Field of View

  • Thread starter big man
  • Start date
  • #1
253
1

Main Question or Discussion Point

I was just reading about the Hubble Telescope and I saw something saying that the planetary camera on it had a field of view of 2.5' x 2'.
I don't actually know anything about astronomy so I was just curious what the field of view is? I found that the ' meant arcminutes, but that doesn' help me really with what the field of view is.

Cheers
 

Answers and Replies

  • #2
DB
501
0
well im not an expert on space photography but i know that an arc minute is 1/60 of a degree. space telescopes use arcminutes as units to measure extremely small angles because of the extremely large (relatively speaking) distances from the object they observe. think of it as a unit of distance like a radian of a circle: 2.5' by 2'. do u see it?
 
  • #3
253
1
so is it really just the angular area that the camera can cover?
 
  • #4
Labguy
Science Advisor
731
7
big man said:
so is it really just the angular area that the camera can cover?
Yes, it is called angular distension. One arc-minute is almost exactly 1 inch at 300 feet. Target shooters would throw away a gun that can't shoot 1" groups at 100 yards.

In space though, an arc-minute is quite large for some objects, so they are measured in arc-seconds (1/60th of an arc-minute, 1/3600th of a degree). I've seen a lot of double stars with a separation of only about 0.8 arc-seconds (homebuilt scope).
 
  • #5
russ_watters
Mentor
19,573
5,847
FYI, the moon is roughly 30' across, while Jupiter is roughly 30" across (variable).
 

Related Threads on Field of View

Replies
2
Views
3K
Replies
9
Views
4K
  • Last Post
Replies
8
Views
3K
Replies
2
Views
3K
  • Last Post
Replies
7
Views
1K
Replies
1
Views
3K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
876
Top