Fast14riot
Gold $$ Contributor
I like your flair of the dramatic for sighting situations. Love the post.
You're absolutely correct about polarizers being 1 or 2 F-stops. As I was explaining to someone in a private DM exchange earlier, the difference between what works in photography and what would work for the mark 1 eyeball, is the fact that in photography, we have better exposure control. We have aperture control, shutter speed, and ISO. If I reduce the aperture, I can decrease the shutter speed to make up for it, or I can change the ISO (sensitivity), or a combination of both, and still have correct exposure. The reasons for reducing aperture would be to get greater Depth Of Field (DOF). If I use a polarizer, I do not get greater DOF, I just get less light to the sensor or film, and I make it up with the shutter speed of the ISO.
In a riflescope, reducing the aperture will increase the DOF, but you can't increase the shutter speed. The "ISO" will change as your pupil dilates but that takes a bit of time and only goes so far, especially for old geezers.
Top end optics have methods for controlling lens flare built-in. Over at Snipershide, the Dark Lord of Optics, keeps reminding everyone that March has the best flare control of all the scopes he's tested, and you can use a sunshade if you get too close to the sun when aiming. Point being, I don't think it's worth the 1 to 2 stops (50% or 75% reduction on light) into the riflescope to deal with something that's already being addressed.
I tried some circular polarizers for my Kowa 82SV, and it just made everything darker and brought in nothing that I could detect. I have circular polarizers for a few of my camera lenses, they provided for some dramatic pictures when I was shooting 35mm film, but it's been a quarter century since I've shot film. Nowadays, we can simulate polarizers in PP for digital pictures, and apply as little or as much as we want. (Crap, before I forget: PP = post processing, photoshop.)
I have come to the conclusion that I want absolutely nothing to (further) distort the image that comes from the eyepieces of my eye-wateringly expensive riflescopes. That's why I am so impressed with the Trivex stuff. I cannot discern a difference between naked eye and Trivex glasses.
Please continue to share your findings and experiences.
Apart from the dimming of light, something I have yet to find a paper on is the use of a polarizer not in front of the optical train, but in my glasses. The biggest difference between film/sensors and our eyes is HDR (high dynamic range) is unmatched by image capture systems. Our eyes (brains actually, eyes are just lenses) can see a far wider dynamic range than able to capture, so losing the couple stops makes things worse for film or sensors. (Dynamic range is ability to see detail in shadows and bright light at the same time.) I do have an aperture for one of my scopes, have yet to play with it, but this may be an added column for some testing. It will all be anecdotal, of course. My eyes, my vision, but will try to remember to bring my light meter (or a couple of them) to get some baseline numbers that could be repeated if required.