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Telescope battery widget (much ado aboot nothing)

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  • Telescope battery widget (much ado aboot nothing)

    David C's post on the Linux astronomy viewer started a snowball for me. I've had an 8" scope for a number of years but it's been in storage for a long time. I dug it out and have been getting re-inspired.

    on to the on-topic:
    It has an illuminated reticle finder that I've never had the pleasure of seeing powered up since the mercury battery has been obsolete since before I got it. The alkaline replacement is too pricey for my cheap ba$tardiness so I machined a little plastic battery widget so I can power it with a wall wart or small AA battery pack. It works! I got to see the the reticle lit up last night for the first time ever.




    YOD, did you have any success seeing stuff through your scope?

  • #2
    Vinto,

    I highly recommend using a zero power finder on your scope. I have a Telrad on mine and it is really nice to use. It projects a virtual reticle image on the sky and requires no squinting. You use both eyes, one looking through the finder and the other at the sky. You see the reticle as if it were painted on the sky. It makes no difference if you wear glasses and everything is right side up and not mirrored.

    Nothing beats a Telrad for ease of use.

    http://www.adorama.com/ATTFS.html
    Free software for calculating bolt circles and similar: Click Here

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    • #3
      Thanks for the suggestion Evan.
      I actually owned one of those years ago. I never attached it to the scope - it was still in the box and I sold it to a buddy who has used it a lot. I never even had the chance to see it on his scope either.

      There is a really active astronomical society in Kansas City and I plan to start going to their gatherings. First one is next weekend. I figger if I can check some of their equipment out firsthand it would have to help a lot in determining what I think I could use.

      The last time I had my scope out I didn't have much of a shop (been a LONG time). I always thought it would be fun to make my own GEM or something. Since I have the machinery now I might consider it again. My project list is on a long spool of paper so I think there's room to add it to the list.

      I never even successfully polar aligned my scope and had the setting circles set correctly until one evening earlier this week, which I'm embarrased to admit. It's amazing how far computerized mounts have come since I last looked into it. It's hard to believe that they can automatically adjust for periodic error, automatically correct tracking, automatically focus, automatically etc. Even though I'm a novice at best, I still think I'm old school though. I think I can be pretty happy with just a clock drive and setting circles.

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      • #4
        Here is a handy celestial pole finder I whipped up for polar alignment. Download by clicking on the image and print it out. Put the two discs together. Works well for determining the true celestial pole. It is only for the northern hemisphere.

        http://vts.bc.ca/astrophoto/finder.htm
        Free software for calculating bolt circles and similar: Click Here

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        • #5
          Venito, negative. I set it up in the back yard on a bright day and had a hard time seeing farms on the other hillside from mine. It's a really cheap thing that someone at work gave me when Imentioned I had an interest. I'd like to one day get a nice scope but I'm in no hurry to do it. When I retire I want to whiz away the evenings in the back yard surrounded by stars, corn and mosquitos If you got an 8" inch it sounds like you're having some fun!

          [This message has been edited by Your Old Dog (edited 01-21-2006).]
          - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
          Thank you to our families of soldiers, many of whom have given so much more then the rest of us for the Freedom we enjoy.

          It is true, there is nothing free about freedom, don't be so quick to give it away.

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          • #6
            So called "department store" telescopes aren't worth a pinch of snot. They are a total waste of money. The sad thing is that a lot of people buy them and expect to see stuff that looks like pictures from the Hubble. A decent telescope starts at around $400 or so.
            Free software for calculating bolt circles and similar: Click Here

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            • #7
              cool pole finder Evan. I'll put one together and try it out.

              I agree that cheapie telescopes are not worth much. It's hard to hold any interest when you run into many obstacles. However and FWIW, I've had a couple of those before and what I noticed is that the weakest link is the eyepieces. It's like trying to see through an aquarium. If a guy had a cheapie scope I'd recommend he first make sure it's collimated, then try a good borrowed 1-1/4" eyepiece on it (may have to modify/adapt the scope to take the larger eyepiece). If you can't borrow one, they are a good investment if you think you will get into a good scope later since eyepieces fit into most any scope.

              If it doesn't work, then you know. If it does work, then it's a pleasant surprise. It still doesn't hold a candle to a good quality scope, but it can still provide a measure of edu-tainment.

              $.02

              p.s. YOD. What type of scope is it that you have? (refractor, Newtonian reflector, catadioptric of some kind?) Maybe there's some twiddling can be done to make it peform a little better.

              [This message has been edited by vinito (edited 01-22-2006).]

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              • #8
                As long as astronomy came up, here's my 2 cents.

                I recently got a Canon Digital Rebel XT camera mainly to take pictures of the sky. In particular, I'm trying to record the eclipses (occultations) of the binary system U Cephei. It lies only a few degrees from the pole, so with a 50 mm lens I can get 12 hours of photos without a clock drive.(8 second exposures every four minutes give stars to about magnitude 11 without trailing)

                To make life pleasant, I built an insert to replace the screen in the casement window in my 2nd floor computer room that faces due north. The insert is framed with aluminum channel and holds window glass in the lower 3 feet. The top 6" have a frame that I can bolt a camera holder to. When I have a clear night, I mount the camera aimed out the window and set the altitude to 44 degrees. A USB cable allows the computer to control the camera, and an adapter from Canon eliminates battery worries.

                I'm using Iris software to extract light curves from the images. I hesitate to go on and on in this forum, but will be happy to add detail.


                Many thanks to Evan for the pole finder!

                ------------------

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                • #9
                  The Canon Digital Rebel is perfect for astrophotography. I put this up here last year but it bears repeating. This photo would be impossible with film. It is a 30 second exposure at ISO 1600. During the exposure I waved about a tiny single white LED flashlight to illuminate the trees.



                  [This message has been edited by Evan (edited 01-23-2006).]
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                  • #10
                    Evan that is a remarkable shot. very nice. why though couldn't you have done the same with film?
                    .

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                    • #11
                      "why though couldn't you have done the same with film?"

                      Several reasons. I do have some Fuji Superia 1600 film. However, film suffers from an effect called reciprocity failure. As the silver halide crystals collect photons less crystals remain to be converted. Over the course of an exposure the effective film speed steadily falls, eventually to nearly zero. A digital imager doesn't do this. It has the same quantum efficiency until it becomes saturated.

                      This was only a 30 second exposure but in this circumstance reciprocity failure would already start to become noticiable with film. In particular with film in order to collect the light from the distant trees would have required at least a one minute exposure or longer. That would have been long enough for significant trailing of the stars to be visible. 30 seconds was the most I could get away with and not have too much trailing.

                      This was taken on a tripod with no tracking drive. I could use a tracking mount to prevent star trails but then the trees would be blurred.

                      BTW, feel free to use the image if you wish. I don't post anything on the web that I don't want people to use.

                      [This message has been edited by Evan (edited 01-23-2006).]
                      Free software for calculating bolt circles and similar: Click Here

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                      • #12
                        That's a great picture Evan.
                        - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                        Thank you to our families of soldiers, many of whom have given so much more then the rest of us for the Freedom we enjoy.

                        It is true, there is nothing free about freedom, don't be so quick to give it away.

                        Comment


                        • #13
                          My specialty in astrophotography is capturing unusual scenes. Here is an extremely rare photo that I took during the great Leonid meteor storm of 2001. It is a meteor that takes a non-straight path. This image was featured on Discovery Channel's Daily Planet show a few years ago. This is rarely seen and this may be the only photo in existence of such a meteor according to a professional astronomer on the show. You can also see a straight trail just above the horizon to the right of the house. The sky glow is from the town.



                          Here is a pic of noctilucent clouds. They are only seen in a narrow band of latitudes in the range of 50 to 60 degrees north usually. They are clouds that form around 82 kilometers high far above the normal weather. They are illuminated from below by the sun well after full dark.



                          Even more rare is this pic of a triple conjuction of Jupiter, Venus and Mars seen through noctilucent clouds.



                          Here is a shot of Mercury (tiny spot down by the top of the tree) and the Moon in the same picture.



                          This is a shot of the moon at midnight:



                          Free software for calculating bolt circles and similar: Click Here

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