Collimating 4.5" Reflector

[Diego]

Hello,

Im seeking advice regarding how to collimate a telescope. Its 4.5" reflector. Every tutorial video i have watched involving collimation used the laser collimator which i dont have :/ Is there a way to do it manually? If there is, is it something a telescope rookie like myself can accomplish?

Thanks

[sixela]

Yes.

Is the mirror (accurately, one might hope) centre spotted?

What kind of 4.5" reflector is it? Long, short, short but with a lens group in the focuser to extend the effective focal length?

Did you get a collimation cap with the scope?

[Astro_Baby]

You could do a 4.5" scope with just a collimation cap. What kind of scope is it ? Make, Model etc

[Diego]

Ill get those exact details soon since it is my cousins old one... from the top of my head the small label on the scope said: its a tasco, 114mm aperature, and 500mm focal length, and then it says something about "coated optics"... im not sure on its exact model number of the top of my head and my cousin wont answer the phone

is the collimation cap something id have to purchase on the side or something it would come with?

Side Note: This telescope is from like 1996 and has been barely used in the whoel time :/

[Astro_Baby]

Okies - thats enough info - its a 114mm apertire with a focal length of 500m that makes it a focal ration of F4.3

You could collimate such a small scvope with a collicap - you can buy these cheap enough or make one. Its just a cap that fits into the focuser tube with a hole in the dead centre.

If the scope has 1.25" eyepieces you can use an old 35mm film cannister for this but the scope may have older .965 eyepieces - not sure what you could make up if thats the case.

[Diego]

thanks for the help

is a collimation cap something that specialty shops would only have, or can i buy one at department store or something?

[Astro_Baby]

Well before you buy one you need to establish if its a .965 sized focuser or a 1.25" JUst measure across the focuser tube or one of the eyepiueces - is its less than an inch ita .965 if it bigger its a 1.25"

You can but collicaps from any astronomy outlet pretty much - you wont find them outside of the astro world.

As I say though you can make one if its a 1.25" focuser.

[Diego]

Im gonna go see if there any youtube vids on making a homemade collicap

Thanks for the insight

[sixela]

If the scope has 1.25" eyepieces you can use an old 35mm film cannister for this but the scope may have older .965 eyepieces

If it's a .965 focuser, it sometimes has a holder at the end you can unscrew, and some film cannister lids actually fit very nicely over the 0.965" drawtube and can be used as a base for a collimation cap.

[Diego]

thanks for the tip