Wednesday, April 8, 2015

How the sun sees you - human skin and sun blocker effect as seen through reflected UV photography II

Today more about how the sun sees us and how bees might see us in UV. Well, in other words: how does human skin look like in reflected ultraviolet (UV) light compared to normal human vision. After shaving every morning, I usually apply some day cream to protect my skin. Shots were done inside using a modified for UV Xenon flash. A UV capable lens was used for this. All shots were done at about f5.6.

[click on image to see a larger one]

BW human vision VIS image (left), bw UV image (right)

So, the sunblocker in my daycream obviously has protective effects, clearly visible by the darkened skin. This shows that the used cream absorbs dangerous UV-B and also UV-A radiation (the latter being important to protect against the so called "white" skin cancer). Further its gets visible, that the reflected UV image clearly shows otherwise invisible freckles, about which some dermatologists say that it is skin damage getting visible, caused by the accumulated UV radiation exposure over the years. So whenever you're out in the sun, protect your skin!

To summarize, I would say that reflected UV photography is a very suitable tool to make all that so nicely visible!

I have written about that HERE before.

There is also a corresponding video about that topic HERE

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

Sunday, November 16, 2014

Enhancing the visibility of fossil tissue structures using UV reflected and UV stimulated visible flourescence photography

A while ago I had the honor to work with Neal Larson on a paper on fossilized cephalopods found in Hajoula, Lebanon. Today it is again about enhancing the visibility of fossil bone and tissue structures using UV reflected and UV stimulated visible fluorescence photography, but as it is some years later, using more modern equipment now. I will also use my remapping technology consisting of a visible image, a reflected UV image and an UV stimulated visible fluorescence image and combine them into multispectral images.

Lens used was my CERCO f4.1 / 94mm quartz fluorite lens, light sources were a modified high power Xenon flash, as well as a NICHIA 365nm Power LED. Target was a fossilized fish from Solnhofen, Germany, approx. 100 Mio years old.

[click on image to see a larger one]

Visible light image using UV/IR Cut filter:


Reflected UV image using Baader-U filter (310-390nm): 


UV stimulated visible fluorescence (FL) using Nichia 365nm UV LED:


Combined VIS - FL multispectral image: 


Combined VIS - UV multispectral image::


Combined FL - UV multispectral image::


It gets nicely visible that using UV light photography brings out much more details than normal visible light photography and by doing so, enhances the visibility of preserved bone and tissue structures quite a bit. Combining those different images into falso color multispectral images  enhances the structures even more.

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, September 17, 2014

How the sun sees you and how the bee sees you - human skin and sun blocker effect as seen through reflected UV photography

Today about how the sun sees us and how bees might see us. Well, in other words: how does human skin look like in reflected ultraviolet (UV) light and in simulated bee vision (BV) all compared to normal human vision. Sun blocking cream has been applied to the right side of the face to show which impact that has. All shots were done outside using sunlight. A UV capable 35mm lens was used for this. All shots were done at about f5.6.

[click on image to see a larger one]

Color human vision VIS image (left), false color UV image (right)


BW human vision VIS image (left), bw UV image (right)

Aside from the striking impact that SPF50 sunblocker has, it gets quite obvious, that the reflected UV image clearly also shows the UV pattern a Rudbeckia fulgida flower has. Human skin in UV shows otherwise invisible freckles, about which some dermatologists say that is skin damage getting visible, caused by UV radiation. Further to that, the otherwise invisible front tooth repair also gets nicely visible.

P.S.: my polo shirt massively reflects UV around 365nm - that is for the UV nerds only :LOL:

So what would a bee see of that I got asked. Well, let's see...

Color human vision VIS image (left), false color UV image (middle), simulated bee vision BV (right)

So the bee vision (BV) image also shows the effect of the applied sun blocking cream, as well as the flower UV patterns. It is not as striking as the bw image, but what do we know, how a bee really sees us...

So to summarize, I would say that reflected UV photography is a very suitable tool to make all that so nicely visible!

There is a corresponding video about that topic HERE


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

Tuesday, September 16, 2014

Making of Thomas Leveritt video "How the sun sees you" - reflected ultraviolet (UV) photography part I

Well, in August 2014 a video "How the sun sees you" by Thomas Leveritt went viral on the net, a video about using sun cream for skin cancer protection and raising awareness about the need for skin protection. Leveritt used materials and techniques which were known by UV photographers since many years and my readers here have seen my older videos which employed the very same techniques, however used to make visible what bees, butterflies and other insects see and we cannot - ultraviolet (UV) light. Usually I use a false color palette to make UV visible.

Have a look at the following HD black+white video clip to see that it is indeed doable. I would like to show in part II later that such a video can be made using a suitable camera, lens + filter.




Now the following is the same HD video clip, but this time in false UV colors. They have a meaning, but this might be revealed later on.


I hope you enjoyed this funny little clip 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, August 13, 2014

150mm Micro reproduction lens for reflected UV photography

Today about a recent find for UV photography, a high resolution (approx. 150-200 lpm) 150mm micro documentation lens, which I have tested positively for UV use. Of course it shows quite some restrictions, but I'm happy about finding such lens in such longer focal length (150mm), which allows for better working distance in some circumstances. All shots were done it studio. Lens for comparision was my CERCO 94mm quartz fluorite lens. Light source was a Xenon flash. All shots were done at about f8.

[click on image to see a larger one]

Test images using Baader-U filter for reflected UV photography and as a target a Rudbeckia fulgida flower. Adjusted for comparison to even out focal length differences. Individual white balance set per image.

Cerco 94mm (left), Micro Documentation lens (right)

The micro docu lens does quite well and seems to be quite a sharp lens, even when used for UV.

Now about the spectral transmission:

It gets obvious that this micro docu lens only transmits down to about 350nm, but has sufficient transmission around 360nm to make flower UV patterns visible.

So to summarize I would call that a nice find, which adds to the repertoire of suitable UV lenses, especially since it has very high resolution also in UV.


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

Tuesday, August 5, 2014

City of Manchester "Dig the City" focusing on Honey Bee - UV and simulated bee vision photography

The city of Manchester is having their "Dig the City" urban gardening festival again this year 2014 (2-10 August 2014) supported by the National Trust. The Honey Bee is the sign of the city and it may bee seen all over the city of Manchester. Actually the festival is going on right now as I type this!

This years focus lies on the rapidly decreasing honey bee populations in the UK and worldwide and what each person can do to help. I have contributed some of my work to that, still photography in VIS and UV, as well as in simulated bee vision, which may be seen in use on the following twitter picture which has just been published:
That flower shown is Zinnia angustifolia, which I have written about it before HERE.
 

So if you are close, consider a visit, it's quite worth it!

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

Sunday, August 3, 2014

BBC Hive Alive - series about the life of honey bees including UV photography

BBC2 has receently produced a new two episode series "Hive Alive". This two-part documentary in is presented by Chris Packham and Martha Kearney, assisted by Prof. Adam Hart reveals the mysteries of the honeybee.

As it has already been aired in the UK only, here the link to it on youtube, which starts with the most interesting part here, as it is about the bees ability to see in ultraviolet (UV) light and the UV nectar guides some flowers have developed during evolution.

I have contributed some of my work to that, still photography in VIS and UV, my loyal readers will notice them, as I have shown them before HERE. Prof. Lars Chittka, whom I work with, presents his scientific findings and my works are seen there combined with his and his videos form 28'10" onwards. Here is the link in case the embedded video does not work. Ideally watch it directly there fullscreen, as it is HDTV.


There is a 2nd episode, but it hsn't been uploaded 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