Creating a solar dob from a standard one query

[bomberbaz]

Sorry for title but for life of me I cannot think of anything more suitable.

I have a 14" dob. Thinking of stopping it down from a 14 to create a 5 inch solar white light scope. 

Measured the area around secondary and space is ample for a 127mm. 

Best solar filter advice please, I was considering thousand oak!

Also currently F4.8. Again not sure if this maths is right but 14/5=2.8.

F4.8x2.8=F13.44

Have I got this wrong or missed anything?

Cheers for any reples.

Steve 

[Stu]

Presumably you are going to make it so it just fits between secondary vanes? That will give you an unobstructed scope which would be good.

You basically want to make a full aperture disc to cover the front, with the sub aperture hole cut out. Might be worth blackening it to cut reflections.

I would use Baader AstroSolar film, the ND5.0 Visual stuff. It’s cheap but excellent quality. Obviously make sure it is held in place firmly. You could sandwich it between two bits of ply to be sure, and obviously make sure it is firmly attached.

If yours is a truss dob, then make sure it has a shroud fitted, otherwise you might end up setting fire to things! 😱

[Stu]

Just found this post/thread from @Moonshane (tagged in a desperate attempt to lure him back to SGL, miss you on here Sir!). This was for night time astro with a 16” dob but the principle is similar, just with astrosolar film covering the hole.