The illness has struck hard, and I went from an Armasight Spark Core Gen 1+ to a Newcon NVS-7 2/3 Gen 2+.

I just used the Newcon for the first time on a pretty overcast evening. Now the NVS-7 is way brighter than the Spark, even when using in IR with the Newcon compared to the Spark with IR... and that's great. What I did notice was that when looking out to an empty field with little ambient light, the Newcon looked fuzzy/staticky, kind of like over the air TV reception once was when there wasn't a strong signal. Still clear enough to make details out at a distance, but there was a lot of static like motion if that makes sense.when I aimed it toward a street a few hundred feet away with more ambient light, it pretty much disappeared.

Is this normal?

I can't speak for that specific unit, but my eyes see all kinds of wonky shit through my 14s. Especially if you've been looking through them for a while, or you start getting tired.

I would sometimes see something similar to the static you are seeing, and very minor waves too. I noticed that was mostly happening over wide open, flat areas without much nearby. No trees, buildings, or real terrain features. I'm thinking maybe the tube is just picking up the light weird out to distance. If I bring the focus in close on the 14, it goes away.

Next time you go out, play with your focus adjustments, and also try to hit that areas that are giving you static with an IR light and see if they go away.

Totally normal in low light enviroments. Your tube is working hard. The technical term is scintillation.

Indeed. This was a surprise to me too when first seeing through a Gen2 unit after briefly having tried a few Gen1. Gen1 had a clean image, though dimmer than the dark adapted eye, and Gen2 looked like a bad TV signal. With Gen3 (or higher end Gen2+) it's a lot less noisy.

At low light levels of photocathode illumination, image intensifiers which are capable of very high gain figures are limited by the finite number of electrons released at the photocathode.  at these very low light levels, the tube is no longer able to create a continuous image , but rather the image becomes broken up into individual scintillations. each individual scintilation seen accounts for each individual electron released at the input photocathode. there is a minimum number of percievable flashes required for the eye to be able to resolve a continuous image.

So its very similar to the old CRT TV with bad signal reception. When the signal is to weak the TV's CRT tube output screen can only form a broken image on the screen because the signal is not strong enough to allow for a continuous image to be resolved. Hence the fuzzies you start to see more and more of as the signal reception gets worse and worse.

So more ambient light, stronger signal, less scintillation... I think I'm following.

Hoping tonight is clearer skies with more moonlight and starlight to see the difference.

Now I want Gen 3!

Oh well, through a trade I got into a better unit than my Spark much quicker than I hoped, so I'm running down the right path.

Yup more light = better image.

Also, jumo from gen2 to 3 wont be as big as going from the spark to gen 2.

OP is rocketing down the rabbit hole. He’ll have 31’s in WP by next year at this rate.

I'm not even going to look up what those are!

PVS-14 white phosphour is my next planned upgrade.