Collimator lense - question

Hi guys!

I have a question about the collimator lenses.. With my red DVD LDs i used a collimator lense from a cheap laser pointer..

I could get it focused into a nice spot, but i noticed A LOT of the light coming out of the LD is getting lost, due to it going around the lense..


Does that mean i have a bad collimator lense or is this normal?

It looks like a big loss of power, that should be going into the beam...


Are other lenses better at this? Or are there even different - double lense arrangements, that first collect all the light and then pass it on to the collimator?

I'm sorry if it's a stupid question, but i need to know.. Is this normal, or should i get a better lense, for example with the Aixis module?


Thanks!


Igor

Get a larger diameter positive focal length lens. Problem solved