The Charlie Bates Solar Astronomy Project is proudly sponsored by the following fine companies:
Transit of Mercury in the Spicule Layer. Phil took this great image with his Quantum 6 Scope, Solar Spectrum etalon and PGR Camera.

Welcome to Solar Chat! The best forum for Solar Astronomy
Moving forward from solar cycle 24 to 25


Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Post Reply
The Sun?
The Sun?
Posts: 5
Joined: Tue Mar 28, 2017 4:24 am


Post by grdc65 » Sun Apr 30, 2017 2:00 am

Hi all,I have a lunt 50 which I would like to mate to a 90mm 660mm focal lenght refractor.
This is the first time I am thinking of trying this modification,so there are a couple of questions I would like to ask.
1.would the resulting scope still have a 90mm effective aperture,since both the lunt and the 90mm
refractor have a F7 ratio?
2.How do I determine the exact placement of the lunt adaptor in the 90mm scope body to achieve focus?
3.What materials can I use to make the adaptor that will fit the lunt to the 90mm scope?
4.After removing the Lunt 50mm objective lens from the the scope,would I need to remove the remaining white telescope tube that is left over and attached to the etalon assembly?
I will also use a lunt 75mm ERF just behind the 90mm objective lens.
Any other general advice related to the scope mod would also be great,thanks Nick.

Post Reply