Originally Posted by seeker333

I grabbed the first piece of red plastic i could find for the quick test - a lens off an old cateye tail light, which was wide enough to cover the 40mm diam lens.

Obviously a nice round 41 mm lens would be better, ideally one with threads to fit the flashlight. I wonder if there are any useful inexpensive filters out there in photography world. Hey I think I got a couple that are ~55mm, for the old FILM slr. Maybe I'll try those.

I don't think you'll get a dinotte-like red light regardless of filter you use - the blue component of the P7 lights seems to turn red-filtered light into an orange-ish color. Which is probably OK anyway. And still less then 1/3 cost of a dinotte tail light, with additional benefit that it can be used as a flashlight.

Please let me know if you find anything.

Originally Posted by ElJamoquio

Forgive my ignorance - but if I purchase regulated batteries, I don't need a regulated flashlight, correct?

Originally Posted by Ziemas

The batteries aren't regulated, they are protected. Regulated means that the light output is more or less constant throughout the charge of a battery. Protected means that the battery itself shuts down if it's over charged or under discharged.