Celestial hemisphere:  Northern  ·  Constellation: Taurus (Tau)  ·  Contains:  The star 72Tau  ·  The star Alcyone (τTau)  ·  The star κ1Tau  ·  The star κ2Tau  ·  The star υTau
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Taurus Dark Cloud, David McClain
Taurus Dark Cloud
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Taurus Dark Cloud

Getting plate-solving status, please wait...
Taurus Dark Cloud, David McClain
Taurus Dark Cloud
Powered byPixInsight

Taurus Dark Cloud

Equipment

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Acquisition details

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Description

Old data, new processing

Canon EOS 6D + 200 mm F:2.8 @ F:5.6

We're right at the readout limits on this one. Definitely photon starved near the dark nebula. But I'm happy that a 1-inch aperture caught this much...

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Rev B: In this case, the field stars tell much of the story. So we ought not remove their impact as we so often do with other bright nebulae.

I have pretty much concluded that all processing for the Canon 6D and 200 mm lens should be done with drizzle integration. Rev B is a drizzled image from superpixel deBayering. Rev A was a VNC deBayering and no drizzle.

And while I do think that the ruddy background shown from extreme color stretching in Rev A is probably really there, the data just don't support it statistically. The background levels are so close to the readout noise floor that severe red / green micro-regions appear. Taken together over any sizable region of the image, those red / green islands cancel out to gray. But when you try to neutralize the "green noise" all that's left is red, and that gives rise to what I believe is a false impression of reddish background. Perhaps more and better data would support that result, but these data cannot.

I suppose that an argument could be advanced that since the micro-regions alternate green / red, and not green / red /blue, that there is a bias toward red, partially justifying the ruddy background presentation. Purely random readout noise should offer up an uncorrelated rainbow averaging to gray.

Comments

Revisions

  • Taurus Dark Cloud, David McClain
    Original
  • Taurus Dark Cloud, David McClain
    B
  • Final
    Taurus Dark Cloud, David McClain
    C

C

Description: okay... we really must remove the green stars...

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Taurus Dark Cloud, David McClain