These things have a very high resolution and should be good out to a few hundred yards for larger targets. Give up on the idea of using it without an illuminator. I have a very cheap Nightfox digital binocular style night sight and it works very well for what it is. It can work with visible or IR light, using visible light it needs more light than my bare eyes. Starlight scopes need no IR light as long as your target is exposed to star or moonlight. As far as I know no digital night scope can claim that.
Starlight scopes were early gen 1 NVG’s and would definitely benefit from an IR Illuminator.
Higher end options, like the PVS-9, 22, 27 will perform better with their big lenses they bring in more light to the intensifier.