March 2007

Preliminary study for my 14" f/5 scope: The Mirror Cell - summary of PLOP simulations (1)

This page summarizes the results of a first preliminary study for finding an appropriate cell design for my primary mirror. These studies would noat have been possible without the assistance of PLOP, a free simulation tool for computing mirror deformations by means of finite elements analysis.

The cell designs included in this first study are a mix of readily available designs and other designs I created (either they were described but without a PLOP input file, or they were not described at all).

My 14" f/5 ultra portable dobson telescope project

At last I decided to give the 14" f/5 optics I bought more than 10 years ago a real life: I'll be building an ultraportable dobsonian telescope.

I start with the following parts list which I already have acquired over the years:

Choosing eyepieces


This page provides some assistance in selecting your eyepieces.


  • For a "complete" set of formulas and definitions, check the ATM telescope formulas page on this site.
  • Definitions
    • Aperture: opening of the telescope (diameter of the objective). SYMBOL: D
    • Focal length of the primary: SYMBOL F
    • f-number: SYMBOL: f/ = F / D

Message from Anthony J. Cook re: Serrurier Truss

Date: Thu, 11 Mar 1999 23:31:29 -0800
From: Anthony J. Cook
To: Olivier Biot
Subject: Serrurier Truss


Common Telescope Formulas


This page is an attempt to gather most of the formulas used with telescopes. I do not grant that all formulas here are correct, but I've been using most of them when building my own scope. Please always use the same units. I prefer working with millimeters. Some formulas are only applicable when one parameter is given in a certain unit that is then written next to the dimension, between square brackets, as in : D[mm].

General formulas

  • Definitions

International Dictionary of Terms in Amateur Telescope Making

Currently 9 languages are supported: English (of course), French, German, Dutch, Portuguese, Spanish, Indonesian, Italian, Russian.

All words are given in English, then they are explained in English, and the translations follow.


Probably my very first scientific interest. The astronomy bug hit me when I was around 6 years old. Over the years this hobby has been more or less present in my life, with a recent boost since 2004.

Astronomy Gear Pages

The following pages provide information on setting up astronomy gear.