Back to Home

ATM Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Amateur Telescope Making | Post

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
6" F/5 Primary Questions:

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Mark Windham on October 8, 2002 16:37:59 UTC

Hi! I have a 6" f/5 primary mirror and am just about to start buying the rest of my scope components and would like to avoid any major mistakes... From what I can gather, a 6" f/5 would normally be paired with something in the range of a 1.6" secondary... however, I know that there are MANY variables in the equation and your advice would be greatly appreciated. I've heard that 17% light blockage from the secondary mirror is optimal (not sure where I heard that), is there a method of determining the blocked light percentage?
If possible, I would appreciate some basic recommendations for all of the general components such as 2nd mirror size, focuser size/height and distance from secondary, tube size, recommended eyepieces and so on. This is my first project (a cheapie) and I hope that, upon completion, I'll be ready to build what I really want: A 10" Dob... (Nothing against the 6" f/5, it should be great for wide field views).

Thanks again!

Here are all the specs I have on my 6":
Coating = al+sio
Clear aperture 6inches = 152mm
Focal length 29.38inches = 746mm
Focal ratio f/5
Mirror thickness 0.625inches = 15.9mm
Thickness/diameter ratio 1:9.6

FYI: I've tried using NEWT but can't seem to figure out the recommended secondary mirror size.

Follow Ups:

    Login to Post
    Additional Information
    About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
    Unless otherwise specified, web site content Copyright 1994-2024 John Huggins All Rights Reserved
    Forum posts are Copyright their authors as specified in the heading above the post.
    "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
    are trademarks of John Huggins