narrowing the beam of 3,5 or more led flashlight.

Hello, how to narrow beam of flashlight with several leds? for exmaple TR-j12. will it work with one convex lens ? or it need 5 individual lenses ?

it wont work with a single aspheric as that produces a pattern that looks a bit like a biohazard symbol on the wall when used with a 3 emitter flashlight. I tried it with the dry and a 60mm Aspheric for kicks. Might be good for the zombie hunting crowd. (Kind of a biohazard batman symbol).

If i throw away a reflector and replace original glass with this ?

is there any other project with lenses and leds in internet ? i can't find any.

There is, you'd need 3 seperate aspherics. Search for Viffer750's work.

or 5, for the OPs question

what diameter and shape lens need for tr-j12??

The Ledil boomerang works well in multi-LED apps:

These look promising as well; I'm planning on ordering some with the next Cutter order:

ordered this will try to create something :D