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Posts Made By: Alan French

July 1, 2011 02:23 PM Forum: LUNATICS

Tyco LROC image

Posted By Alan French
Cool. Your URL didn't work for me - it included the ".)" at the end.

This should...
http://wms.lroc.asu.edu/lroc_browse

Clear skies, Alan

July 3, 2011 04:31 PM Forum: After Dark

Milky way video AWESUM

Posted By Alan French
Lovely! Thanks.

Clear skies, Alan

August 8, 2011 06:51 PM Forum: My Favorite WIMP.COM or YOUTUBE.COM

Eagle Owl at 1000 fps

Posted By Alan French
Very nice! Thanks for sharing.

Clear skies, Alan

August 30, 2011 03:00 AM Forum: Equipment Talk

Mask for 8" refractor

Posted By Alan French
There is really no need for a mask, which reduces resolution or filters. While the Moon may seem overly bright, it is not really all that bright and time and experience will allow your eyes to adjust.

I've tried both neutral density and polarizing filters on the Moon (with an 8" refractor). The Moon has some lovely bright, white areas, and very black shadows. Filters muddy the pure whites and turn the blacks somewhat gray.

An interesting read is "Some thoughts on the art of vision" on page xx of Harold Hill's "A Portfolio of Lunar Drawings."

Mr. Hill makes no mention of using filters, and the fine drawings of the Moon done by Alika Herring and published in Sky & Telescope from time to time long ago (in the 1950s and 60s, IIRC) make no mention of filters.

Clear skies, Alan

September 2, 2011 09:53 PM Forum: Eyepieces

ES 120 degree fov eyepiece coming out

Posted By Alan French
Too rich for my blood, and a larger AFOV than I feel I need. I'm not a fan of "looking around," I like to be able to take in the entire field at once.

Clear skies, Alan

September 3, 2011 12:11 AM Forum: Global Warming - REAL or NOT

No gulf hurricanes again this year

Posted By Alan French
I think the link of extreme weather to global warming is little more than speculation.

It may not be a hurricane, but I don't think folks need this...
"Slow-moving Tropical Storm Lee could dump up to 20 inches of rain on parts of the Gulf Coast, according to the National Hurricane Center."

Less rain from Irene did some major damage in the Northeast.

Clear skies, Alan

September 16, 2011 05:29 PM Forum: Equipment Talk

building a refractor

Posted By Alan French
There's also Hastings...

http://hastingsirrigation.com/node/19

Clear skies, Alan

November 9, 2011 06:47 PM Forum: Solar System Observing

Solar Filter for Canon IS 15x50 binoculars

Posted By Alan French
White light filters are easy to make using Baader AstroSolar Safety film, which is available from Astro-Physics.

I have a pair for my 12x36 Canon IS, and they provide very nice views of sunspots. I am in the process of making them for my wife's 18x50s. To start, I am just building up a ring of layers of thin cardboard for each objective. I started by wrapping one layer around each protruding cell and gluing the overlap, and have continued adding layers, holding them in place with a rubber band. Since the objective spacing doesn't change on the Canons, I'll likely just glue the two rings to flat piece of stiff cardboard that has circular holes matching the objectives, and then add a piece of Baader material with double sided tape.

I'll post some photos when I get a chance.

I'm also making filters for my birding scope and our little 4.25" Starblast.

Clear skies, Alan


November 27, 2011 09:00 PM Forum: Astro-Physics

Eye Pc

Posted By Alan French
A quick search of AM classifieds for the past year shows AP SPLs selling for $350 to $450, with quite a few just under $400.

Clear skies, Alan

December 3, 2011 12:31 AM Forum: Deep Sky Observing

Anybody ever make an occulting bar for an EP?

Posted By Alan French
I just use a thin strip of aluminum foil attached to the field stop with rubber cement. It works just fine. (Just remember to remove it once you're done with. I got a surprise one night with my binoviewer in a refractor.)

Clear skies, Alan

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