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2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

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Re: 2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

#61

Post by db48x »

kzrdude wrote: post #59
mixmastamyk wrote: post #56

I've never been a fan of the obligation to crank the saturation through the roof on astronomy images. I think it leads to unrealistic expectations. Any links to a more natural view?

Isn't this a never-ending discussion? There is no natural when you go past the naked eye. Any camera has a "filter", a development technique is a "filter"

Agreed. Without long exposures, nebulas are all but invisible. Even if you were inside of one, it would still be essentially invisible. They're really diffuse objects; the inside of a nebula is still a hard vacuum.

Re: 2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

#62

Post by dheera »

kzrdude wrote: post #60
dheera wrote: post #22

Earlier quoted context omitted.

Orion is home to a whole bunch of stuff that the human eye cannot see that you see in this photo, especially Barnard's Loop and the Lambda Orionis Ring, which together occupy pretty much the entire size of the constellation. They are huge objects in the night sky, yet at H-alpha wavelength they appear too dim to the naked eye to see. I've been doing a lot of landscape astrophotography lately in which I show these obj…

Awesome. Is that picture taken with a regular DSLR type camera?

Yep, although I ripped the IR filter out, because the stock IR filter on consumer cameras cuts off the Hydrogen alpha wavelength (656.3 nm) which is what most of those red nebulae are.

Re: 2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

#63

Post by mixmastamyk »

kzrdude wrote: post #59
mixmastamyk wrote: post #56

I've never been a fan of the obligation to crank the saturation through the roof on astronomy images. I think it leads to unrealistic expectations. Any links to a more natural view?

Isn't this a never-ending discussion? There is no natural when you go past the naked eye. Any camera has a "filter", a development technique is a "filter"

Please, letting in a more light is nothing like cranking the saturation so high that grey turns to bright red.

Re: 2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

#64

Post by geon »

crazygringo wrote: post #53
Tuna-Fish wrote: post #29

Earlier quoted context omitted.

There are no pure black areas between stars, and that's not (just) sensor noise. It's not very wrong to say that every single pixel in that image holds at least one galaxy. If you collect enough light, you will find something interesting to look at.

At some point the sensor noise swamps any signal, given your setup and processing. So from a philosophical view every pixel holds a galaxy, but from a practical point of view sensor noise obliterates it. I think it's reasonable to call the area in between visible stars "black" when received light is below the noise floor.

I’m guessing that it is difficult to distinguish the “noise” of sub pixel galaxies from the thermal noise of the sensor.

Re: 2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

#65

Post by ra »

kzrdude wrote: post #8
SXX wrote: post #4

Image itself in high resolution can be found here: https://orion2020v5b.spaceforeverybody.com/

I was looking for galaxies, and then I turned on annotations. There's a ton of PGC annoations (galaxy catalogue) and it helps you see many of them; however many of them don't seem to be visible at all in the picture (there's too many of those PGC annotations?) Either way, very cool, that helps getting the eyes up for the galaxies scattered in the picture.

I've just zoomed in randomly on a couple of places and in each frame there's a handful of side on spiral galaxies... it's very cool - take another look?

Re: 2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

#67

Post by vl »

Tuna-Fish wrote: post #29
crazygringo wrote: post #25

Earlier quoted context omitted.

Good observation. I assume that's because it's "overexposed" to bring out the nebulas etc.? Zooming in all the way, the pure "black" areas between stars also seem to have a fair bit of sensor noise that probably plays a part too.

There are no pure black areas between stars, and that's not (just) sensor noise. It's not very wrong to say that every single pixel in that image holds at least one galaxy. If you collect enough light, you will find something interesting to look at.

It’s not exactly correct though: at this resolution - maybe, but at resolution high enough there are gaps between galaxies. The reason for that is that region of space we can observe is finite. If it would be infinite, and between any two objects we would see one more object, all we would is see is uniform white.

Re: 2.5 Gigapixel Image of the Orion Constellation Took 5 Years to Complete

#68

Post by dylan604 »

alok-g wrote: post #43
irrational wrote: post #41

Earlier quoted context omitted.

https://www.nationalgeographic.com/science/phenomena/2015/04...

Wow!

I love that this is your reaction to that story, as I believe that is the only valid reaction! I also love being reminded that every day someone gets to experience something new that I've already taken as fact.
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