burning laser lens

So for my first build instead of buy I am building a 405nm laser, I have the host picked, the laser aperture from dtr picked out. And all the setup but one piece figured out. The lens... my goal with this is to try to pop black balloons at 50+feet and this brings me to where I need some help from all of your guys experiance... what would be the best lens choice to make the feat possible? And also if I put a 10x zoom lens on it will it be able to burn farther?

Try this.

Lase

thats one option I am going to try after looking in the forums i've got a few different idea's to try and I will post some findings when I have some time to sit down and do some testing. Now just to finish looking up here on how to build to LPM for measuring laser power at different distances.

Laser power is always conserved... it's just the power density that changes. The beam will get larger, but it still contains the same power within it, just more spread out.

I did not know that, thank you wolfman for that info.