Where are the turtles?
Artemis II crew take “spectacular” image of Earth
251–260 of 419 posts
Re: Artemis II crew take “spectacular” image of Earth
#252I was confused when I first saw this photo, as I don't think I've ever before seen a nightside, moonlit Earth, exposed so that it looks like the dayside at a first glance. I wonder how many casual viewers actually realize it's the night side. A nice demonstration of how moonlight is pretty much exactly like sunlight, just much much dimmer. In particular it has the same color, even though moonlight is often thought of…
Moonlight is reflected sunlight.
Reminds me of one of the best new comedy series in years, Very Important People, doing improvised spoof interviews:
https://www.tiktok.com/@veryimportantpeopleshow/video/731957...
Re: Artemis II crew take “spectacular” image of Earth
#253Earlier quoted context omitted.
You might misunderstand how ISO works on digital cameras. (I did.) https://www.youtube.com/watch?v=ZWSvHBG7X0w
Good grief, that video suffers the YouTube-ism of "ramble on about how you don't understand X" for way too long. Video alleges people think ISO makes the sensor "more sensitive or less sensitive". (I … don't think this is common? But IDK, maybe this is my feldspar.) (The video also quibbles that it is "ISO setting" not "ISO" … while showing shots of cameras which call it "ISO", seemingly believing that some of us bel…
i think we need to differentiate between raw or derivative format. canon KB might cater to wider audience thus the latter
Re: Artemis II crew take “spectacular” image of Earth
#254This picture wasn't taken from far away, but I thought about that quote from Carl Sagan -
Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.
The Earth is a very small stage in a vast cosmic arena. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.
Re: Artemis II crew take “spectacular” image of Earth
#255Earlier quoted context omitted.
> even though moonlight is often thought of as bluish and sunlight as yellowish! Is that... true? Sunlight is seen as yellow, of course, but the moon is usually thought of as white.
Sunlight is yellowish in atmosphere since some blue's been scattered by the atmosphere[1], but it's white in space. [1] https://en.wikipedia.org/wiki/Rayleigh_scattering
I don't think that's right. Sunlight is white in the atmosphere too. Scattering causes the sun, not the light, to look yellow, and so sunlight is thought of as yellow.
Re: Artemis II crew take “spectacular” image of Earth
#256I was confused when I first saw this photo, as I don't think I've ever before seen a nightside, moonlit Earth, exposed so that it looks like the dayside at a first glance. I wonder how many casual viewers actually realize it's the night side. A nice demonstration of how moonlight is pretty much exactly like sunlight, just much much dimmer. In particular it has the same color, even though moonlight is often thought of…
Thanks. Until you pointed out it's Earth at night , I had no clue what was supposed to be special about this photo (it appeared suspiciously pixelated for something 'high res', and neighbouring pixels seemed to contrast in colour rather than smoothly complementing as most photos do - but I guess that's random patches of city lights being captured by the camera). Cool stuff! Something I haven't figured out is: what is…
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Re: Artemis II crew take “spectacular” image of Earth
#257Earlier quoted context omitted.
You might misunderstand how ISO works on digital cameras. (I did.) https://www.youtube.com/watch?v=ZWSvHBG7X0w
Good grief, that video suffers the YouTube-ism of "ramble on about how you don't understand X" for way too long. Video alleges people think ISO makes the sensor "more sensitive or less sensitive". (I … don't think this is common? But IDK, maybe this is my feldspar.) (The video also quibbles that it is "ISO setting" not "ISO" … while showing shots of cameras which call it "ISO", seemingly believing that some of us bel…
ISO changes the analog gain and in a way yes, it does make it more sensitive to a certain range of brightness.
This is because the ADC (analog to digital converter) right after can only handle so many bits of data (like 12-16ish in consumer cameras). You want to “center” the data “spread” so when the “ends” get cut off, it’s not so bad. Adjusting the ISO moves this spread around. In addition, even if you had an infinite bitrate ADC, noise gets added between the gain circuit and the ADC so you want to raise the base signal above the “noise floor” before it gets to the ADC.
Gain is not great — it amplifies noise too. You want as low ISO as possible (lowest gain), but the goal is not actually to lower gain; your goal is to change the environment so you can use a lower gain. If you have the choice between keeping the lights off and using higher ISO versus turning on the lights and using a lower ISO, the latter will always have less noise.
Most photo cameras have one gain circuit that has to cover both dark and light scenes. Some cameras like a Sony FX line actually have two gain circuits connected to each photosite and you can choose, with one gain circuit optimized for darker scenes and the other optimized for brighter scenes. ARRI digital cinema line cameras have both and both are actually running at the same time (!).
Re: Artemis II crew take “spectacular” image of Earth
#258Looking at the EXIF (with exiftool) for the image uploaded by NASA ( https://www.nasa.gov/wp-content/uploads/2026/04/art002e00019... ), apparently this was taken by a Nikon D5 with an AF-S Zoom-Nikkor 14-24mm f/2.8G ED and developed with Lightroom. It also seems like very little was done in Lightroom. Amazing... I dumped the whole EXIF here: https://gist.github.com/umgefahren/a6f555e6588a98adb74eed79d...
Before Lightroom it might have looked closer to this: https://images-assets.nasa.gov/image/art002e000193/art002e00...
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Re: Artemis II crew take “spectacular” image of Earth
#259This is all we've got. We need to do a better job of preserving it.
Unfortunately that would affect shareholder value.
Re: Artemis II crew take “spectacular” image of Earth
#260Why didn't NASA or the news agencies rotate the image so North is up? and slightly to the right. That would make Africa instantly recognizable as that's how maps are imprinted in our brains. There is no "up" in space, so that wouldn't be editing the image I feel. The camera just happened to be oriented "upside down".
I personally prefer to view it in the same orientation the photographer saw it in their viewfinder. Makes me feel more like I’m inside the vessle looking at the planet.