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An OFLI Chronicle: “Out There” Dark Sky Trips in 2014 and 2015

May 27 2016 12:48 PM | jrbarnett in Articles

In addition to more or less regular, weather permitting, observing sessions at Dan Parker’s Sonoma farm, and occasional public outreach, the club undertakes one or two dark sky camping trips a year.  In addition to dark skies and astronomy, these quests also feature daytime activities well outside the day-to-day for most of us. 

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CAPTURING COSMIC RAYS WITH A DIGITAL CAMERA

Mar 21 2016 08:25 AM | rekokich in Articles

Muons can be detected with cloud chambers, Geiger counters, and scintillator detectors, but can also be recorded with common digital camera CCD and CMOS chips which are sensitive to charged particles. Muon flux at the surface of the Earth averages approximately 1 particle per square centimeter per minute. The surface area of the APS-C camera sensor (22.3 x 14.9 mm) is 3.3 cm2, which means that we can expect on average 3 muon strikes on the sensor during a 1 minute exposure.

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Carl Zeiss 300MM F5.6 S-Tessar RFT

Mar 10 2016 08:39 AM | Tom Duncan in Articles

I recently got a Carl Zeiss S-Tessar 300mm f5.6 barrel lens (no aperture nor shutter) that came out of an old copy machine or color comparator, not sure which. While only demanding $50-$100 on the used photographic market it was suggested it might make a good rich field telescope. So I made one.

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A Visit to the Museum of Astronomical Telescopes In Tawa, Japan

Feb 16 2016 10:10 AM | davidmcgo in Articles

Overall, my experience at the Museum was incredible and it was nearly sensory overload to see so many vintage telescopes that I have only read about and all in one place. The zeal, skill, and dedication of these fellow amateur astronomers is creating something unique in the entire world, a hands on experience dedicated to preserving the entire legacy and heritage of telescopes and astronomy in Japan, without which many of us would never have received that first telescope under the Christmas tree in our youth.

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A Novel Alt-Az Mount for a Rich Field Telescope

Feb 08 2016 03:49 PM | mrtoad in Articles

Most of us have had the desire to take a break from using the average telescope with its relatively high power and concomitant narrow field of view and difficulty in finding targets. The so- called rich field telescope or large binoculars seem to fill the bill with their low power and wide fields. The question then becomes how to mount the thing for comfortable, extended viewing.

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Toasty Dew Heaters

Feb 07 2016 12:48 PM | bmwscopeguy in Articles

Wait – don’t throw out that old toaster! Lurking within every toaster is about 20 feet of potential dew strip in the form of the elements it uses for burning your bagels.

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Night Vision Astronomy 2015: Three Perspectives

Jan 06 2016 05:15 PM | The Ardent in Articles

Night Vision technology is a powerful tool to enhance observing. Like any observing method, it had its advantages and drawbacks. Three Cloudy Nights members offer their experience.

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There's a Catch!

Nov 25 2015 12:26 PM | GeezerGazer in Articles

For at least 10 years, observers have complained in forums about eyepiece barrel undercuts causing various problems, but especially catches. Because of my own experiences with catches occurring during insertion or extraction of an eyepiece when used with an adapter, I decided to do some investigation as to why. Catches, I found, are not a one sided issue.

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Blue Skies, Red Sunsets & Company: Part 5 - Green Flashes

Nov 24 2015 11:08 AM | Snickersnee in Articles

If you watch enough sunsets, you'll eventually see one where, just as the last sliver of sun slips away, it turns green or reappears for an instant as a flash of greenish light. Congratulate yourself - you have just seen the famous green flash!

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Notes on the Construction of an Oiled Contact Doublet

Nov 17 2015 04:09 PM | mrtoad in Articles

This is a description of my adventures with the fabrication of a 6” f/15 oiled achromat.It is assumed you will know all about grinding, polishing and figuring. It will discuss some problems I ran into and what I did to solve them in the easiest and most practical way, as well as things to watch out for. This is not a step by step description of the making of a refracting objective let alone the complete telescope.



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