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Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

cnet.com

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Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#11

Post by chmod775 »

derefr wrote: post #7
ben7799 wrote: post #4

Earlier quoted context omitted.

Insane Contrast ratio - ultra bright sunlight when the sun gets in the frame (no atmosphere to diffuse light) plus ultra dark hard shadows as the light source is millions of miles away, and again no atmosphere to diffuse the light. Again ultra dark, so the camera needs to have an incredibly sensitive sensor. And incredible motion, the spacecraft is whipping by the asteroid quickly.. so you'd need a fast shutter speed…

> no atmosphere to diffuse light Could the spacecraft—just in theory— introduce an atmosphere? Maybe not this spacecraft, but if we’re riding around in the starship Enterprise and want to get better snaps of asteroids, would it be a good idea to just send out a big pair of glass hemispheres, encapsulate the asteroid with them, pump them full of air, and then take a picture of the asteroid-capsule system? Alternately,…

If your spaceship is sufficiently large you could just point a lot of lights from different angles at the smaller asteroid to get the same effect.

Alternatively point a light strong light at yourself, so it is diffused back at the asteroid evenly. Photographers have used this trick for ages.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#13

Post by gus_massa »

ben7799 wrote: post #4
Havoc wrote: post #2

Why are the pictures so fuzzy?

Insane Contrast ratio - ultra bright sunlight when the sun gets in the frame (no atmosphere to diffuse light) plus ultra dark hard shadows as the light source is millions of miles away, and again no atmosphere to diffuse the light. Again ultra dark, so the camera needs to have an incredibly sensitive sensor. And incredible motion, the spacecraft is whipping by the asteroid quickly.. so you'd need a fast shutter speed…

> Again ultra dark, so the camera needs to have an incredibly sensitive sensor.

Is it so dark? IIUC the asteroids is almost at the same distance from the Sun than Earth (something like a 50% more) so the illumination should be similar (about a half, but a glass that blocks half the light looks totally transparent at sight, it's weird to measure it experimentally). Is the soil of the asteroid too dark? Like what? Grounded coffee?

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#14

Post by gbrown »

derefr wrote: post #7
ben7799 wrote: post #4

Earlier quoted context omitted.

Insane Contrast ratio - ultra bright sunlight when the sun gets in the frame (no atmosphere to diffuse light) plus ultra dark hard shadows as the light source is millions of miles away, and again no atmosphere to diffuse the light. Again ultra dark, so the camera needs to have an incredibly sensitive sensor. And incredible motion, the spacecraft is whipping by the asteroid quickly.. so you'd need a fast shutter speed…

> no atmosphere to diffuse light Could the spacecraft—just in theory— introduce an atmosphere? Maybe not this spacecraft, but if we’re riding around in the starship Enterprise and want to get better snaps of asteroids, would it be a good idea to just send out a big pair of glass hemispheres, encapsulate the asteroid with them, pump them full of air, and then take a picture of the asteroid-capsule system? Alternately,…

The gravity likely isn't strong enough to hold the atmosphere. Also, that's a lot of material. A large white solar sail style diffuser might work, or even easier a really really powerful flash (probably explosive based).

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#17

Post by gruturo »

derefr wrote: post #7
ben7799 wrote: post #4

Earlier quoted context omitted.

Insane Contrast ratio - ultra bright sunlight when the sun gets in the frame (no atmosphere to diffuse light) plus ultra dark hard shadows as the light source is millions of miles away, and again no atmosphere to diffuse the light. Again ultra dark, so the camera needs to have an incredibly sensitive sensor. And incredible motion, the spacecraft is whipping by the asteroid quickly.. so you'd need a fast shutter speed…

> no atmosphere to diffuse light Could the spacecraft—just in theory— introduce an atmosphere? Maybe not this spacecraft, but if we’re riding around in the starship Enterprise and want to get better snaps of asteroids, would it be a good idea to just send out a big pair of glass hemispheres, encapsulate the asteroid with them, pump them full of air, and then take a picture of the asteroid-capsule system? Alternately,…

Wouldn't it be immensely more practical to match course and speed, have the object perfectly still relative to you, then take multiple pictures at different exposures and assemble them into an High Dynamic Range picture? Then if you really feel like it you can apply a diffuse filter to it.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#18

Post by derefr »

gbrown wrote: post #14
derefr wrote: post #7

Earlier quoted context omitted.

> no atmosphere to diffuse light Could the spacecraft—just in theory— introduce an atmosphere? Maybe not this spacecraft, but if we’re riding around in the starship Enterprise and want to get better snaps of asteroids, would it be a good idea to just send out a big pair of glass hemispheres, encapsulate the asteroid with them, pump them full of air, and then take a picture of the asteroid-capsule system? Alternately,…

The gravity likely isn't strong enough to hold the atmosphere. Also, that's a lot of material. A large white solar sail style diffuser might work, or even easier a really really powerful flash (probably explosive based).

Well, yeah, that’s why I mention encapsulating the thing in a glass ball or somesuch first, to hold the air in as it’s pumped over. Make a gatcha/Kinder Surprise asteroid. Obviously impractical, but I really like the image of it.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#20

Post by jandrese »

derefr wrote: post #7
ben7799 wrote: post #4

Earlier quoted context omitted.

Insane Contrast ratio - ultra bright sunlight when the sun gets in the frame (no atmosphere to diffuse light) plus ultra dark hard shadows as the light source is millions of miles away, and again no atmosphere to diffuse the light. Again ultra dark, so the camera needs to have an incredibly sensitive sensor. And incredible motion, the spacecraft is whipping by the asteroid quickly.. so you'd need a fast shutter speed…

> no atmosphere to diffuse light Could the spacecraft—just in theory— introduce an atmosphere? Maybe not this spacecraft, but if we’re riding around in the starship Enterprise and want to get better snaps of asteroids, would it be a good idea to just send out a big pair of glass hemispheres, encapsulate the asteroid with them, pump them full of air, and then take a picture of the asteroid-capsule system? Alternately,…

This shot was taken from 9m away. A powerful camera flash would have been sufficient. It fact it seems like a bit of a missed opportunity not to have a handful of powerful but tiny LEDs on the spacecraft and take shots with different lighting to try to get the most detail out of this as possible. Yes you need to be quick, but this can be designed.
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