DIY Sunspotter project - heat issues?

[chrisp9au (Chris)]

I noticed an ad for a Keplerian Sunspotter telescope in the IIS classifieds from Hijynx (Benn), price outside my budget I'm afraid.

It occurred to me that my disappointing folded refractor project from last year could be transformed into a sunspotter.
I've got the necessary objective lens, first surface mirrors, and the urge to tinker.

Google searches to determine the light path have turned up diagrams that are confusing my 80 year old brain.
One design has a multi inverted light path, the other is simple but inverted way too close to the objective?

Which of the diagrams below are valid/best, and will there be any issues with heat at any point in the light path?

Your advice would be much appreciated

[iborg (Philip)]

Hi Chris


I think heat is not really an issue, as the light is not focused to a point.


Having said, look at this build. The eyepiece cover is no longer in the best condition.


Good luck.


Philip