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End of an era, can you polish a turd?

Discussion in 'Astrophotography' started by eteless, Aug 12, 2015.

  1. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    They've basically finished replacing all the street lights here with LED units and I was pondering the change of light pollution (thankfully within a certain radius of observatories they've made sure that LPS lighting is the only lighting used). Given the current trend and ignoring what may happen in the future, and that right now the sky now glows with a bright white light and there's not really any chance of a filter doing anything anymore, how much detail can you actually recover out of absolute rubbish?


    The picture isn't intended to be artistic so please do not comment on subject, it was purely to see how much detail remained in far far far from optimal conditions (clouds, on the edge of a city facing away, no smog at all). I used a (somewhat decentered, yet actually the best copy of this lens I've ever used) Canon EF 50mm f1.4 on metabones speedbooster on E-M1, this lens is not corrected into the UV range (I could have used a 1A filter, didn't) so there is huge flaring/contamination for many stars. The exposure was 4 seconds at t1.4 (f2.0 on lens) ISO 3200.

    unpolished-turd.
    The lighting in the area was enough that the trees are actually correctly exposed (despite having no direct light on them).

    polished-turd.

    I was actually surprised at how much detail remained from a single unstacked exposure, ignore the massive colour shifts which I didn't bother to mask and correct for (I choose this framing out of curiosity to see what the shifts would be given the method chosen for detail recovery). I found that if I pushed any harder than this I started to get lots of banding from the E-M1 phase detect pixels (there's already magenta bands forming), since it's a single short exposure with little information to begin with colour is also lacking.
     
  2. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    So, how much worse is this than before with the LPS lighting?

    Were you using a sodium filter before?

    Thanks!
    Barry
     
  3. tkbslc

    tkbslc Mu-43 Hall of Famer

    Most of us have to drive a ways to get decent astro shots, unfortunately.
     
  4. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    While I have used them for the most part they were not needed (that and they're ridiculously expensive in larger sizes for camera lenses), in the past the light pollution didn't travel like this. I don't know if it's a combination of higher powered / brighter lights but driving for hours and the sky is often still bright, It's basically impossible to find any clear sky anymore. Only a year or two ago I could travel slightly more than an hour and have absolutely no problems at all. I'm starting to think the only place which will have clear sky is looking at the ocean on a beach in the middle of nowhere, however even then I have my doubts.

    I think the problem is the white light, monochromatic light only lights up things that don't absorb it... white light always finds something to reflect off because it covers all the spectrum.
     
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