RE: [Utah-astronomy] Observing notes - Ealing 4-26-2007 Lunar visual
Don, Thank you for showing me a 2.5mm and 4m TMB Burgress planetary eyepieces on Saturn using Seigfried's new refractor at 400x-500x at Friday's Harmon's urban star party. A high-end engineered wide-angle 60deg short (3 and 5mm) eyepieces made good sense for planetary work. The wide-angle image spreads a dimmer image of the small planetary apparent disk over a relatively larger area of the fovea, resulting in a better perception of details. Spreading the planetary disk with a wide angle also probably breaks down the assumptions behind Knisely's useful magnfication rules-of-thumb that I normally apply to resolution limits. I'm not sure if we pushed Seigfreid's refractor into the range of extreme magnification on Saturn, but the review literature for the TMB mentions that unlike stock DSO lenses, it is engineered to reduce lateral scattering that causes multiple images of a feature to appear when used on very bright targets, e.g. - lunar visual observing. Those secondary scattered images are present in Plossels, but are two dim to perceived. Undoubtedly, your call that that in part was the distortion that I was seeing on the Ealing is right. Performance and price usually, or at least should be, related. At $100 a pop, the TMBs seem like a good price point compromise as compared to a TeleVue 2.5 or 5 Nagler at $290 a lens. You mentioned you were looking at the Plato craterlets as a resolution test. Here's Knisely's map for a Plato crater diameter sequence diagram: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/520616/page... Cloudy Nights, Lunar Forum, 7/18/2005 "Guide to Plato Craterlets" D. Knisely (map and list) - Kurt Astromart TMB eyepiece review http://www.astromart.com/articles/article.asp?article_id=464 Knisely's Useful Magnifications Modified to add a 5mm exit pupil for "low-medium power" LOW POWER (3.7 to 9.9x per inch of aperture)(6.9mm to 2.6mm exit pupil) LOW-MEDIUM POWER (5.1 to 9.9x per inch of aperture)(5mm to 2.6mm exit pupil) MEDIUM POWER (10x to 17.9x per inch of aperture)(2.5mm to 1.4mm exit pupil) HIGH POWER (18x to 29.9x per inch of aperture)(1.4mm to 0.8mm exit pupil) VERY HIGH POWER (30x to 41.9x per inch of aperture)(0.8mm to 0.6mm exit pupil) EXTREME POWER (42x to 75x per inch)(0.6mm to 0.3mm exit pupil) EMPTY MAGNIFICATION (100x per inch and above) Modified from D. Knisely, 5/14/2004 sci.astro.amateur Usenet post, Thread "Eyepiece advice, again" _______________________________________________ Sent via CSolutions - http://www.csolutions.net
Looks like we should use them all at spoc tonite and see Bob Bob Moore Commerce CRG - Salt Lake City office 175 East 400 South, Suite 700 Salt Lake City, Utah 84111 Direct: 801-303-5418 Main: 801-322-2000 Fax: 801-322-2040 BMoore@commercecrg.com www.commercecrg.com -----Original Message----- From: utah-astronomy-bounces+bmoore=commercecrg.com@mailman.xmission.com [mailto:utah-astronomy-bounces+bmoore=commercecrg.com@mailman.xmission.c om] On Behalf Of Kurt Fisher Sent: Saturday, April 28, 2007 3:06 PM To: utah-astronomy@mailman.xmission.com Subject: RE: [Utah-astronomy] Observing notes - Ealing 4-26-2007 Lunar visual Don, Thank you for showing me a 2.5mm and 4m TMB Burgress planetary eyepieces on Saturn using Seigfried's new refractor at 400x-500x at Friday's Harmon's urban star party. A high-end engineered wide-angle 60deg short (3 and 5mm) eyepieces made good sense for planetary work. The wide-angle image spreads a dimmer image of the small planetary apparent disk over a relatively larger area of the fovea, resulting in a better perception of details. Spreading the planetary disk with a wide angle also probably breaks down the assumptions behind Knisely's useful magnfication rules-of-thumb that I normally apply to resolution limits. I'm not sure if we pushed Seigfreid's refractor into the range of extreme magnification on Saturn, but the review literature for the TMB mentions that unlike stock DSO lenses, it is engineered to reduce lateral scattering that causes multiple images of a feature to appear when used on very bright targets, e.g. - lunar visual observing. Those secondary scattered images are present in Plossels, but are two dim to perceived. Undoubtedly, your call that that in part was the distortion that I was seeing on the Ealing is right. Performance and price usually, or at least should be, related. At $100 a pop, the TMBs seem like a good price point compromise as compared to a TeleVue 2.5 or 5 Nagler at $290 a lens. You mentioned you were looking at the Plato craterlets as a resolution test. Here's Knisely's map for a Plato crater diameter sequence diagram: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/520616/ page/0/view/collapsed/sb/5/o/all/fpart/1 Cloudy Nights, Lunar Forum, 7/18/2005 "Guide to Plato Craterlets" D. Knisely (map and list) - Kurt Astromart TMB eyepiece review http://www.astromart.com/articles/article.asp?article_id=464 Knisely's Useful Magnifications Modified to add a 5mm exit pupil for "low-medium power" LOW POWER (3.7 to 9.9x per inch of aperture)(6.9mm to 2.6mm exit pupil) LOW-MEDIUM POWER (5.1 to 9.9x per inch of aperture)(5mm to 2.6mm exit pupil) MEDIUM POWER (10x to 17.9x per inch of aperture)(2.5mm to 1.4mm exit pupil) HIGH POWER (18x to 29.9x per inch of aperture)(1.4mm to 0.8mm exit pupil) VERY HIGH POWER (30x to 41.9x per inch of aperture)(0.8mm to 0.6mm exit pupil) EXTREME POWER (42x to 75x per inch)(0.6mm to 0.3mm exit pupil) EMPTY MAGNIFICATION (100x per inch and above) Modified from D. Knisely, 5/14/2004 sci.astro.amateur Usenet post, Thread "Eyepiece advice, again" _______________________________________________ Sent via CSolutions - http://www.csolutions.net _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com
Kurt, Thanks for the link to the Plato image. It is a good question how high the TEC 160 can go without getting empty magnification. We need to test it on a very good night with Siegfried's new 900 mount. The Byers he had it on at Harmons doesn't have slow motion and with powers over 350x it was hard to achieve focus because of vibration in the mount when you touched it while trying to focus. Don -----Original Message----- From: utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com [mailto:utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com] On Behalf Of Kurt Fisher Sent: Saturday, April 28, 2007 3:06 PM To: utah-astronomy@mailman.xmission.com Subject: RE: [Utah-astronomy] Observing notes - Ealing 4-26-2007 Lunar visual Don, Thank you for showing me a 2.5mm and 4m TMB Burgress planetary eyepieces on Saturn using Seigfried's new refractor at 400x-500x at Friday's Harmon's urban star party. A high-end engineered wide-angle 60deg short (3 and 5mm) eyepieces made good sense for planetary work. The wide-angle image spreads a dimmer image of the small planetary apparent disk over a relatively larger area of the fovea, resulting in a better perception of details. Spreading the planetary disk with a wide angle also probably breaks down the assumptions behind Knisely's useful magnfication rules-of-thumb that I normally apply to resolution limits. I'm not sure if we pushed Seigfreid's refractor into the range of extreme magnification on Saturn, but the review literature for the TMB mentions that unlike stock DSO lenses, it is engineered to reduce lateral scattering that causes multiple images of a feature to appear when used on very bright targets, e.g. - lunar visual observing. Those secondary scattered images are present in Plossels, but are two dim to perceived. Undoubtedly, your call that that in part was the distortion that I was seeing on the Ealing is right. Performance and price usually, or at least should be, related. At $100 a pop, the TMBs seem like a good price point compromise as compared to a TeleVue 2.5 or 5 Nagler at $290 a lens. You mentioned you were looking at the Plato craterlets as a resolution test. Here's Knisely's map for a Plato crater diameter sequence diagram: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/520616/ page/0/view/collapsed/sb/5/o/all/fpart/1 Cloudy Nights, Lunar Forum, 7/18/2005 "Guide to Plato Craterlets" D. Knisely (map and list) - Kurt Astromart TMB eyepiece review http://www.astromart.com/articles/article.asp?article_id=464 Knisely's Useful Magnifications Modified to add a 5mm exit pupil for "low-medium power" LOW POWER (3.7 to 9.9x per inch of aperture)(6.9mm to 2.6mm exit pupil) LOW-MEDIUM POWER (5.1 to 9.9x per inch of aperture)(5mm to 2.6mm exit pupil) MEDIUM POWER (10x to 17.9x per inch of aperture)(2.5mm to 1.4mm exit pupil) HIGH POWER (18x to 29.9x per inch of aperture)(1.4mm to 0.8mm exit pupil) VERY HIGH POWER (30x to 41.9x per inch of aperture)(0.8mm to 0.6mm exit pupil) EXTREME POWER (42x to 75x per inch)(0.6mm to 0.3mm exit pupil) EMPTY MAGNIFICATION (100x per inch and above) Modified from D. Knisely, 5/14/2004 sci.astro.amateur Usenet post, Thread "Eyepiece advice, again" _______________________________________________ Sent via CSolutions - http://www.csolutions.net _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com
I have a 5mm nagler so you don't need to buy one for a comparison test. We can use it to test Siegfried's scope. Bob Moore Commerce CRG - Salt Lake City office 175 East 400 South, Suite 700 Salt Lake City, Utah 84111 Direct: 801-303-5418 Main: 801-322-2000 Fax: 801-322-2040 BMoore@commercecrg.com www.commercecrg.com -----Original Message----- From: utah-astronomy-bounces+bmoore=commercecrg.com@mailman.xmission.com [mailto:utah-astronomy-bounces+bmoore=commercecrg.com@mailman.xmission.c om] On Behalf Of Don J. Colton Sent: Monday, April 30, 2007 10:59 AM To: 'Utah Astronomy' Subject: RE: [Utah-astronomy] Observing notes - Ealing 4-26-2007 Lunar visual Kurt, Thanks for the link to the Plato image. It is a good question how high the TEC 160 can go without getting empty magnification. We need to test it on a very good night with Siegfried's new 900 mount. The Byers he had it on at Harmons doesn't have slow motion and with powers over 350x it was hard to achieve focus because of vibration in the mount when you touched it while trying to focus. Don -----Original Message----- From: utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com [mailto:utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com] On Behalf Of Kurt Fisher Sent: Saturday, April 28, 2007 3:06 PM To: utah-astronomy@mailman.xmission.com Subject: RE: [Utah-astronomy] Observing notes - Ealing 4-26-2007 Lunar visual Don, Thank you for showing me a 2.5mm and 4m TMB Burgress planetary eyepieces on Saturn using Seigfried's new refractor at 400x-500x at Friday's Harmon's urban star party. A high-end engineered wide-angle 60deg short (3 and 5mm) eyepieces made good sense for planetary work. The wide-angle image spreads a dimmer image of the small planetary apparent disk over a relatively larger area of the fovea, resulting in a better perception of details. Spreading the planetary disk with a wide angle also probably breaks down the assumptions behind Knisely's useful magnfication rules-of-thumb that I normally apply to resolution limits. I'm not sure if we pushed Seigfreid's refractor into the range of extreme magnification on Saturn, but the review literature for the TMB mentions that unlike stock DSO lenses, it is engineered to reduce lateral scattering that causes multiple images of a feature to appear when used on very bright targets, e.g. - lunar visual observing. Those secondary scattered images are present in Plossels, but are two dim to perceived. Undoubtedly, your call that that in part was the distortion that I was seeing on the Ealing is right. Performance and price usually, or at least should be, related. At $100 a pop, the TMBs seem like a good price point compromise as compared to a TeleVue 2.5 or 5 Nagler at $290 a lens. You mentioned you were looking at the Plato craterlets as a resolution test. Here's Knisely's map for a Plato crater diameter sequence diagram: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/520616/ page/0/view/collapsed/sb/5/o/all/fpart/1 Cloudy Nights, Lunar Forum, 7/18/2005 "Guide to Plato Craterlets" D. Knisely (map and list) - Kurt Astromart TMB eyepiece review http://www.astromart.com/articles/article.asp?article_id=464 Knisely's Useful Magnifications Modified to add a 5mm exit pupil for "low-medium power" LOW POWER (3.7 to 9.9x per inch of aperture)(6.9mm to 2.6mm exit pupil) LOW-MEDIUM POWER (5.1 to 9.9x per inch of aperture)(5mm to 2.6mm exit pupil) MEDIUM POWER (10x to 17.9x per inch of aperture)(2.5mm to 1.4mm exit pupil) HIGH POWER (18x to 29.9x per inch of aperture)(1.4mm to 0.8mm exit pupil) VERY HIGH POWER (30x to 41.9x per inch of aperture)(0.8mm to 0.6mm exit pupil) EXTREME POWER (42x to 75x per inch)(0.6mm to 0.3mm exit pupil) EMPTY MAGNIFICATION (100x per inch and above) Modified from D. Knisely, 5/14/2004 sci.astro.amateur Usenet post, Thread "Eyepiece advice, again" _______________________________________________ Sent via CSolutions - http://www.csolutions.net _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com
Patrick, are you around? I tried to send you a message at your email and it didn't go through. I'm wondering if I have an outdated address. Could you let me know? Thanks, Joe
participants (4)
-
Bob Moore -
Don J. Colton -
Joe Bauman -
Kurt Fisher