This image of home just came down from the Artemis II crew.
Taken after their translunar injection burn, there are aurorae at top right and lower left, and zodiacal light at lower right.
Credit: NASA/Reid Wiseman
// That’s home. That’s us.
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Alternative references of better image quality mentioned in comments by @baguette@piefed.social:
- https://images.nasa.gov/details/art002e000192;
- https://images-assets.nasa.gov/image/art002e000192/art002e000192~orig.jpg [5568 x 3712]
Anyone know if the grain is due to radiation or just ISO?
This is on the night side of Earth, so lit only by moonlight. It’s grain from long exposure.
Thanks!
Wouldn’t a long exposure have less grain? Usually it’s short exposure and high ISO that results in grain.
Less grain than a shorter exposure? Absolutely. Due to motion you still have to cap exposure duration to a somewhat small number or you’ll start getting light streaking. It would be very interesting to see the exif information for this photo.
It is there:
it is the high iso that produces the visible grain.
long exposure time would have less grain, but to use it, you need for the scene to not move long enough.
the movement and subsequent blurred image is introduced by two different things. either the scene itself is moving, or it is the camera that is moving (your shaky hand, or the spaceship doing 20000+ km/h.
if the scene is not moving and you can use tripod to stabilize the camera movement, then you can use long exposure time and however low iso you want.
if this is impossible, because tripod in a spaceship would still not help shaking the camera relative to phographed object that is outside of the spaceship, then short exposure time (and high iso to compensate for that) is your only choice. (and still, even with the super high iso, it still was 1/4s. i suspect some stabilization in the lens.)
https://digital-photography.com/camera/aperture-exposure-time-iso-understanding.php
They left the EXIF data in the file, you can see the huge ISO. Really interesting lens also.
EDIT: I’ve now seen this is actually the night side, so it checks out.
This is full of interesting but slightly puzzling information.
First, it’s shot at 22mm, which is a pretty wide angle, so I guess they were still pretty close when they took it.
What’s really puzzling to me though, is why did they need to crank up the exposure so much?
We’re looking at 51k ISO @ f4, I can shoot in really dark places with this kind of ISO (but I don’t, because it looks like trash).
They seem to be shooting the day side of earth as far as I can tell, so I don’t really understand why they needed that much sensitivity, instinctively I would’ve assumed you’d only need the same kind of settings you’d use on daytime exteriors here on earth (so nowhere near that ISO).
It looks like the daytime side because the ISO is cranked up that high.
This is the nighttime side, only lit by reflected moonlight. The sun is behind earth on the bottom right.
They wanted to fire off that first shot as soon as all of earth fit in the window, instead of waiting 12 hours.
Yeah I realized that afterwards. At the end of the day moonlight is basically just sunlight but dimmer (also something you learn when trying to shoot night scenes), that’s why we can shoot “day for night” and it looks mostly correct.