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Pictures of extraterrestrial space

  1. May 30, 2017 #1

    wolram

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    Do any of you have pictures of space objects, planets, moons, galaxies that have not been enhanced?
     
  2. jcsd
  3. May 30, 2017 #2

    berkeman

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    Google Images? The picture threads in the Astronomy forum? :smile:

    And what do you mean by enhanced? Is a timed, tracking exposure enhanced?
     
  4. May 31, 2017 #3

    davenn

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    indeed :smile: ... I find this an unusual/strange question ... @wolram ... what are you getting at ?

    again, indeed ... @wolram what is your definition of enhanced ? a little bit of sharpening ? a bit of colour correction ?
    or something much more involved ?

    MOST images, as they come off the camera, need some work else they are VERY bland and not worth looking at
    often due to light pollution


    Dave
     
  5. May 31, 2017 #4

    davenn

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    OK .... referring to my previous last comment ....

    you also need to understand that all professional photographers and most of us semipro and a large bunch of pure amateur happy snappers use RAW file format and just to view this file out side a image processing program means a little enhancement and conversion to a xxx.jpg file and this is regardless of if it is a astro photo or the photos of portraiture or landscapes

    have a look at these two images

    the first one is the xxx.jpg straight out of the camera that I took at home in the city with tons of light pollution, I can only see the brightest stars

    2015_03_28_3373sm.jpg

    seriously blah looking !!

    here below is the same photo, the RAW version edited in Lightroom to get rid of the light pollution and do just a little contrast
    and sharpening enhancement and finally a little cropping to get rid of the last of the vignetting and the corner of the house roof

    upload_2017-5-31_19-15-14.png


    Now, you tell me, which one would you prefer to look at ?

    Canon EOS 5D Mark III
    F/4
    30 sec exp
    ISO 800
    24mm focal length



    Dave
     
  6. May 31, 2017 #5

    russ_watters

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    Without being sure of where this is going...

    A common complaint of some purists is that brightening or darkening of a photo is "enhancement". It isn't real evident in @davenn's photo (indeed, I'd suggest more...still nice though), but it is done by stretching the data and cuting off the low end greyness to make the background black while also brightening the middle and bright side. Mathematically, this technique is identical to scaling a graph so it shows the data stretched out instead of bunched-up at the bottom of the graph. Is that "enhancement"?

    Similarly, a basic contrast adjustment changes the shape of the graph (photo brightness curve) in a way similar to choosing a linear vs logarithmic scaling on a scientific graph. Of course, there are more complex options for scaling a photo's brightness curve...

    What about color correction? Whether done on purpose or not, all photos are shot in separate colors and then combined in software to produce a color image. And because the chip sensitivity isn't the same for different colors, either the exposures have to be made different for each color (common in astrophotography) or the colors corrected by the software (regular photography).

    How about false colors? Any data can be mapped to colors for visual representation. It's common in CFD analysis, for example. But most direct would be mapping infrared light to visible. So are false colors really "enhancement"?

    How about running an experiment/taking a photo 10 times and then averaging the data...?

    Or, rather, is "enhancement" really a negative thing?

    When it comes to my photos I consider what I'm doing more art than science so utimately I don't care if they are judged to be over-processed unless that makes them look bad (in the extreme; I've put threads in front of my telescope to create diffraction spikes). But I still find people often have an incorrect view of what "processed" means for the scientific or realism value of a photo.
     
  7. May 31, 2017 #6

    collinsmark

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  8. Jun 1, 2017 #7

    davenn

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    that's where we differ :wink: I'm the exact opposite .... I like to produce my images, astro or earth landscape etc, to look as natural as possible. It's rare that I will over-process to head into the "art realm"

    Wellllll .... if you are going to over-process them to produce art then from a natural look point of view they will look bad hahaha
    but from an art point of view, anything goes and there is no limit to what a person wants to do with an image.

    MY pet peeve is when people over-process and then don't state that it's art and not reality.
    Many photos I see are like that. I just would like people to state their intentions ... is it science/capturing nature or art

    I don't care which way a person leans in that process, just don't try and pass off an arty look for realism :rolleyes:

    Don't tear it to bits too hard, I only spent 10 mins on that image, it was just some real quick processing to point out to @wolram the difference between out of camera and getting some decent data out of an image ... the difference is obvious

    Dave
     
    Last edited: Jun 1, 2017
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