How 'bout that. Just came in from the mailbox with MY ducky luck laser. Perhaps I'll try lighting up a cloud bottom tonight. Unlike Seth I don't have a basis for comparison, since this is the only laser pointer I've got. I do see noticeable beam spread, with the beam perhaps an inch across at 50 feet or so (that's not a formal measurement). Is that about what I should expect? On Dec 18, 2006, at 4:37 PM, Seth Jarvis wrote:

My LuckyDuck laser just arrived. Very nice! It came in a nifty padded travel case with a couple of AAA batteries so I was able to fire it up right away.

Couple of points on green lasers. There are not that many diode manufacturers. Many different pointer brands actually use the same model diode. That said, each diode manufacturer has several models of differing output power and beam divergence. The pricier the diode, usually, the better the beam quality and brightness. My Beta pointer has a tight, round beam. My non-optimised laser has a pretty tight beam as well but is less than half as bright, to the eye. If your dot displays funky artifacts, try blowing out the lens with canned air (or compressed air from a non-oil-lubricated compressor). Often it's just lint or dust on the exit window that cause diffraction aritfacts. You can remove stubborn dirt with a Q-tip dampened with lens cleaner (not sopping wet, just damp). Follow-up with a clean, dry Q-tip. Changing brightness is usually an indicator of a poor power connection. Clean the battery terminals, or clean the switch contacts. The switch contacts themselves may be just contacting each other poorly. If fixing connectivity problems doesn't cure the variable brightness, the diode may be damaged. One of my early laser experiments was an off-shoot of the visibility test Ann House and I performed. I mounted the laser on the telescope and aligned it with the center of the field of a high-powered reticle eyepiece. By just aiming the crosshairs on the target, the laser was aimed as well. But a benefit is that you can attach a linear scale on a distant post and then see the dot size through the eyepiece without having to leave the laser on and walk down to the target. Leaving a green laser diode on for an extended period can damage it permanently- it may stop functioning or become permanently dim. Especially the 5mw optimised units, use them intermittently only. If the beam is too bright to accurately judge the diameter, a ND filter attenuates the beam sufficiently. Anybody want to compare dot size along with beam visibility? --- Seth Jarvis <SJarvis@slco.org> wrote:

I own two other green lasers, and this has the tightest beam of the lot. No funny blotches around the perimeter of the (killer bright) green dot and the beam seems rock steady. One of my other two green lasers' beam jumps around quite noticeably in brightness, and its sibling has a steady beam but is not especially bright.

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