50 mm achromatic doublet refractor telescope, DIY do it yourself, ATM amateur telescope making.

 

THINGS REQUIRED:

1. 50mm diameter pvc pipe of 54 cms length, Quantity one. 

(to hold the telescope and eliminate )

2. 50mm pvc coupler, Quantity one. 

(to hold the objective lens/main lens in its place)

3. 50mm to 32mm pvc reducer, Quantity one. 

(to attach 50mm tube to eyepiece tube)

4. 50mm Achromatic lens 

(Primary objective lens)

5. 25mm kellner design eyepiece and 10mm plossl design eyepiece.

(formula for magnification is focal length of Objective divided by focal length of eyepiece

25mm kellner eyepiece clubbed to telescope=700/25=28X,

10mm plossl eyepiece clubbed to telescope=700/10=70X)

Note: 

• Use achromatic objective and nothing less than kellner/plossl eyepiece design, so that there is least chromatic aberration in your observation.
• Maximum useful magnification for any given telescope is two times the size of its aperture, hence 2 X 50 = 100X any trial of achieving more magnification will produce blurred images.

PROCEDURE:

On completion, this is what your OTA optical tube assembly will look like.

• Insert achromatic lens 50mm given inside coupler such that you have inserted concave part.
• Now insert a 50mm pipe into the coupler. So that your lens will not fall off on reversing the ota.
• Roll a small piece of paper in the focuser's black part opening and insert the focuser hard into the reducer. 
• This reducer is to be inserted into the pipe now. Walla your telescope is made now. 
• Just roll a single layer of double duct tape in both the eyepiece and insert it into the focuser.
• Start observation with a 25mm eyepiece watching the landscape, than the moon and so on. Learn about focusing and you are good to go to begin your journey of astronomy learning.

You can also buy achromatic lens and Eyepiece from the below link:

https://sites.google.com/view/india-astronomy-club-iac/shoppping/optics