Hello

I am building a long focus 14 inch "planetary" scope similar to the
design seen here at this website:


Homebuilt big telescope

It will be F/7 or F/8. With a long focus scope can I use simple (ie
Huygens) eyepiece designs? I would like to make the eyepieces
myself.

Thanks
Dom

A Huygen eyepiece is not recommended for f/ratios below f/8. At f/15 this primitive design actually performs fairly well.

You might want to try your hand at a better design:

http://home.fuse.net/astronomy/eyepieces.html

http://www.astronomyboy.com/eyepieces/

Dave Mitsky

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