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Any amateur astronomers?

  1. #16
    Join Date
    Mar 2017
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    Orange County, California
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    265

    Wintermint -- If you were there in 1965, maybe you saw me. I was the guy in a sailor suit with a camera hanging from my neck. I've been to the top of Victoria peak. Here are two of my buddies with a view of Victoria basin on a hazy day. The USS Diodon is a tiny spec between their knees.

    40.jpg

    Don

  2. #17
    Join Date
    May 2017
    Location
    Southern California's High Mojave Desert
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    910
    Hey Grampa Don,

    Before retiring and moving to the High Desert, I also lived close to Disneyland, in a private condo complex on Katella Ave.

    Did you ever participate in a Star Party? While living in OC, I belonged to the Orange County Astronomers, which at the time had about 1200 members.

    Their observing site was in the wilderness area near Anza.

    Cheers,

    HiDesertHal (This was a Scope I had a few years ago...it was a 17.5" Discovery rigid-tube Dobsonian, and weighed 198 pounds. Not my biggest, however.)
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    Last edited by HiDesertHal; 06-01-2017 at 07:15 AM.

  3. #18
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    Mar 2017
    Location
    Orange County, California
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    265
    Hi Hal,

    I know about the Orange County Astronomers. They are very active. But, I don't drive at night anymore, so I do my observing from my driveway.

    Don

  4. #19
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    May 2017
    Location
    Southern California's High Mojave Desert
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    910
    Here's the biggest Telescope I ever owned, a 20-inch Truss-Tube Dobsonian. It was custom-built for me by Obssession Telescopes.

    A ladder was needed to access the eyepiece.

    An absolute joy on remote deep-sky objects!

    HiDesertHal
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  5. #20
    Join Date
    May 2015
    Posts
    19
    I am a photographer by hobby who is interested in the night sky only when some unique event occurs. Waiting for the total eclipse to occur August 21. In the mean time, I take photos of the full moons with a 400mm lens when the sky is clear in Houston. I also took a picture of the milky way when I was in Iceland.
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  6. #21
    Join Date
    Jan 2017
    Location
    Northwestern Ontario Canada
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    3,187
    Total eclipse in August?

  7. #22
    Join Date
    May 2017
    Location
    Southern California's High Mojave Desert
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    910
    My advice for those who want to observe the moon visually:

    DON'T EVER observe the Full Moon through a telescope! It's like looking directly into a Searchlight!

    The glare and the after image will ruin your eyesight for hours afterward, spoiling images of faint, deep-sky obgects which are more interesting anyway.

    Remember...you're looking at reflected SUNLIGHT!

    If you MUST observe the moon, wait for a Crescent or Quartering phase; this way you'll see more surface detail in the Craters, Rills, and Maria.

    A Full Moon does not present the grazing illumination angle from the Sun that brings out detail...it's just too flat and glaring.

    Take a slice of coarse bread and a flashlight into a dark closet. Shine the flashlight directy on the face of the bread.

    Then shine the flashlight on the bread fom the side, using a grazing illumination. Note the difference in detail!

    HDH
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  8. #23
    Join Date
    Mar 2017
    Location
    Orange County, California
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    265
    Quote Originally Posted by HiDesertHal View Post
    My advice for those who want to observe the moon visually:

    DON'T EVER observe the Full Moon through a telescope! It's like looking directly into a Searchlight!

    The glare and the after image will ruin your eyesight for hours afterward, spoiling images of faint, deep-sky obgects which are more interesting anyway.

    HDH
    I think you should qualify that. Sure, if you have a 20 inch mirror it's going to be blinding. But, I often look at the full moon with my 8 inch and it's not a big deal. And most beginners are going to have something much smaller. And, you aren't likely to be doing much deep sky observing anyway on a full moon night. It's true, you can't see many details in a full moon, but it is still very pretty. Ray patterns like Tycho really stand out.

    Don

  9. #24
    Join Date
    Jun 2014
    Location
    upstate NY
    Posts
    1,833
    Well, some guys drive BIG cars....

    telescope.JPG
    When you do things right, people won't be sure you've done anything at all.

  10. #25
    Join Date
    Jun 2014
    Location
    upstate NY
    Posts
    1,833
    I was really into astronomy when I was a kid. I even had posters on my bedroom wall of the Rand McNally solar system (see photo) and moon. This was back when Jupiter had 12 moons and Saturn had 9 and Pluto was a planet. Then I found out "real" astronomers don't just look through telescopes and they need to know a lot of complicated math (when I am not good at - even simple math). There went THAT career....

    solar system poster.jpg
    When you do things right, people won't be sure you've done anything at all.

  11. #26
    Join Date
    Mar 2017
    Location
    Orange County, California
    Posts
    265
    Professional astronomers collect and study data. The big observatories are pretty much automated. Amateurs look at the sky for pure enjoyment.

    Don

  12. #27
    Join Date
    May 2017
    Location
    Southern California's High Mojave Desert
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    910
    Hey Grampa Don,

    Sure, I'll qualify my previous statements!

    The human eye, when fully dark-adapted, has an average diameter of 5 mm. Even a small 8" telescope has a mirror diameter of 203.2mm, so the diameter ratio between eye and mirror is 203.2mm / 5mm =40.64.

    BUT...this is the ratio of the diameters. The ratio of the areas is 1651.6, (disregarding the blockage of the Secondary mirror), and this is how much brighter the image in an 8" scope will be compared to the naked eye.

    The apertures of my large scopes ranged from 12.5" to 20", so this would produce an extreme retina-damaging glare unless a moon filter were used under full-moon conditions.

    A 10" mirror would reflect 1.56 times as much light as an 8" mirror, or 2576.5 times the naked eye.
    A 12" mirror would reflect 2-1/4 times as much light as an 8" mirror, or 3716.1 times the naked eye.
    A 16" mirror would reflect 4 times as much light as an 8" mirror, or 6606.4 times the naked eye.
    A 20" mirror would reflect 6-1/4 times as much light as an 8" mirror, or 10,322.5 times the naked eye.

    This is why I cautioned against observing the full moon through a telescope, but I should have said a large telescope...my error!

    Shown: 6" Computerized Locating and Tracking Refractor.

    HiDesertHal
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