Andromeda Galaxy from Portsmouth, UK

Discussion in 'Astrophotography' started by Levster, Nov 1, 2015.

  1. Here is my quick (26 exposures) and dirty (no darks or flats) shot of Andromeda. I'm still learning how to post process these and seem to lose all colour information in the process! The shots were taken on a particularly hazy night in the centre of (what is claimed to be) the most densely populated city in the UK. This was taken with my GX-8 with 26 exposures at 1600ISO and 1 minute exposures:

    Last edited: Nov 15, 2015
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  2. 50orsohours

    50orsohours Mu-43 Hall of Famer Subscribing Member

    Oct 13, 2013
    Portland Oregon
    Wonderful shot!
  3. I was out last night again and this time took 32 shots, with each shot lasting 2 minutes at ISO1600. I also took 10 dark frames and 10 Bias frame, all combined in Deep Sky Stacker and processed in Photoshop, the results (and a comparison with my previous effort is below:

    View attachment 446644 All Photos-237 by -the-levster-
    Last edited: Nov 15, 2015
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  4. m4/3boy

    m4/3boy Mu-43 Veteran

    Jul 21, 2013
    Impressive! Kudos!
  5. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    I struggle w/ the same issue of loosing color data. I've made a bit of progress by examining the RAW conversion. Found it was boosting the image too much & blowing out the highlight colors. How are you doing RAW development? How are you stacking?

    Seems unlikely these are over exposed @ ISO 1600 & f6.

    When I look at the 2 min. stack, there's color but only around star edges & it looks like lens fringing.

    Also wondering how the GX8 does w/ long exposure noise. I'd love to get a RAW dark frame from you to boost & look at long exposure noise.
  6. I stack in DeepSkyStacker but when it comes to the final tweaks I've tried to follow a few online tutorials with occasional success. I'm in the process of selling my GX8, and I'm now back with an E-M5ii. That last shot was with my E-M5ii.
  7. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    I'm on a Mac so don't use DSS but as I recall, it does RAW development & has many controls to adjust the image. Think it has something like highlight recovery. Have you tried using those?

    I've run into the serious limitations imposed by long exposure noise. Have you seen Brendan Davey's discussion of long exposure noise? He has some sensor tests here: Long Exposure Sensor Testing. That's why I was interested in seeing your GX8 Raw dark frame. Davey has not tested many m43 cameras.

  8. I'll see what I've got, that first shot with the GX-8 didn't have any darks or bias frames and I can remember if I did take any later. I'll check after work.
  9. Here is a single 60 second dark frame as 1600 ISO:

    Dropbox - P1000537-8.RW2
  10. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Thanks, I'll take a look.

    In a few days, I'll be posting some test results for long exposure noise from my E-M5.
  11. I stacked and edited the 2 min stack again, but this time with a flat frame as well (I'm really not sure how much difference these make!).

    View attachment 447483 Andromeda_2min_flats-Edit.jpg by -the-levster-