Cassiopeia Observatory logo
Last updated: 14 October 2010
This page is for user comments and information specific to the Meade DS, DSX, and some older telescope models. Accessories and Feedback items appropriate to the ETX models are posted on other pages as appropriate. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me for posting. Please use an appropriate Subject Line on your message per the Site Email Etiquette. Thanks. Remember, tips described on this site may invalidate the warranty on your telescope or accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	re: parabolic mirror on a meade ds-114
Sent:	Monday, October 11, 2010 19:29:57
From:	richard seymour (
You can fairly easily -bend- the DS-114 mirror into a parabolic shape.

In short, you glue a bolt to the back of the mirror (which gives you a
threaded "handle"), and then rig something to allow you to "pull" on the
bolt with a nut. Very little flexing is required.  The focal length
changes very little.

Here are three Sky & Telescope articles describing the procedure (with

Nov 2000, p 131, Alan Alder  "Flexing Spheres into High-Quality
Telescope Mirrors"

Feb 2001  "Flexing to Parabolize a Mirror"  by Thomas Dobbins

Nov 2003, p 138, "An Inexpensive Microflexed Newtonian Reflector" by
Ernie Pfannenschmidt

have fun

Subject:	parabolic mirror on a meade ds-114
Sent:	Saturday, October 9, 2010 09:42:45
From:	Maria Romo (
I'm new to this hobby and am completely hooked. I know your time is
limited so I'll be brief. My question is about the primary mirror on the
meade ds-114EC. I was thinking about purchasing a parabolic primary to
replace the spherical. I have already upgraded the eyepieces. Would this
benefit this scope or am I wasting my time with this? I am aware that
this is an entry level scope and would appreciate your knowledge in this
matter. Also, would I have to change the secondary mirror if I was to
change the primary? In a nutshell, is this scope set up for a mirror
upgrade without doing a complete overhaul?
Jason Goss & Maria Romo
Mike here: Swapping the primary mirror with a mirror of a different optical design and focal length will require more than just replacing the mirror. You will have to change the secondary mirror and likely its position as well to match the new mirror. Then you will need to re-collimate the telescope.


Thank you for replying. So it is possible then. The focal length part
has me a little confused though. Are there more powerful mirrors than
what comes standard on the ds 114? (parabolic) And will they collect
more light?
Mike here: Anything is possible. You may just have to cut new holes in the telescope tube, make your own mirror attachments, or perhaps even shorten or lengthen the telescope tube. Possibly lots of work. Have fun. A curved mirror focuses light at a certain distance from the mirror's surface. That's the focal length. How long that focal length is depends on the design of the mirror. It could be 400mm to several thousand millimeters. The eyepiece of the telescope then magnifies the focused image from the mirror, so the eyepiece has to be at the right distance. Larger mirrors will collect more light than smaller mirrors. The DS models come in different sizes. In fact, many telescope models come in difference sizes. Check the various telescope manufacturers web pages for more on their telescopes.


Thank you for the info. I think I understand the focal length now. If I
got a mirror with a 400mm focal length I would have to shorten my tube
being its set up now for 910mm(right?) I think that I'll just leave the
existing mirror in there and start saving for an intermediate scope in
the future. I would hate to ruin my first scope! Thanks again for your
help, I believe you just saved me a lot of headaches!
Mike here: Yep, the 400mm focal length mirror would have its focal plane well inside the telescope tube. Good decision to not try to swap the mirror.

Feedback Archive

Check the Feedback Archive for previous editions of the DS, DSX, and Older Models Feedback pages.

Go to the ETX Home Page.

Copyright © 2010 Michael L. Weasner /
Submittals Copyright © 2010 by the Submitter