Making a modifier disk

[Mr.Spradlin]

So I was reading about the modifier disk that comes with March scopes and figured I would attempt to make one for a Weaver T36 using a factory lens cover. I figure by putting a certain size hole in the center and tapering the edges along with coating it in a non-reflective flat black coating it should work.
Now the question I have. What size hole would be a good place to start at?

Thanks
Matt

 

[JimPag]

Well Matt. The outside dimension for a March Disc is 60 MM. The hole in the middle of it is 35MM wide.

 

[Mr.Spradlin]

Well Matt. The outside dimension for a March Disc is 60 MM. The hole in the middle of it is 35MM wide.

So in theory a hole about 23mm should act the same if the quallity of the lenses are the same correct?

 

[JimPag]

So in theory a hole about 23mm should act the same if the quallity of the lenses are the same correct?

I know that a Weaver T36 has a 36mm piece of glass, but I don't know what the objective opening is. Christ I just sold my 8th one and never measured the obj opening.

 

[jlow]

The information you need is here:

http://marchscopes.com/faq.html

 

[Mr.Spradlin]

Well I am starting out with a smaller hole then I think I need. Figured it is easier to enlarge a hole then try to make it smaller.

 

[JimPag]

Well I am starting out with a smaller hole then I think I need. Figured it is easier to enlarge a hole then try to make it smaller.

Yup a little too small.

 

[fotohunt]

What is the purpose of a modifier disk? Never mind, just read about it