Beam Expander DIY Cons

What are the cons of using a monocular as a beam expander ?

Ive seen some threads on those who use Monoculars as beam expanders and it seemed like it worked well for them .

But does it really take up a lot of light and power? How is it compared to a real Beam expander?


PS. They took of the PRISMS (?) in the monocular and made use with the 2 lenses in the monocular. Wondering if it works with this

Problem is, unless someone here has purchased that same unit and found they could remove the prism without too much trouble, you won't get the answer you seek. I bought another one somewhat similar to that and left the prism in but the loss was far too high, I could really see a much dimmer beam. It should work either way, just dimmer if you can't get it out.

I got a decent 8x one thats focsuable and lets most of the laser light through.