[Xrundel]

Arclight, buddy - I never had any intentions to upset you or feel bad. You did very good job transforming stock periscope into something much better and more historically accurate. You've made a mod and people are free to decide if they want to use it or not, correct? I installed your "regular" version of your mod first and I started historical mission that set up in clear day at 12 o'clock.
It looked to me like midnight with full moon. I even checked the clock on user interface. And this is all I was trying to say. I install your "light" version and naturally ask myself why you even needed to come up with "light" if everything is the way it suppose to be, but it does not matter. I found better solution and happy with it. It also have darker attack periscope compare to observation but it looks more natural to me. And it's only my opinion. And you have all rights to have yours. You like mathematical formulas and apply them to figure out outcome? That's very good, my friend. But if outcome is not exactly what it really is in practice - then maybe some input values are wrong or there is simple error in calculation. Such an errors cost NASA extra trip to Hubble on near-Earth orbit. If NASA can do it - I think every one else can .
If you still insist that you have absolutely correct brightness interpretation in your scope mod - fine with me - my life won't change a bit. Maybe later in you life you will have opportunity to look through real periscope and that will be much better than thousands words from me or anybody else.

Now to quotes:

Think I got it close enough for someone who has no education in or experience with optics.

You got it very close indeed, very good job! Especially darkening optics towards the edges.\, where light losses are greatest.

You're avoiding the point I was trying to make: you can't compare a telescope to a WWII submarine periscope.

I was not avoiding this point. Probably I was not clear enough with my bad English. You CAN and you HAVE compare periscope of any historical period with the telescope. Because as long as there is magnification (1.5x and 6x as you know) it is long focal distance refractor with added two mirrors/prisms on it's optical path to bend it 90 degrees twice. You can call it viewing pipe, periscope, telescope, half of binocular spotting scope - it is refractor and principal is absolutely the same with only difference that telescope refractor can change eyepieces for more powerful ones(with shorter focal length) boosting magnification to hundreds x but accordingly reducing brightness of the image. So - less magnification - brighter image.

So if you know how to make the scopes more realistic, I'd gladly hear it.

In my opinion (that you can just ignore if you want) rename "light" version into "regular" and make another slightly lighter - "light" and that would be more realistic. Just answering your question - I know you are not going to do anything.

And by the way - if TDW uses your version as default in his UI - it looks just fine. Maybe I've downloaded some original release that was much darker and all this talk here just as pointless as it could be.
With your permission I would leave this discussion - I really don't want wake up one morning and see that I have almost 32 thousands posts on some forum - I actually have a life.