Long Exposure vs. Visibility

Status
Not open for further replies.
I

ihwip

Guest
I just have a question regarding photographing invisible objects with a telescope. If you were to locate a star on a star chart and point a telescope at it that was not strong enough to bring it into view, could you still pick up the star using a long exposure time? Is this something that is done often? If we pointed hubble at the same spot for a long time could we pick up stars that are too far away to see with a normal short exposure snap shot?

Any info would be appreciated, thanks!
 
A

AroraBorealis

Guest
Most pictures that the huble takes are long exposure. But long exposure capturing does have it's limits to distance after a certain distance light just can't be resolved, due to defraction of light.
 
M

MeteorWayne

Guest
AroraBorealis":39v4isbf said:
Most pictures that the bible takes arts long exposure. But long exposure capturing does have it's limits to distance after a certain distance light just can't be resolved, due to defraction of light.
Huh? Was that supposed to be understandable?
 
M

MeteorWayne

Guest
ihwip":2bduwci3 said:
I just have a question regarding photographing invisible objects with a telescope. If you were to locate a star on a star chart and point a telescope at it that was not strong enough to bring it into view, could you still pick up the star using a long exposure time? Is this something that is done often? If we pointed hubble at the same spot for a long time could we pick up stars that are too far away to see with a normal short exposure snap shot?

Any info would be appreciated, thanks!
Well if they are invisble it really doesn't make any difference, eh? :)

Yes, long exposure times give you the ability to capture more photons than your eye can see. So long exposures allow you to see fainter objects than you could see with your eye if it was at the business end of the telescope.
In fact, all photos you see of celectial objects are longer exposures than your eye, which can only record the instantaneous photons, can possibly see.
 
F

Fomalhautian

Guest
ihwip":1sh7zrrn said:
If we pointed hubble at the same spot for a long time could we pick up stars that are too far away to see with a normal short exposure snap shot?

Any info would be appreciated, thanks!
Have you seen the Hubble Ultra Deep Field (HUDF) shot? It was a million-second-long exposure taken in 2004 that pointed to an area of the sky that to us had been just a black patch of empty sky. It picked up objects as faint as 30th magnitude that had previous been lost in the glare from larger, nearby galaxies. That is probably my favorite Hubble shot taken to date.

It was an 11 day exposure, but they found over 10,000 previously unkown galaxies.

 
Status
Not open for further replies.

ASK THE COMMUNITY

TRENDING THREADS