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Most cheap (sub-$100) laser collimators I've seen are like this. This includes a GSO one I bought a while ago. They seem to lack a proper circular mask. The laser diode itself yields a rectangular shaped beam.
Maybe the cheapies do have a mask but it's not properly cut or easily dislodged. Compared to my Glatter collimator (which has a detachable mask) the elongated beam shape of the GSO isn't even sharply defined but fuzzy.
IIRC, there has been a thread on IIS recently about fitting a DIY mask to GSO and similar collimators.
Cheers
Steffen.
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