What I have found with my no-peep over the last few years is that, as Timberline states for their fiber-optic sights, it works best in natural light. I have one of their sights and their no-peep. I can see both outdoors in almost no light, which would happen at the early and late end of shooting time. However, in an archery shop it isn' t as easy to see because the light bulbs don' t illuminate them as well. Going into a closet will NOT test what you are looking for. Although I haven' t tried it, I suspect that the no-peep would work fine in a blind. I have gone outdoors when it was almost totally dark and been able to shoot fine using the no-peep in order to check how it works at low natural light. Under those conditions I can use it under much less light than I can see a peep.