WHY’ STUDY WHAT MANY SOFTWARES OFFERS’ READY TO USE The study of the Foucault test results is very important in order to be able to evaluate the advice provided by the software prepared for this calculation independently and well. Nobody is perfect and even programs for these calculations are, while he is able to guide
As described in the previous article entitled "Preparatory phase to Foucault's test", We have prepared the room, with mirror aligned and testers on their tables and stands, left to acclimatize the mirror to reach the safe thermal equilibrium with the ambient temperature, and now we are ready to begin the first test session. take the
NOTE for those who are going to read this article already having previously read the two articles 1) “FOUCAULT TEST; what is it and how to function” e 2) “Setup del test in Foucault”, it will be interesting to find an answer to the question that arises spontaneously, which is: “But when the test should begin to perform
The TEST AMATORIALI The need to perform the tests on the optical processing in, typically with parabolic reflective surface for Newtonian telescopes, It is designed to be able to see them with the presence of any of the relevant mirror surface shape errors, and of these errors get the QUANTITY ', in order to study and apply
For those looking for ideas to gear up realizing what it takes to lead the Foucault test, I present a gallery of images of my way to work. The environment must be a room with the temperature as constant as possible, and a length of at least a meter and a half more than twice the focal length
As regards the control of the optical mirror, simplest and most widely used tests, especially at the amateur level, It is definitely the Ronchi Test. This test uses a beam of light is transmitted and then reflected from the primary mirror, which is passed through a reticle with a series of low-frequency
When you run the Ronchi test, often there is found to have to do with the figures of the shadow lines that may be different from those that are usually presented to explain the most common defects in optical processing. Here you need a general method that can explain the behavior of any line
The WHAT, the reason why', the WHEN and HOW: Let's start from WHAT: The Couder mask is a technical tool of cardboard, or other stiff and Matt material, that prepended to the parabolic mirror in construction to perform on it the Foucault test, It serves to measure the radius of curvature Rdc of the various annuli
A Foucault Tester, with fixed light source fixing to be carried out with devices which commonly have at home (webcam and a pen / USB stick ) screwdriver , hacksaw and simple components purchased from Brico with little expense. below of the components you found the exploded, assembly instructions, list of materials and some support attachments.
Ronchi pattern
One of the tools needed to run the Ronchi test is the namesake grating. This is a series of opaque parallel lines spaced equally so you have a spatial frequency that can go from 4 all 8 per millimeter. A pattern with a lower frequency can be used if it is necessary to test
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