My telescope's field of view is tiny (about a quarter inch through the focuser w/ 25 mm eyepiece)

  • Stargazing
  • Thread starter Brian Muller
  • Start date
  • #1
I have an Orion 130 reflector. Never had a telescope before. The field of view is about a quarter inch through the focuser with the 25 mm eyepiece. Does anybody know what I am doing wrong or if there is something wrong with the telescope itself? I'm at my wit's end. Any help would be greatly appreciated.
 

Answers and Replies

  • #2
Bandersnatch
Science Advisor
2,968
1,935
Hi Brian, welcome to PF.
One thing that comes to mind is that the eyepiece is not inserted properly. Perhaps the mounting screws were not unscrewed fully before inserting the eyepiece, so that it sits higher in the focuser than it should (i.e. it's resting on the screws).
 
  • Like
Likes Brian Muller
  • #3
russ_watters
Mentor
20,249
6,842
I have an Orion 130 reflector. Never had a telescope before. The field of view is about a quarter inch through the focuser with the 25 mm eyepiece. Does anybody know what I am doing wrong or if there is something wrong with the telescope itself? I'm at my wit's end. Any help would be greatly appreciated.
"A quarter of an inch" doesn't really mean anything in this context, so it is tough to tell what you really mean. Did the scope come with a 10mm eyepiece too? Are you saying it's a worse view through the 25mm than the 10mm? What do you see when you look at the moon, for example; can you see the whole thing?

Do you have glasses or might your eye otherwise be too far from the eyepiece?
 
  • #4
Drakkith
Staff Emeritus
Science Advisor
21,105
4,933
I have an Orion 130 reflector. Never had a telescope before. The field of view is about a quarter inch through the focuser with the 25 mm eyepiece. Does anybody know what I am doing wrong or if there is something wrong with the telescope itself? I'm at my wit's end. Any help would be greatly appreciated.
The field of view through a telescope is usually only a few degrees at best. Often even less than that. I can barely see the entirety of the full moon through one of my telescopes, even with my widest angle eyepiece inserted, and the Moon is only half a degree in diameter.

One of the things you need with any telescope is a smaller 'finder scope' attached to the side. This small scope should have a much larger field of view and, if you have aligned the finder scope with the main scope, should make it much easier to find what you're looking for in the sky. If you have one, make sure to align it with the main scope during the daytime, as it will be nearly impossible to do so at night.
 
  • #5
If I'm not mistaken, I believe he means that when looking through the eye piece only a small amount of area is viewable. Not sure how to put it but when he should be able to see "O" he is only able to see "o" instead with the surrounding area being blacked out. So somewhere there is a misalignment.
 
  • Like
Likes Brian Muller
  • #6
Thanks! The eye piece is in correct. I think it is my eye relief. My eye sight is not what it used to be. My dad can see through it fine. My eye has to be almost touching the lens to see it fill up. Thinking about getting a camera Mount and try that out and put it on my computer screen. In the meantime, I'm going to see if I can see anything on the next clear night. I will get back to you all. It's much appreciated!!!
 
  • #7
Drakkith
Staff Emeritus
Science Advisor
21,105
4,933
My eye has to be almost touching the lens to see it fill up.
That's normal.
 
  • Like
Likes davenn
  • #8
russ_watters
Mentor
20,249
6,842
That's normal.
....and it is common for cheap eyepieces (like what can come with a budget telescope) to have really poor eye relief. you may want to consider buying a replacement.
 

Related Threads on My telescope's field of view is tiny (about a quarter inch through the focuser w/ 25 mm eyepiece)

Replies
5
Views
1K
Replies
4
Views
4K
Replies
9
Views
5K
Replies
2
Views
1K
Replies
8
Views
4K
Replies
4
Views
5K
Replies
18
Views
2K
  • Last Post
Replies
1
Views
2K
Replies
27
Views
3K
Top