6mm, apologies as I just saw your question just now. I can see well with the Gen2 (for navigating/walking) but yes I do need the illuminator most of the time. If the moon is out, I can manage ok, but it's much easier with the illuminator. You don't need an expensive one since I only need it to shine 50 yards max....but if you want it more for identifying predators out in the field, I would say you might want Gen3. Hope that helps!
