In today's APOD, we see the arc of Anthe, but the background has numerous star trails which seem to trace different trajectories, one is even curved.
Why is this?
Search found 15 matches
- Wed Sep 10, 2008 8:09 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Saturn's Anthe Arc (Background stars) (APOD 10 Sep 2008)
- Replies: 14
- Views: 3843
- Tue Nov 27, 2007 7:56 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Aurora in the Distance (APOD 19 Nov 2007)
- Replies: 38
- Views: 13464
- Tue Nov 27, 2007 7:18 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Aurora in the Distance (APOD 19 Nov 2007)
- Replies: 38
- Views: 13464
Only very low quality lenses produce lens flare that is the same color as the source. The flare is caused by internal reflections, which are off of antireflection coatings. Chris, the lens flare around the moon is white and red and large, but I doubt that the white flare is because this is a low qu...
- Tue Nov 27, 2007 6:55 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Aurora in the Distance (APOD 19 Nov 2007)
- Replies: 38
- Views: 13464
I agree with Chris. I've seen plenty of green and magenta flares off of my lenses from the coatings. snip.. Would you like to share an example of one of your flares with us that you think demonstrates this effect. And don't forget, the flare needs to point 'away' from the light source with its brig...
- Tue Nov 27, 2007 3:16 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Aurora in the Distance (APOD 19 Nov 2007)
- Replies: 38
- Views: 13464
Thank you all for the kind comments. The object near the moon is, as far as I know, nothing more than lens flare. I was using a 12mm lens at full aperture, and in my experience, pointed at a bright light source, this lens will definitely flare. snip.... Lance McVay lancemcvay@gmail.com http://sacre...
- Mon Nov 19, 2007 9:52 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Aurora in the Distance (APOD 19 Nov 2007)
- Replies: 38
- Views: 13464
- Tue Jun 12, 2007 6:11 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Shuttle Plume (APOD 12 June 2007)
- Replies: 7
- Views: 3371
It's a bit like the January Sales -- stuff has to be marked up first before it can be marked down for the sale. NASA is getting ready to signing on to doing their bit for Global warming - so they are getting plenty of slack in hand before being told to cut back on fuel usage. Chris O, you have a cra...
- Sun Jun 10, 2007 7:02 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: A Hole in Mars (APOD 28 May 2007)
- Replies: 109
- Views: 36891
To that end I have downloaded the full JP2000 format file from the APOD server (all 450MB of it) and will see what the file image holds. I downloaded the whole thing... only to discover that I couldn't find a working j2k plugin for my version of Photoshop. *sigh* :lol: Bear in mind, j2k will still ...
- Wed Jun 06, 2007 3:46 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: A Hole in Mars (APOD 28 May 2007)
- Replies: 109
- Views: 36891
Bear in mind that you're playing with JPEG images (unless you've found a source other than the one I did for these images), which means any region of 'solid' colour is going to be full of JPEG compression artifacts. So odds are, any detail you're going to bring up using brightness, contrast, or lev...
- Sat Jun 02, 2007 5:53 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: A Hole in Mars (APOD 28 May 2007)
- Replies: 109
- Views: 36891
- Sat Jun 02, 2007 5:38 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: A Hole in Mars (APOD 28 May 2007)
- Replies: 109
- Views: 36891
If this were the case, would have thought the HiRISE team would have thought of it already... Hi pj, I am sure that they have already done this and much more -- this is just bog standard image enhancement. I, and thousands of others, do this sort of manipulation every day to bring detail out of the...
- Sat Jun 02, 2007 1:29 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: I wiped my screen; waves on Titan sea? (APOD 30 May 2007)
- Replies: 4
- Views: 2679
- Sat Jun 02, 2007 12:53 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: humbling
- Replies: 2
- Views: 1914
I look at APOD every day and am amazed at the immensity of my power. Of all the life forms on this planet, this little ape can sit at his desk and inspect the cosmos from a distance that would take a billion lifetimes to travel, even at the speed of light. I can comprehend all that is mine to compre...
- Sat Jun 02, 2007 12:00 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: A Hole in Mars (APOD 28 May 2007)
- Replies: 109
- Views: 36891
Look into the DARK
The images posted can only be resolved into 13 levels of 'lightness' within the black of the 'hole'. The files posted have only 8 bit colour density resolution, that means the lightness can only be described in one of 256 steps of lightness (of which only 13 steps lay within the 'black' hole). Gener...
- Sat Jun 02, 2007 11:25 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: A Hole in Mars (APOD 28 May 2007)
- Replies: 109
- Views: 36891
Look into the dark
I think this is a hole, possibly a skylight and if you look carefully into the black you will see why I think this is the case. If the sun is indeed at a low angle and is coming from ca 7 o'clock - 8 o'clock direction and the thin Martian sky is not producing very much skylight then the effect shoul...