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mikeoday

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Image Comments posted by mikeoday

  1. Bright Nebula NGC 6188 and open cluster NGC 6193 in Ara

     

    Magnitude +5.19, RA 16h 41m 42s, Dec -48deg 48' 46"

    Approx. 3800 light years away

     

    Skywatcher Quattro 10" f4 Newtonian.

    Skywatcher AZ Eq6 GT Mount (on concrete pier)

    Orion 80mm f5 guide scope and auto guider - PHD2.

    Baader MPCC Mark 3 Coma Corrector, UHC-S 'nebula' filter.

    Nikon D5300 (unmodified).

    Field of view (deg) ~ 1.35 x 0.90.

    UHC-S - 32 x 180 sec ISO800 (14bit NEF, Long Exp. NR on).

    Pixinsight and photoshop

    7 July 15 (processed 29 August 15)

  2. Thanks Scott.  Astrophotography is an extremely frustrating hobby, what with clouds, wind, street lights, the moon and of course more clouds; but its all worth it when one manages to produce an image of one of these very dim and far off wonders.

    Cheers

    Mike

  3. Thank you Gail.

    I had a small telescope when I was a little boy and at that time I dreamed of having a 'great big telescope', maybe 5 or even 6 inches.  Telescope technology, like almost everything else, has come along in leaps and bounds and of course, with China now making so many different telescopes the price has come right down.  The one I have now has a 10" diameter mirror and costs only a little more (in real terms) than the little one I had so long ago.  

    All the best

    Mike

  4. Hi Gail

     

    I purchased a telescope last Easter (the first one I've owned since I was boy).  It's a Newtonian Reflector with a 10" diameter mirror with a focal length of 1000mm.  It is fitted to a motorised and computer controlled equatorial telescope mount that ensures that the scope keeps pointing at the target as the earth rotates.  I don't look through it at all; I just mount a small light weight DSLR where one would normally place an eyepiece.  

     

    Because these objects are so dark it is necessary to take long exposures as the mount rotates to track the target.  In this case I took a large number of 5 min exposures at ISO200.  I use software to align and integrate (stack) the separate images to produce a single photo.  The advantage of stacking is that the noise, which is randomly scattered across the image, is averaged out while the real signal is summed.  This greatly increases the signal to noise ratio and brings out the detail that would otherwise be overwhelmed by the noise in a single image.

     

    I built myself an outdoor observatory so I can fix the telescope to a pier and leave it outside during long weekend sessions and then bring it in when I won't be using if for a while.  The link shows photos of the scope and observatory.

     

    http://stargazerslounge.com/topic/234625-mikes-roll-away-shed-observatory/

     

    Cheers

    Mike

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