Building a Telescope for Physics Class: Choosing Lenses & Mirrors

[Dgolverk]

Hi,
I need to build a telescope for my physics class.
I need to use any 3 lenses(converging or diverging) and 1 mirror.
I was thinking of using an achromatic telescope design for that.
However I am not sure what kind of lenses to use and whether I should make the eyepiece from two lenses or just one.
Should I use 3 converging lenses? 2 for eyepiece then one as an objective lens?
Thank you in advance.

 

[Andy Resnick]

There's several proven telescope and eyepiece designs out there, no need to re-invent something.

Must you only use one mirror? That rules out a lot of designs. Can your mirror be curved? that gives you an extra surface with optical power. Are you free to pick and design the lenses, or must you use lenses pre-chosen? 3 lenses plus one mirror gives 13 variables- each surface shape (7), the spacings (3) and the thicknesses (3). Glass types are another variable, but I suspect you are stuck with BK7 or the like.

I suggest you poke around and see what designs are out there.

 

[Redbelly98]

Also, is something like a Newtonian design allowed? Besides the primary mirror, Newtonians have a second flat mirror whose sole purpose is to redirect the light out to the side. This 2nd mirror has nothing to do with the focusing properties of the telescope, so does this constitute one-too-many mirrors to qualify for this project?