1W 638 or 2.5W 450??? Need Advice!

BowtieGuy said:

Correct me if I am wrong, but you may not want to use an acrylic lens with a 1W 638nm, at least not for very long.

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As long they are focused to infinity there is no risk but when focusing to a pinpoint you will get the housing melted.

So for static focused builds there you can also use acrylic as well but I also prefer glas lenses because they can be cleaned easier and do not get scratched that easy.

I will be using a 40 or 50mm Glass Lens from Thorlabs.

BowtieGuy said:

Correct me if I am wrong, but you may not want to use an acrylic lens with a 1W 638nm, at least not for very long.

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I wonder about that though... there are some AR-coated acrylic lenses that might be pretty good. The lenses were never AR-coated for blue and violet, and the absorption by the acrylic itself, which starts becoming opaque around violet, might cause problems. Still, the beam of that red diverges so quickly that it might start melting the plastic.

You're probably right about the higher quality acrylic lenses being available.
I guess my response was based on my personal preference for a glass lens.
I think if I were to want to improve, or correct the Mits. beam, I would look at other options first, rather than take a chance with the plastic.
I also like to keep focusability as an option, even if it's focused to infinity 90% of the time.