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Astronomy Photographer of the Year
September 10, 2011 4:55 AM   Subscribe

Astronomy Photographer of the Year The Royal Observatory has announced the Astronomy Photographers of the Year for 2011. A BBC slideshow talks you through the category winners, casting more light on the judges decisions. posted by biffa (20 comments total) 13 users marked this as a favorite

 
So... this beautiful "photo" of Jupiter and two moons is a... montage? Why not just photoshop in all of its moons?

Except Europa of course

Yeah yeah eponysterical
posted by hal9k at 6:08 AM on September 10, 2011 [3 favorites]


Beautiful work, all of them.

Hal9k, almost all astrophotography is manipulated in some way these days. One very common technique is to take a brief video of a scene, separate it into individual still frames, discard frames that are blurry or noisy, and then align and "stack" the remaining frames to bring out as much detail as possible. An amateur with around $500 worth of equipment and armed with these techniques can get more detailed planetary images than any astronomer in the world had access to back in the 1980's. (Though deep sky targets take more expensive gear, and these folks are likely using setups costing at least several thousand dollars, in most cases.)

One of the guys from my local astronomy club is doing really neat work with combining terrestrial and celestial scenery. I always love to see what people come up with.
posted by richyoung at 6:17 AM on September 10, 2011


I wish there were higher res versions.
posted by Paris Hilton at 6:33 AM on September 10, 2011


*right click* > use image as desktop picture.
posted by Devils Rancher at 8:43 AM on September 10, 2011


richyoung, we accept that astrophotography requires image processing. But photoshopping moons into positions they weren't, is misrepresentation. You do that in news photography and you lose your job, even if you won a Pulitzer Prize. I am disappointed in the Royal Observatory judges.
posted by charlie don't surf at 8:55 AM on September 10, 2011


It's not clear to me the moons have been repositioned. Where does it say that?
posted by edd at 8:59 AM on September 10, 2011


Scrap that - just found it.
posted by edd at 9:01 AM on September 10, 2011


This one from the Earth & Space category winner's Flickr stream is even more ridiculous than the winning entry.
posted by wreckingball at 10:35 AM on September 10, 2011


Think decoration, not science.
posted by Cranberry at 10:39 AM on September 10, 2011


APOD gets fooled sometimes too. I was annoyed enough by the taunting "True Image" title and vehement online defenses of its authenticity by Pacholka and others that I did some pretty serious digging to determine if it was physically possible to take this photo as described. No surprise to me that it wasn't.
posted by Lazlo at 10:50 AM on September 10, 2011


blah... where is RBA? i think he's the best, anyway.

deep sky colors ...he's got like 3 billion nasa APODs to his credit... i've never seen so many good shots of the integrated flux nebula before.
posted by joeblough at 11:59 AM on September 10, 2011


oh as an astrophotographer myself i have to point out that these pictures are not the result of pointing your camera at the sky and snapping a picture. *

for "deep sky" work, the final pictures are almost always a "stack" of 10-100 individual exposures. the subexposures can be as short as 60s and as long as 30minutes or more. because of the long exposures, you need a mount which is aligned to earth's polar axis and rotates to undo the rotation of the earth. usually you also need a guiding camera, which will watch a star near your field of interest and send corrections to the motors in the mount to keep the stars perfectly centered. the longer the focal length the more critical guiding and tracking becomes.

in the case of planetary imaging, people often use webcams or point and shoot cameras in movie mode. the resultant images can be the result of 1000s of frames, which are analyzed for quality and stacked. because atmospheric distortion can really mess with your images, software like registax actually breaks the images down into polygons and realigns each polygon across frames.

that's probably why the jupiter image is a composite (if it really is). after a few minutes jupiter will have rotated a significant amount and no matter how good your tracking/guiding is, the image will be messed up - you aren't taking a picture of the same thing anymore. also the moons also whip around in their orbits and are themselves rotating (though perhaps they are tidally locked to jupiter.) if it is a composite the moons were probably put back to where they were in the "reference" frame (most likely the clearest/sharpest frame of the lot)

the reason you use stacking in the deep sky case is that the signal is very faint and by averaging a lot of frames you can "know" the true value of a pixel much better. if you look at the histogram of one of these stacks, all of the data is crammed down into the left hand side, and you have to use curves and levels to "stretch" the histogram out. so that the data can be seen. this is where the true art of astrophotography lies - it's hard to bring out the details without blowing the highlights, for instance.

another related reason for stacking: if you intentionally shift your images by a few pixels each time you can more easily reject sky noise and sensor (heat noise) while stacking.

* sometimes the milky way shots you see are - with a wide enough lens you can take a single frame without tracking that looks pretty good.
posted by joeblough at 12:19 PM on September 10, 2011 [3 favorites]


I guess I don't think of things like the "True Image @ False Kiva" shot as "fake." It's a composite showing stuff our eyes are too dynamic-range-limited to perceive. I can't imagine a photographer claiming that any of these photos represent what the subject actually looked like that with human eyes - that would be ridiculous. But the Milky Way really was there, in that orientation (right? or are you saying the galactic view wasn't collected at that location?). You would have seen something very like the APOD image if there were little or no atmosphere present.

Sometimes, the point of an image is pure science. Other times, the purpose is art, or outreach (to get people interested in astronomy). These purposes are not mutually exclusive. But dissing artistic terrestrial astrophotography because it's composited is like dissing bluegrass because it's got too much fiddle.
posted by richyoung at 12:34 PM on September 10, 2011


I think it is possible to get a picture of Jupiter and multiple moons. Such an alignment is fairly common, here's a simulation of an alignment with Europa and Ganymede (repeat: computer simulation). Here is a real photo of Ganymede and Jupiter, but that's from Hubble so it has an unfair advantage over terrestrial astrophotographers.

And yes, the winner is a composite, if you listen to the BBC slideshow, near the very end it says the satellites are separate images.
posted by charlie don't surf at 12:35 PM on September 10, 2011


it's not that it's not possible to get a picture of the moons together like that, it's just that it's probably easier to do each one separately. could use a longer focal length on the moons, for instance.
posted by joeblough at 12:52 PM on September 10, 2011




There are a lot of contenders for the most beautiful photo of Saturn. The Cassini Hall of Fame is wonderful.
posted by charlie don't surf at 4:26 PM on September 10, 2011 [1 favorite]


Hey kid, are you going my way?
Hop in, we'll have ourselves a field day
We'll find us some spacegrass,
Lay low, watch the universe expand
Skyway, permanent Saturday
by the way, Saturn is my rotary
Hop in, it'll be eternity
Till we make it to M83
posted by FatherDagon at 11:10 PM on September 11, 2011


I guess I don't think of things like the "True Image @ False Kiva" shot as "fake." It's a composite showing stuff our eyes are too dynamic-range-limited to perceive. I can't imagine a photographer claiming that any of these photos represent what the subject actually looked like that with human eyes - that would be ridiculous. But the Milky Way really was there, in that orientation (right? or are you saying the galactic view wasn't collected at that location?).

It's plausible, even likely, that the sky and landscape were photographed from the same location, just not at the same time. There are a number of inconsistencies (to put it politely) between the photo and the photographer's description of how and when he took it, but suffice it to say that on the dates when Jupiter was in that position in Sagittarius, and the times when the Milky Way was in that position in the sky as seen from False Kiva, there was no light source available that could have cast the shadows seen on the landscape.

Most likely the landscape was photographed shortly after sunset, and the Milky Way was photographed around two-and-a-half hours later, with the two combined after the fact. This would be fine if it were presented it as a composite...but as linked above, the photographer explicitly and emphatically states that it's not a composite, but rather four vertical shots stitched into a single panorama.

Seeing APOD's imprimatur on such a horrific Photoshop job was really disappointing.
posted by Lazlo at 6:35 PM on September 19, 2011




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