"Photo Gray" was the name given to the first lenses used in eyeglasses what would darken when exposed to sunlight. It was invented by a German named Dr. Jurgen Meyer-Arendt. In his later years he was a professor of optics at Pacific University School of Optometry. Prior to that he had been a neuro surgeon in Germany just after WWII ended. He was also a mountaineer a climbing mentor of mine.
I thank all of you for your thoughtful responses with solutions, many of which I had not thought of. I believe a LED cube light that attaches to the hotshoe will work well. I did not know they existed. Because the light will be directional to the subject I'm shooting (rock art), the light does not have to shine 360 degrees, which would be the case if the lighting device had to sit on the ground. It also allows both hands to be free to operate the camera. There are places where I will be lying on my back shooting rock art on low ceilings.
Definitely better than a beam, but does not put out much light vertically.
I will be going into a cave to photograph rock art. Flashes are not permitted, but flashlights are. Do you know of a flashlight that puts out roughly 360 degrees of white light? I have the usual LED flashlights that put out a beam.
Better check out Abes of Maine, a search for it in the forum may give you hesitation - grey market etc.
My Nikon D7200 has a Nikon GP-1A GPS unit mounted on the hotshoe. It works beautifully, but it records coordinates as WGS 84. All of my USGS 7.5 quads are NAD 27. It is an absolute pain to manually convert WGS 84 to NAD 27. The camera menu has a "position" screen, but no way to convert to NAD27. Do you know any way to deal with this besides manual conversion? Thanks.
I never got to shoot much Kodachrome 25 when it came out. The colors were quite different from Kodachrome 12, so my family and other local photographer friends switched to Agfachrome
Thank all of you so much for taking the time to give me guidance on good third party literature for the Sony a6000. The Sony manual just isn't what I've been accustom to. I will use the camera only for landscape shots taken while hiking. When I get to my destination(s) I will break out from my pack the Nikon D7200 and the lenses I need to photograph my specific subject matter. Thanks again!
If you shot Kodachrome ASA 12, you know where I come from. I'm pretty comfortable now with my Nikon 7200, assorted lenses, shooting RAW and PP with Lightroom. I need to carry my DSLR and big lens in my pack now so it's not swinging around my neck. Stability hiking problems at 74. So I've ordered a Sony a6000 to carry in my shirt pocket (I know, I'll enlarge the pocket). So I download the 478 page manual. There is no Index. Ok, I know there is a Find function in Acrobat. Somewhere in that 478 page manual there must be a camera, with shutter speed, aperture and ASA ( sorry, ISO). I guess I need to keep my brain active.
What does the red dot do to the eye of the bird? Is it a laser? Airline pilots get blinded by laser beams.