Jumping in here:

Sure, and everything I can type is readily available information and none of it is new - although it seems to be in danger of becoming forgotten information as more and more folks turn to light amplification devices - I have plenty of experience with those and they have their place. But I digress...

Caveat: Like making fire with friction, reading about "seeing in the dark" is absolutely not as good as being out in the dark with someone who can teach you.

OK - photopic, mesopic, and scotopic vision - fascinating stuff - let's call 'em "P", "M", and "S" for short.

P is daytime/ fairly high illumination and the cones do most, but not all, of the work. This is acute vision right in front of your focus. Cone = color vision and in this mode the rods main contribution is peripheral vision. You see color in front and B-W on the edges (your brain will be tricking you if you try to check this out, but you *can* prove it to yourself - no color available off on the edges - rods only come in one flavor)

S only uses the rods and they are completely absent in the center of your field of vision - that's retinal turf reserved exclusively for cones. So you have a total blind spot directly in the center of your field of vision that you use the most. Coping with that one issue effectively makes a HUGE difference for most people who feel that they simply cannot see at night. We'll come back to S in a moment.

M is relatively recently classified and explains away a few things that used to make folks like me go "Yeah, but sometimes I can see colors..." Essentially, M is a transitional mode that we use that involves enough light to stimulate the cones enough for our brains to notice but not so much that we totally overwhelm our rods. Deep twilight and early dawn are natural examples and for many of us, much more than a glimmer of moonlight on a clear night kicks this in. Without getting much into the color aspect of it, here's a simple test I use: If I can easily read a newspaper in moonlight, it's freaking bright out - for me, that's well under 50% illumination, but it varies from person to person. Proof that you are in M mode is that you can focus the print - S vision is horrible for acuity for obvious reasons. It also means that you've lost some of your dark adaptation, although it will come back more quickly once you get back into the gloom.

Bright moonlight (for me that means anything 1/4 or more) is fun while it lasts and I pay attention to moonrise/set/phase because while it knocks the snot out of my night vision, I can move through open areas as quickly as in daytime - YMMV, but it's awesome for everyone at some level of moonlight around 50% and up. OTOH, if there is a bright moon and you're mostly moving thru areas (like heavy canopy) where it's gloomy, the occasional patches of moonlight really screw you up. I have a really simple solution for dealing with that: I have an intense habit-turned-reflex to close my master eye tightly whenever light flares and only open it after the light dies out (bet you can guess where I developed that habit). One last thing - for M to really work in moonlight, you need to be in direct moonlight in all but highly reflective environments (like snow). Unlike daytime, there are pools of DARK under the trees... unless it's all snow covered and that's yet another topic in the saga (I have not found anything natural that's close to equaling snow cover, but others may know of similar environments).

See next post for more if interested.