Articles

Thermal deformation
Explores various models that estimate the transient temperature gradients inside a telescope mirror, specifically during the cooldown phase prior to the actual use.
Cell-induced deformation
Analysis of the effect of the torque issued by flotation cell elements that are glued to the mirror. In moste cases other than 3-point cells this leads to unacceptable deformation.
Bath interferometry
An introduction to the background, construction and use of a Bath interferometer.
While the Foucault test fails to give objective results, Bath interferometry sets the new standard for amateur mirror makers. Thorough evaluation of Foucault test consistency is given in this article by Jan van Gastel.
Schiefspiegler toolkit
A summary of the treaty on two-mirror Tilted Component Telescopes by Anton Kutter. This is presented in the form of a design guideline, used to estimate the dimensions and characteristics of a target system. The results can then be optimized with ray-tracing software.
A reformatted and corrected version of the original article can be found here.
Focal plane illumination
An excercise to calculate the combined vignetting of secondary mirror and front aperture.
Een Planetenkijker
Powerpoint presentatie met overwegingen voor een planetenkijker gebaseerd op een 200mm F/7 parabolische spiegel.
A telescope primer
This is an old article, residue of my thinking about my first telescope design..