It's a gen1 after all - Armasight Spark CORE Night Vision Monocular

But your not gonna find a bigger bang for your buck in a Gen1 NVD. If you want better, save your pennies for a GEN2 or 3.
With that said, I had this unit out on a cloudy night and was testing it with, and without the built in illuminator. Detail without the illuminator was good out to 50yds. using it brightened things up a bit, and extended the range another 10 or 15yds. There is some fisheye but as has been said before, it's negligible. I couldn't be happier with this rig.