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Recent pics

  1. Dec 7, 2015 #1

    Andy Resnick

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    Back up and running; got these last weekend.

    Composite_s_zpslw1d8b7a.jpg

    400/2.8, 50 minutes total integration time, 10s ISO 2000 individual frames.

    orion_14m_2s_zpspqfr5uzx.jpg

    800/5.6, 14 minutes total, 6s ISO 2000 individual frames.

    It's been an adjustment to the new sensor, my alignment technique had to improve by about 2x to eliminate residual drift; also the sony had in-camera stabilization which gave me another stop's worth of shutter time.
     
  2. jcsd
  3. Dec 7, 2015 #2
    Nice stuff.
    Is the top one Ursa Major?
    The second one is what?
     
  4. Dec 8, 2015 #3

    davenn

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    no, that's M45, The Pleiades star cluster

    That's M42, the Orion Nebula ... it shouldn't really be that blue, that nebula has lots of red in it

    Maybe Andy can let us know how he was doing the processing ?


    Dave
     
  5. Dec 8, 2015 #4

    Andy Resnick

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    I struggle with colorimetrics- the sky is tinted red from light pollution, so I try and fix it by post-processing and normalizing the colors such that the sky is a neutral dark grey and bright stars are white, then bumping up the color saturation. I never get the same colors twice.... those images do look 'bluer' than I recall setting them, tho.
     
  6. Dec 8, 2015 #5

    Andy Resnick

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    See, it's pretty easy to alter the colors:

    orion_14m_2.tif%20RGB_zps6hcuglwx.jpg

    orion_14m_2.tif%20RGB-1_zpsfqvkiy4y.jpg

    To be fair, I've been staying up late for the stars and getting up early for the moon:

    DSC_2041s_zpsqnt3wdve.jpg

    DSC_2042s_zpsmleigpcl.jpg
     
  7. Dec 8, 2015 #6

    davenn

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    much more realistic and lots more detail :smile:


    Dave
     
  8. Dec 11, 2015 #7
    Andy, Nice photos, well done.
    I'm quite new to this type of imaging, so wondering if you could elaborate on the meaning of these numbers / settings?

    Is it: number of shots / f-stop / total time / shutter speed / ISO?

    Regards,

    Noel.
     
  9. Dec 11, 2015 #8

    Andy Resnick

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    Sure- sorry for any confusion.

    when I write, for example, '800/5.6', that means I used an 800mm focal length lens at an f/# of 5.6. Similarly. '10s ISO 2000' means each exposure lasted 10 seconds and the camera ISO was set to 2000, and I stacked individual frames to give a total exposure time of 50 minutes, or 14 minutes, or whatever.

    How has your astrophotography experience been so far? There's a fair number of experts here who have helped me get better.
     
  10. Dec 12, 2015 #9
    Thanks Andy. I forgot about the focal length. That makes perfect sense.

    My experience so far is ... limited. I spend an amount of time in a Dark Sky Reserve in the south west of Ireland (Kerry), which is fantastic. When the skies are clear, it is amazing, but given that it is the south west of Ireland, there aren't many good viewing night :). So great views, but lots of cloudy nights.

    Regards,

    Noel.
     
  11. Dec 12, 2015 #10

    davenn

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    start off with some Milky Way pics ... camera, tripod and a wider angle lens, say 50mm or less, preferably down around 20mm give or take a bit
    depending on your camera make and model, hopefully it can do long exposures up to 30 sec and are able to swap lenses (dSLR)

    One great lens is the Samyang 14mm f2.8, produces really nice wide angle images
    here's an example from a thread I started several months ago ...
    https://www.physicsforums.com/threads/milky-way-pic-with-new-lens.832236/

    get out there and start imaging and show us your results :)
    post the camera settings used ... focal length, f-stop, ISO, shutter speed
    resize images to around 1000 pixels on the long side and compress to around 80 - 85%
    to limit their physical kb size

    cheers
    Dave
     
  12. Dec 15, 2015 #11
    Thanks Dave and excellent photo on the other thread. I'm super impressed that you can get that type of result from a single image. I'll count that as a target to aim for :)

    Regards,

    Noel.
     
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