ashbucket, to be honest, mine came in the kit and I haven't used it without it. I like it more for not illuminating my barrel and myself with spill-over light. I ran a big homemade filter on my Q-beam handheld for the same reason when I used it. Really had nothing to do with seeing better, just kept me from being seen as easily.
As for the night time ID part, there is no solid answer for that one. There are a lot of factors in how far you can truly ID an animal and each persons definition of what they call ID are different. Weather conditions like humidity, temperature, wind, precipitation, and things like terrain and the shooters eyesight will all be factors. Where I hunt, I've called in a bear, cows, deer, barn cats, a beagle, a labrador retreiver, and the neighbors wife plus red fox, grey fox, and coyote. A hard charging grey tabby and a grey fox look a lot alike at night with a red LED. A german shephard and a coyote aren't much different either. For me, I like to keep my shots under 100yds just to make sure. I also like a little time to watch the animal's walk and their behavior. Just looking at one or the other usually makes me a little uncomfortable when shooting at night. I usually try to setup in areas where I can't see much farther that way I can try and funnel them into that 100yd comfort range with my calling.
