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Mirror 610 F3 meniscus

May 8, 2026Massimo MarconiConstructive Reportmeniscus, parabolic mirror, sub diameter

The manufacturing phases of a meniscus parabolic mirror 610 mm in diameter and 20 mm thick, focus 1770 mm with focal ratio of F3.

Rotating table for meniscus mirrors

Nov 19, 2023Massimo MarconiEnvironment and toolsmeniscus, rotating floor, parabolic mirror

A simple rotary table for working mirrors, homemade with some carpentry tools…

Building a Ritchey-Chretien: preconditions

Jul 18, 2017Massimo Marconi1 CommentConstructive Report

And, it's possible to do it (*) by manually working the optics and you don't need special equipment or more sophisticated than what we normally use for the construction of a parabolic mirror but, let us now, to embark on such an adventure necessarily have to have more than one working behind, to understand how to generate two hyperbolic surfaces, and

How to read the fringes of Newton and correct the convex mirror.

Dec 5, 2016Massimo MarconiSecondary mirrorNewton's fringes, sub diameter

As we have seen in this article, a convex secondary mirror can not be tested directly in general (*) . One of the methods is used to refer to a concave mirror which has the same shape of the surface that we want to get on the convex mirror. By overlaying the two mirrors, the analysis of the interference fringes by means of

How to build focal lenght and mirror's depth.

Aug 17, 2016Massimo Marconi2 CommentsRoughing and grinding

One of the aspects that usually remain unclear, during the design phase of a mirror roughing is what must “to dig” to reach the focal length of the project, before moving on to the next abrasive granulometry. Who has a fair number of self-built mirrors, now it possesses the experience is the ability to assess whether it is digging

how to parabolize a low focal ratio mirror ( F2-F4 ) - Part Three

Nov 19, 2015Massimo Marconi2 CommentsParabolizzazioneparabolic mirror, sub diameter

Now let's see how to develop a procedure that takes account of the problems highlighted in the article II, that is how to generate the project by means of a parabola working as regular as possible, with particular attention to the control of the figure during the intermediate stages of processing. THE METHOD “CUSTOM” The name only want to indicate they are not

how to parabolize a low focal ratio mirror ( F2-F4 ) - second part

Sep 26, 2015Massimo MarconiParabolizzazioneparabolic mirror, sub diameter

Is’ useful at this point, a recall on processing techniques with the tools at the sub-diameter, in particular how it is possible to increase the curvature of one or more zones. Then resume the concept according to which through sub-diameter strokes , External areas increase their curvature while those inside the decrease,

how to parabolize a low focal ratio mirror ( F2-F4 ) – first part

Aug 24, 2015Massimo MarconiParabolizzazionecaustic, parabolic mirror, sub diameter

STARTING BALL AND FINAL PARABOLA the reflection of light emanating from infinity on a spherical surface does not generate, as it is known, a single focus point, but rather a figure that “caustic reflection” which identifies the rotation surface where they concentrate the reflections of a point source . As you can be seen in Figure

Curvature Correction with Sub-diameter

Apr 4, 2015Massimo Marconi13 CommentsCorrection of defectsparabolic mirror, sub diameter

We saw in a previous article the general operation of the racing technique with sub-diameter. On that occasion, we examined the aspect relating to processing by identifying the zones or circular sectors in which the material removal takes place more or less effectively. Let us now go into more detail about the effects that this process produces

Iron oxide “Rouge”

March 17, 2015Massimo Marconi3 CommentsMaterials and abrasiveabrasive, cerium oxide, iron oxide

Is’ was one of the first polishing abrasive used by opticians , its properties make it still one of the best polishing agents ,but some contraindications have decreed the abandonment in favor of other products , luck in the iron oxide optical processing is finished with his fame at the beginning of chemical production