Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

Novice wants telescope recommendation


Recommended Posts

I have a 20+ yo Celestron C90 & I know nothing about any technical details about scopes or optics.
An osprey nest is about 1 mile from my house with clear direct line of sight to it.
The nest sits atop a 25ft utility pole that is only a few feet above sea level.
My house is on a hill at about 100ft above sea level & has a slight downwards view of the nest.
I want a new telescope that will present the nest about 4+ times larger than my C90.
What are some recommendations?

Link to comment
Share on other sites

1 hour ago, SolBeach said:

I have a 20+ yo Celestron C90 & I know nothing about any technical details about scopes or optics.
An osprey nest is about 1 mile from my house with clear direct line of sight to it.
The nest sits atop a 25ft utility pole that is only a few feet above sea level.
My house is on a hill at about 100ft above sea level & has a slight downwards view of the nest.
I want a new telescope that will present the nest about 4+ times larger than my C90.
What are some recommendations?

If you still have just the standard 32mm eyepiece that came with the telescope then you will be getting a 39x magnification. You could improve that by getting a smaller focal length eyepiece as @scotty38 and @Bluemoonjim have suggested. You could buy fixed focal lengths or try a zoom lens such as this one from Svbony which would give you a magnification range of 41x to 125x. You might start to see a lot of heat haze at the higher magnifications though that means although you are seeing a larger image, it may be less satisfactory than expected.

The calculations above are assuming you have the 'newer' version of the telescope with a focal length of 1250mm (this should be recorded on the scope somewhere). Previously the focal length was 1000mm until the late 90's - if you have this version the magnifications will be slightly lower.

Link to comment
Share on other sites

I want to THANK all who replied. Again if I knew what I was doing I would not be posting here.

I have the older 1000mm model which rotates the whole barrel to focus and it came with 26mm eyepiece

If I were to get a 4mm eyepiece, about how much total or additional magnification would I see?

Link to comment
Share on other sites

1000mm divided by 4mm = 250x magnification. The 26mm eyepiece will be giving 38x. 250x might be too much magnification, depending on the conditions you observe under.

For the sort of purposes that you want to use the scope for you might want to consider a zoom eyepiece. A 21.5mm - 7.2mm zoom eyepiece (for example) gives you magnifications between 47x and 139x so a good wide range covering a 1:3 ratio.

 

 

 

  • Like 1
Link to comment
Share on other sites

I agree with John, a zoom eyepiece for terrestrial viewing is probably a better way to go than a 4mm eyepiece. Chances are that at 250x magnification, most of the time, air disturbance will degrade the image too much. At least with the zoom you can 'back off' the higher magnification until best image is achieved and push it up if conditions allow.

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.