011

[UV] Reflected UV photography and video - handheld

(currently being reworked)

[UV, VIS, NIR] WhiteBalancing options

Well, I had presented my Reflection Disc solution, which had been tested against (R) Spectralon when a forum member came up with the remark, that there are commercially available gray cards available, claiming to also work equally well in UV. So of course I got one and run tests against the industry standard (R) Spectralon as well as against my Reflection Disc (approx 75% reflection). That WhiBal Card has a white, a black area also, as well as a large gray area - all have been measured.

Long story short, here are the results.

[click on image to see a larger one]



SPECTRALON (100=rose, 50=violet, 25=teal, 12.5%=green); ReflectionDisc=blue, Whibal Card (white = yellow, gray=pink, black=red)

[confidence area: approx. 360 - 775nm]

SUMMARY:

That WhiBal card is certainly useful for VIS + NIR, but not for UV.

The ReflectionDisc certainly is not perfect, but works quite well in practice and delivers jpgs directly out of the camera with acceptable whitebalance for UV, VIS and NIR, also for a quick exposure check.

Here the photographic proof of the above - reflected UV using Baader-U filter and Xenon flash.



The card should be "white" or light gray, which it isn't. The cubes are Spectralon laying on my ReflectivityDisc.

It does work well in NIR though - here the card appears gray as it should be.



The cubes are Spectralon and my ReflectivityDisc stay the same color.


Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Thursday, May 19, 2011

UV Rain storm approaching

A rain storm was approaching today while I was shooting flowers; makes an interesting UV image!



Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Double Diptych : Bidens - Sanvitalia VIS vs Bee Vision

A diptych today, comprising a Bidens ferulifolia and Sanvitalia procumbens flower side-a-side in normal VIS and a bee vision (as seen through my one-shot propriatory XBV3 filter).



Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Friday, May 13, 2011

Some of my UV, simulated bee and butterfly vision work on exhibit....

So if you would like to see some of my work (updated 07 2017)


... and you live in North America, then you have a chance to see some here:

Honeybee research lab at Beaverlodge Farm, Agriculture and Agri-food Alberta, Canada 2017 Honeybee display presentation using Rudbeckia and Zinnia VIS-BV images

American Museum of Natural History, NY at Central Park forthcoming 2017 exhibit which includes the vision of butterflies using Rudbeckia VIS-UV-BV images

Zion National Park,  2017 visitor program on program on pollinators and their special adaptations  demonstrated on Rudbeckia VIS-UV-BV flower images

Highlands Center for Natural History in Prescott, AZ 2017 exhibit on guided naturalists walks demonstrated on various VIS-UV flower images

University of Pennsylvania, Center for Pollinator Research 2017 exhibit about pollination demonstrated on various VIS-UV flower images

Paplote Museo del Niño, México City  2016 exhibit about bees and pollination demonstrated on Bidens, Gazania and Sanvitalia flowers

Oak Hammock Marsh Interpretive Centre, Stonewall, Canada 2016 exhibit about animal senses demonstrated on Rudckia fulgida images

North Carolina Botanical Gardens at Chapel Hill 2015 and 2016 traveling exhibit on bees, pollination, UV nectar guides, demonstrated on Rudbeckia fulgida images

Hershey Gardens' new Milton and Catherine Conservatory, Hershey PA, 2016 exhibit about butterfly vision.

Anoka County Parks Minnesota, 2016 exhibit about butterfly vision demonstrated on  Zinnia and Gazania flowers.

Marine Discovery Center Florida 2016 Course about wildlife, regional ecology, and conservation

Roaring Brook Nature Center Conneticut  2016 exhibit about bee vision demonstrated on Marsh marigold - Caltha palustris

Minnesota Landscape Arboretum 2016 exhibit about bee vision demonstrated on Marsh marigold - Caltha palustris

San Francisco Science Museum, Golden Gate Park 2015 exhibit about Color incl. bee UV vision and pollination, opened June 12, 2015

New York Botanical Gardens, NY exhibit about bee vision

Longwood Gardens, Kennett Square PA exhibit about bee vision

Natural History Museum, Bolder CO exhibit about bee vision

Humboldt Coastal Nature Center, Arcata CA exhibit about bee vision and pollination


... and you live in Asia, then you have a chance to see some here :

Science Center Singapore 2016 exhibit about butterfly vision demonstrated on Gazania rigens in visible, UV and simulated butterfly vision


...and you live in the EU, then you have a chance to see it here:

National Media Museum, Bradford, UK 2017 exhibit about bee vision demonstrated on Gazania rigens in visible and UV.

Botanical Garden Erlangen, Germany  2016 exhibit using Bidens and Chelidonium to demonstrate UV nectar guides

Biosphere Kristianstad Water, Sweden  exhibit 2016 with images of Lesser Celandine flower in human vision, UV and simulated bee vision


Gasometer Oberhausen, Germany 11. March 2016 -  30 December 2017 "Wonders of Nature" exhibit with large size prints of Zinnia flowers in human vision, UV and simulated bee vision, as well as a video presentation of various flowers in VUS + UV showing hidden nectar guides

Carl Bosch Museum, Heidelberg Germany 12. September 2015 - 3. April 2016 exhibit about colors and dyes with a video animation with some of my best works in human vision, simulated bee and butterfly vision

Royal Botanic Garden Edinburgh - Tropism Exhibit video animation with some of my best works in human vision, simulated bee and butterfly vision

Natural History Museum, London exhibit about butterfly vision as part of the "sensational butterflies" exhibit, with Rudbeckia and butterfly images in VIS, BV and UV; still on display in 2017

Hortus Botanicus Amsterdam video animation with some of my best works in human vision, simulated bee and butterfly visio

All exhibits are different and were designed by the local authorities, whereas I provided assistance and advice as well as my photos.

I'm always happy to help raise the awareness about how beautiful yet fragile our nature is, so I guess that contributes a bit, especially as it also teaches the next generations to come.

Some impressions from the installation at The New York Botanical Gardens





Images (c) The New York Botanical Gardens

Friday, May 6, 2011