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bino viewers
by Kim Hyatt 12 Aug '03

12 Aug '03

Hey all you smart folks - isn't it possible to build a quality bino viewer from off-the-shelf stuff? I've been intrigued by bino viewers since I first saw one 11 years ago at RTMC. However, the cost has always been prohibitive. I don't know enough about optics to be able to figure it out, but if anyone else can, let me know. Kim A. Hyatt, AIA SL&A Architects 331 South Rio Grande, Suite 304 Salt Lake City, Utah 84101 Tel: 801.322.5550 x122 Fax: 801.322.5557

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RE: [Utah-astronomy] Green laser backlash
by Kim Hyatt 11 Aug '03

11 Aug '03

Brent, in what classes do both red and green lasers fall? -----Original Message----- From: Brent Watson [mailto:brentjwatson@yahoo.com] Sent: Monday, August 11, 2003 3:36 PM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Green laser backlash The following is from CFR 21 part 8 section 1040.10 (b), where these things are codified and damage limits defined: (5) 1 Class I levels of laser radiation are not considered to be hazardous. (6) 2 Class IIa levels of laser radiation are not considered to be hazardous if viewed for any period of time less than or equal to 1 x 10\3\ seconds but are considered to be a chronic viewing hazard for any period of time greater than 1 x 10\3\ seconds. (7) 3 Class II levels of laser radiation are considered to be a chronic viewing hazard. (8) 4 Class IIIa levels of laser radiation are considered to be, depending upon the irradiance, either an acute intrabeam viewing hazard or chronic viewing hazard, and an acute viewing hazard if viewed directly with optical instruments. (9) 5 Class IIIb levels of laser radiation are considered to be an acute hazard to the skin and eyes from direct radiation. (10 6 Class IV levels of laser radiation are considered to be an acute hazard to the skin and eyes from direct and scattered radiation. For the complete text, got here: http://www.lasersafety.net/CFR/cfr_title21_part1040_10.html Brent --- "Lambert, Aaron" <Aaron.Lambert(a)Williams.com> wrote: > Hello all, > Just delurking here for a moment... For those of > you who > own green lasers already, where have found the best > place > to purchase them are? The best price I have seen is > EBay > for around $70. I always wonder about the quality, > etc of > EBay items that are mass-sold, though. I have > considered > buying one so it is easier to point out > constellations for > my kids (ages <= 6) and for youth groups (ages > between 12 > and 18). Pointing with my finger works pretty well > for > showing one or two people, but I have tried that > while > camping with a group of 10+ and they cannot all > follow my > arm and finger very well. > Also, I understand that they are fairly dangerous > in > that they can cause severe eye damage if the beam > hits > someone in the eye. Is this true? Obviously I > wouldn't > intentionally let a kid (old or young) get a hold of > one, > but I remember being fairly curious and resourceful > as a > teenager... :) Anyway, I would appreciate any > comments or > insights from the group. > > Thanks, > Aaron Lambert > > _______________________________________________ > Utah-Astronomy mailing list > Utah-Astronomy(a)mailman.xmission.com > http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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RE: [Utah-astronomy] Green laser backlash
by Lambert, Aaron 11 Aug '03

11 Aug '03

Hello all, Just delurking here for a moment... For those of you who own green lasers already, where have found the best place to purchase them are? The best price I have seen is EBay for around $70. I always wonder about the quality, etc of EBay items that are mass-sold, though. I have considered buying one so it is easier to point out constellations for my kids (ages <= 6) and for youth groups (ages between 12 and 18). Pointing with my finger works pretty well for showing one or two people, but I have tried that while camping with a group of 10+ and they cannot all follow my arm and finger very well. Also, I understand that they are fairly dangerous in that they can cause severe eye damage if the beam hits someone in the eye. Is this true? Obviously I wouldn't intentionally let a kid (old or young) get a hold of one, but I remember being fairly curious and resourceful as a teenager... :) Anyway, I would appreciate any comments or insights from the group. Thanks, Aaron Lambert

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RE: [Utah-astronomy] Green laser backlash
by Kim Hyatt 11 Aug '03

11 Aug '03

It has since occurred to me that perhaps green is more dangerous because our eyes are more sensitive to green light, given the same power/wattage. -----Original Message----- From: Don J. Colton [mailto:djcolton@piol.com] Sent: Monday, August 11, 2003 12:47 PM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Green laser backlash Eye damage can occur with green lasers. They are more dangerous than red ones. I read about an amateur astronomer causing some problems with a friend's eye when he was trying to collimate a scope with a green laser. You eye's involuntary closing should help some but it isn't 100 percent effective. Clear Skies Don Colton -----Original Message----- From: utah-astronomy-bounces(a)mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com]On Behalf Of Kim Hyatt Sent: Monday, August 11, 2003 11:00 AM To: 'Visit http://www.utahastronomy.com for the photo gallery.' Subject: RE: [Utah-astronomy] Green laser backlash Regarding sources, I can't help much. I paid too much for my green laser at RTMC, but it has built-in red and white LED lights, as well, so the cost was offset somewhat. It was a bit of a compulsive purchase, I must admit. I also wonder about eye damage. Since the maximum output is supposedly the same as for red lights (5ma) how would a green laser be any worse than the red? -----Original Message----- From: Lambert, Aaron [mailto:Aaron.Lambert@Williams.com] Sent: Monday, August 11, 2003 10:55 AM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Green laser backlash Hello all, Just delurking here for a moment... For those of you who own green lasers already, where have found the best place to purchase them are? The best price I have seen is EBay for around $70. I always wonder about the quality, etc of EBay items that are mass-sold, though. I have considered buying one so it is easier to point out constellations for my kids (ages <= 6) and for youth groups (ages between 12 and 18). Pointing with my finger works pretty well for showing one or two people, but I have tried that while camping with a group of 10+ and they cannot all follow my arm and finger very well. Also, I understand that they are fairly dangerous in that they can cause severe eye damage if the beam hits someone in the eye. Is this true? Obviously I wouldn't intentionally let a kid (old or young) get a hold of one, but I remember being fairly curious and resourceful as a teenager... :) Anyway, I would appreciate any comments or insights from the group. Thanks, Aaron Lambert _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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RE: [Utah-astronomy] Green laser backlash
by Kim Hyatt 11 Aug '03

11 Aug '03

Regarding sources, I can't help much. I paid too much for my green laser at RTMC, but it has built-in red and white LED lights, as well, so the cost was offset somewhat. It was a bit of a compulsive purchase, I must admit. I also wonder about eye damage. Since the maximum output is supposedly the same as for red lights (5ma) how would a green laser be any worse than the red? -----Original Message----- From: Lambert, Aaron [mailto:Aaron.Lambert@Williams.com] Sent: Monday, August 11, 2003 10:55 AM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Green laser backlash Hello all, Just delurking here for a moment... For those of you who own green lasers already, where have found the best place to purchase them are? The best price I have seen is EBay for around $70. I always wonder about the quality, etc of EBay items that are mass-sold, though. I have considered buying one so it is easier to point out constellations for my kids (ages <= 6) and for youth groups (ages between 12 and 18). Pointing with my finger works pretty well for showing one or two people, but I have tried that while camping with a group of 10+ and they cannot all follow my arm and finger very well. Also, I understand that they are fairly dangerous in that they can cause severe eye damage if the beam hits someone in the eye. Is this true? Obviously I wouldn't intentionally let a kid (old or young) get a hold of one, but I remember being fairly curious and resourceful as a teenager... :) Anyway, I would appreciate any comments or insights from the group. Thanks, Aaron Lambert _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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RE: [Utah-astronomy] Green laser backlash
by Paul Witte 11 Aug '03

11 Aug '03

Well, I just ordered one, so I hope not. :) I don't personally know anyone who does serious imaging at a public star party, that doesn't really sound very practical anyway. I can see how it might be a problem at private star parties, but public star parties are probably the only place I would ever use one. I can't think of a better way to show newcomers exactly where things are. I find a lot of the general public have a hard time looking through a telrad for the first time. Still, it's probably a good idea to just ask people's opinions at the beginning of the star party and obviously try not to intrude on areas of the sky other people are observing. It certainly wouldn't bother me for them to be in use at a public star party. ---------- From: Chuck Hards Sent: Sunday, August 10, 2003 10:11 PM To: Utah-Astro Subject: [Utah-astronomy] Green laser backlash I've read recently of a growing scorn of green laser pointers at star parties, due to their rapid proliferation and easily-seen beam. It seems that so many people are using them that other observers are beginning to speak out against them as light pollution on the field. Especially imagers & astro-photographers. I've been hankering for one of those for a long time, but if it's going to irritate people, perhaps I'd better not. Have any list members experienced this? Is this just at the large, regional star parties, or are camps pro & con forming up at the local level? Particularly would like feedback from owners & frequent users of green pointers. Thanks! Chuck __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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RE: [Utah-astronomy] Mars
by Kim Hyatt 11 Aug '03

11 Aug '03

Thanks, Chuck. Glad to hear I was probably not just imagining things. -----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Monday, August 11, 2003 10:35 AM To: utah-astronomy(a)mailman.xmission.com Subject: Re: [Utah-astronomy] Mars --- Kim Hyatt <khyatt(a)smithlayton.com> wrote: > Anyone else had a similar > experience? The BEST Mars opposition for me was 2 or 3 oppositions ago, when it was high in a spring sky. I used powers of 400x-500x regularly, and saw morning hazes on more than one occassion. Haven't seen one at all this time around, unfortunately. C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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Mars
by Kim Hyatt 11 Aug '03

11 Aug '03

I've been out of town a lot recently and have not had the time to report an interesting observation of Mars I made early in the morning of Saturday, July 26. I was observing from a site on the Virgin River in Rockport, Utah, starting just before the beginning of twilight and ending about 5:30 AM MDT. The transparency was so-so (my green laser worked great!) but the seeing was very good to excellent. At that time Mars did not present a particularly interesting aspect to Earth, so perhaps I only noticed the following because there was little other detail to see: Along Mars' morning terminator, I saw a distinclty bluish hue. At first I attributed the color to my optics (5" Meade APO w/ Meade ultra-high transmission star diagonal, two 2x Barlows and a 4.7mm Plossl eyepiece, about 970x). To verify whether this was the case, I rotated the eyepiece, barlows and diagonal, removed one barlow and nudged the telescope, but the blue fringe was still there and was not observable elsewhere on the planet's limb. I've read about and seen the blue morning haze (frost?) in photographs, but I just assumed it was not observable visually. Anyone else had a similar experience? Kim A. Hyatt, AIA SL&A Architects 331 South Rio Grande, Suite 304 Salt Lake City, Utah 84101 Tel: 801.322.5550 x122 Fax: 801.322.5557

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RE: [Utah-astronomy] Green laser backlash
by Kim Hyatt 11 Aug '03

11 Aug '03

That night at Wolf Creek pass the air was nearly perfectly transparent. Even sighting along the barrel of the laser pointer, the beam was barely visible - not even bright enough to use as an aiming tool, at least for me. This weekend I had some fun with it in Yellowstone. We stayed up late to watch Grand Geyser. While returning to our car around 10:30, I played with the laser in the steam of a couple hot springs and small geysers. The "show" was kind of fun. My dogs also love to chase my red pointer. (I don't use the green ponter in the house.) Small minds, simple pleasures... -----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Monday, August 11, 2003 10:04 AM To: utah-astronomy(a)mailman.xmission.com Subject: RE: [Utah-astronomy] Green laser backlash --- Kim Hyatt <khyatt(a)smithlayton.com> wrote: > While I tried to > use the laser at Wolf > Creek, the air was so clear that the laser was > absolutely useless. Used as a pointer, this can be a problem (what a problem- perfect transparancy!), but I've noticed that even in very clear air, the beam can be seen if your line-of-sight is almost co-axial with it, so it still may work as a "finder" mounted on a telescope. I've used a red one this way (before abandoning it as a step backwards). For a real show, take out your laser this winter, during a snowstorm. They are also great fun annoying stray cats, who can't catch that dot no matter how hard they try! C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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RE: [Utah-astronomy] Green laser backlash
by Kim Hyatt 11 Aug '03

11 Aug '03

A couple thoughts: I recently purchased a green laser pointer, mainly for use at public star parties where I'd be surprised if anyone was attempting serious imaging. In the past, I've used a bright flashlight with a narrow beam, as I've noticed others using. While I tried to use the laser at Wolf Creek, the air was so clear that the laser was absolutely useless. I think we might consider an informal "policy" (or at least a request) to limit/ban the use of pointers of any kind at private star parties. For example, a bright flashlight was used by someone at a priviate star party where I was hoping to do some wide-angle photography. The flashlight and the observer's choice of sites to set up (between me and my south horizon) foiled my imaging attempts for that night. Since some laser manufacturers are promoting its use as a telescope aiming device, this genie may already be on the loose. Why not experiment with green lasers some evening at SPOC and see if the beam as most would use it really can affect imaging? We should consider wide-angle, long-exposure photography (such as I still do), CCD imaging, etc. How about it? -----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Monday, August 11, 2003 8:59 AM To: utah-astronomy(a)mailman.xmission.com Subject: RE: [Utah-astronomy] Green laser backlash Thanks Paul & Jim for your insights. Seems like this is just another variation on music at star parties. Some folks like it, some don't. The pointer would be appropriate for an outreach-type, public education star-party, scouting event, etc., but should probably be kept under wraps during dark-sky, "serious" (whatever that means) viewing or imaging sessions, club "dark of the moon" nights. In 1997, when I was going-out every clear night (and morning!) to shoot comet Hale-Bopp (images for the gallery coming SOON!), my biggest annoyance was airplanes. One-fourth of my frames were marred by jets passing-through the field; since my eye was glued to the narrow field of the guiding eyepiece for all of the 3-to-5 minuite exposures, I never noticed them until I had the rolls processed. Nothing can be done about jets, but if I had found several green laser "trails" on those exposures, there's a good chance I would have had a confrontation with the wielder. C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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