Many birds can see UV. How do their eyes handle it? People living in northern countries have more occurrence of non-brown eyes, ie blue or green or gray. Are they more adapted to these snow covered conditions?
How can we make a digital camera take a picture in ultraviolet. There are ultraviolet filters around but they remove the UV light. Are there filters that let UV in and block all visible light available to screw onto cameras?
"How can we make a digital camera take a picture in ultraviolet. There are ultraviolet filters around but they remove the UV light. Are there filters that let UV in and block all visible light available to screw onto cameras?"
Filters that pass UV but block visible light are available (& you should be able to find mounted filters that fit your camera)*. Ex: http://www.maxmax...rder.asp
*note that you may need to add an IR blocking filter[ http://www.maxmax...ters.htm ] to the stack to produce UV-only images.
People living in northern countries have more occurrence of non-brown eyes, ie blue or green or gray. Are they more adapted to these snow covered conditions?
Blue eyes were a random mutation that was selected for 10,000 years ago near the Black Sea. It's a coincidence that the ancestors of those tribes moved North. The Inuit all have brown eyes.
PPihkala
May 26, 2011People living in northern countries have more occurrence of non-brown eyes, ie blue or green or gray. Are they more adapted to these snow covered conditions?