Starship Asterisk*

by **charlieo3** » Fri May 02, 2014 3:12 pm

OK, John. Thanks for the background info and the photography lesson.

by **superwillbee** » Fri May 02, 2014 10:32 am

Being partially colorblind i am quite aware that it's totally unclear what different persons see, looking at 'reality'. So basically there can't be a universal, common image of reality. The use of different camera's, lenses etcetera adds even more doubt about this 'reality'. Reality is quite questionable.
But i am still wondering about the stars. How come they all seem to have more or less the same magnitude? Is it the Fish-eye lens together with the 15 seconds exposure? Have the stars been over-exposed?
Still a beautiful image though. Thanks for sharing it.

by **Anthony Barreiro** » Fri May 02, 2014 4:58 am

Thanks for the technical info John, and for the image.

by **geckzilla** » Fri May 02, 2014 2:13 am

Thanks for that info, John. So the diffraction spikes are real, huh? I guess we have something to learn about photography, then.

by **JohnChumack** » Fri May 02, 2014 1:53 am

The Aurora image has not been Altered to make it look like a dog, it has been color balanced only to get the natural color temperature of the stars, and Labelled to ID the stars & Planets. I saw this with my eye and had several cameras shooting at different parts of the Aurora, it changes rapidly..literally every 20 seconds or so..
For this shot I used an 8mm Fish-eye Lens with a Modified (Baader) Canon Rebel Xsi DSLR, ISO 1600, F3.5,for a 15 second exposure.
The Combination of this lens and modified Camera makes them super sensitive to starlight, hence why it is geared towards Astrophotography!

The 8 Spikes on the stars are often from Leaf Shutter stops or you can also employ a Star Cross filter.... I imagine it could be done post processing as well.
you can see the diffraction spikes on a normal lens if you stop down the F-stop to F6 or F8.
If fact with my 8mm Fish-eye lens Daylight is way too much light with this combo...
I literally have to stop way down to F32 and take super short 1/2000 to 1/4000 sec exposures at low ISO, but Most Experience Astrophotographers who own Fisheye lenses are aware of this!

Best Regards,
John Chumack
http://www.galacticimages.com

by **charlieo3** » Fri May 02, 2014 12:21 am

geckzilla wrote:this photo is still a good representation of reality. The stars being given faux diffraction spikes doesn't change the fact that all of this light from the aurora did hit a camera sensor. For what it's worth, your very own eyes and brain are in fact not very good at showing you reality. Your brain is its own processing center and it actually introduces all sorts of bias. Funny, isn't it?

As soon as I saw eight spikes sticking out of Mars and Jupiter (it took maybe all of three seconds to notice that), my brain said, "This is not a good representation of reality." Touchup work or enhancements to a photo are generally done to improve it. Unfortunately, in this case - imho - they were disappointingly unnecessary.

by **geckzilla** » Thu May 01, 2014 3:35 pm

superwillbee wrote:The heavily processed star-images make you wonder about the rest of the picture. What was really visible to the naked eye? The colours of the stars have been processed too, i think. So what was the original colour of the aurora? Personally, i prefer the less processed images. It's nature you know, it's reality you wan't to show(I hope). So keep it as real as possible.
But of course i know it is rather common to heavily process astronomy pictures, and it's still a nice example of the aurora, even though it's not reality.

He had to be able to see it pretty clearly with his eyes in order to take note that there was a dog in the sky to photograph. You could be looking at photos of a family reunion on your screen and they are every bit as unfaithful to reality as a snapshot of an aurora. That said, this photo is still a good representation of reality. The stars being given faux diffraction spikes doesn't change the fact that all of this light from the aurora did hit a camera sensor. For what it's worth, your very own eyes and brain are in fact not very good at showing you reality. Your brain is its own processing center and it actually introduces all sorts of bias. Funny, isn't it?

by **superwillbee** » Thu May 01, 2014 10:09 am

The heavily processed star-images make you wonder about the rest of the picture. What was really visible to the naked eye? The colours of the stars have been processed too, i think. So what was the original colour of the aurora? Personally, i prefer the less processed images. It's nature you know, it's reality you wan't to show(I hope). So keep it as real as possible.
But of course i know it is rather common to heavily process astronomy pictures, and it's still a nice example of the aurora, even though it's not reality.

by **DavidLeodis** » Wed Apr 30, 2014 6:50 pm

Nitpicker wrote:
do_japan wrote:Does anyone know which stars appear close to the horizon? The two bright orange ones on the right, and the cluster rising out of the trees near the center.
I think they are all artificial light sources on the ground. (The trees near the centre appear backlit.)

In the information about the image that was brought up through the 'John Chumack' link in the explanation it states "The Dome glow at the bottom above top of Trees is the Light Pollution from Fairbanks, 40 miles away!".

by **Nitpicker** » Wed Apr 30, 2014 3:10 am

do_japan wrote:Does anyone know which stars appear close to the horizon? The two bright orange ones on the right, and the cluster rising out of the trees near the center.

I think they are all artificial light sources on the ground. (The trees near the centre appear backlit.)

by **do_japan** » Wed Apr 30, 2014 2:55 am

Does anyone know which stars appear close to the horizon? The two bright orange ones on the right, and the cluster rising out of the trees near the center.

by **Chris Peterson** » Tue Apr 29, 2014 11:29 pm

superwillbee wrote:The magnitudes of the stars seem a bit strange. Procyon the same magnitude as the big dipper's main stars? Has the picture been fotoshopped? Or adapted in other ways?

Yes, this is clearly a processed image. That isn't how stars appear in simple images.

by **superwillbee** » Tue Apr 29, 2014 8:01 pm

The magnitudes of the stars seem a bit strange. Procyon the same magnitude as the big dipper's main stars? Has the picture been fotoshopped? Or adapted in other ways?

by **Anthony Barreiro** » Tue Apr 29, 2014 4:29 pm

Glorious. The stars and planets are so sharp! It's so easy to find the constellations that the sky seems almost unreal. I'm not criticizing the image, just sharing my first impression.

by **BillBixby** » Tue Apr 29, 2014 4:22 pm

Once the location of Jupiter being in the jog's front legs was pointed out, I could not see the dog/cat at all. My first and strongest impression is of the green frog looking at me. Peaked eyes, mouth and squat body. Must have more coffee so I can tell the difference between a dog and a frog.

by **LocalColor** » Tue Apr 29, 2014 3:48 pm

Run, Spot, Run. Good dog.

Thanks APOD.

by **Bellerophon** » Tue Apr 29, 2014 1:11 pm

The image has lots of details that support the dog interpretation. Look at Delta Virginis and you can tell the dog's gender.

by **CURRAHEE CHRIS** » Tue Apr 29, 2014 12:30 pm

Im thinking it's a Scottie

And with it glowing that funky green color it's probably been hanging around Three Mile Island here in my neck of the woods a little too long!! Lol

by **Starkm31** » Tue Apr 29, 2014 11:22 am

Substitute "kitty"for "dog", and we can all " be happy". Yes.

by **Boomer12k** » Tue Apr 29, 2014 11:17 am

the "ears" look more Cat Like to me.....

But that is a great looking shot and an interesting twist to an Aurora....

(and people put me down for seeing things in Nebula....HA!)
:---[===] *

by **Nitpicker** » Tue Apr 29, 2014 11:06 am

Leo and Leo Minor are slap bang in the middle. But me and the Maiden, and the Big Bear, the Sea Snake, the Crab and the Unicorn, all agree it looks like a dog. Woof.

by **gcal** » Tue Apr 29, 2014 10:41 am

I agree with RedFishBlueFish, it looks more like a cat. A cheetah, I think. Too bad Leo isn't in there somewhere.

by **RedFishBlueFish** » Tue Apr 29, 2014 10:06 am

What is most amazing, and - this being the internet - what is most likely true, is that this is a cat: Look at the shape of the head - especially the shape of the ears and snout.

The only real question: Bastet or Shashti.

by **Guest** » Tue Apr 29, 2014 8:24 am

It also include Canes Venatici.

by **starsurfer** » Tue Apr 29, 2014 6:47 am

I find it amusing that the image also includes Canis Minor.

Starship Asterisk*

APOD: Aurora Dog over Alaska (2014 Apr 29)

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