Telescope mirror testing software

The software can instantly delivers wavefront analysis, so that the telescope can be. Telescope mirror testing posted in atm, optics and diy forum. Browse an extensive selection of astronomy equipment at. What is less straightforward is the way of testing. The star test is very critical and can show even slight aberrations. Parabolizing a telescope mirror mel bartels and bbastrodesigns. Telescope makers can use a variety of techniques, but ordinary telescope users find that learning a workshop method is difficult.

The use of these sensitive tools require isolationflotations tables and high quality. Testing a star off center, or testing a scope not accurately aligned collimated or testing a scope that has not cooled to the night time air temperature can produce spurious results. A better way of showing how accurate a telescope mirror is by strehl. Stellafane amateur telescope mirror making foucault data reduction software. Star testing a telescope can be a great way to determine if any errors are present in the optical system and what those errors are.

When this is determined, you can decided which zones to work on, or declare the mirror. The ronchi test for telescope mirrors is perhaps one of the easiest optical tests to learn and use. This is a test that measures the mirrors surface using optical path differences. Measuring telescopes and refractors optical performance with a flat mirror testbench tests.

It allows you to easily and quickly change any of the design parameters of the telescope. Before you begin star testing, make sure the telescope has cooled down to the ambient. Also, a wave front test is only testing one part of the mirror, so it is an average. Star testing astronomical telescopes, a manual for optical. Four lessons in mirror testing lockwood custom optics. A mirror becomes more parabolized while its cooling, so it will look more parabolized at first than it really is. This video shows how to use an iphone to make a foucault telescope primary mirror test. Ronchi for windows is a simulation program for amateur telescope makers atms. The only software design tool you will ever need to design, build and test a telescope that is truly. The interferograms are then processed through a appropriate software. The f number is a ratio between the focal length and the diameter of the primary mirror.

There is the current altazinitiative where telescope. Interferometry for amateur telescope makers by william zmek. Cheap interferometer for optical testing of telescope mirrors things required xyaxis stage plywood board of one square feet. Remember that the star test is a complete test that includes optics and telescope.

While we cannot use it for testing the completed mirror, we need it to control the process of. Unlike sphere blue, where normal to the surface at any zonal height leads to the same point the center of curvature thus every zone focuses pointobject placed at the center of curvature back onto itself, paraboloid red flattens out toward the edge, with the surface normals, coinciding with local, or zonal radius of curvature defined as a radius of the osculating circle for. The shaping and testing of two 20 optical telescope mirrors. Mirror testing is one of those vast fields where the more you learn. It is a telescope design software of the most popular telescope systems used by. However, the price of the mirror increases as the mirror gets larger. Our telescope mirror coating process utilizes the latest methods in optical coating technology, perfectly suited for the often harsh environment of the telescope mirror industry. A 10inch telescope mirror has a 10inch or 250mm primary mirror. Use the program plop to optimize the back support for the mirror pointing to the zenith use this mirror edge support calculator to analyze the edge support for the mirror. These tests are quite practical for an enthusiastic amateur making hisher own mirror and telescope.

For primary mirror testing, our optical shop incorporates the use of two interferometers, an equalpath and a scatterplate. To run an analysis, all that is needed are the inside and outside of focus spot pattern images and the telescope s f number. A mirror mount is needed to hold the mirror during testing. They would use some of the most advanced interferometers in the world to measure the mirror, and subtract the spherical aberration to do a software null of the mirror. The free version of k3ccdtools software helps you do this. Telescope making is at the heart of the springfield telescope makers after all it is two thirds of our clubs name and on these pages we hope to show you that you too can make your own telescope and it can be an excellent performer. The manufacturing and testing of a mirror is a process distinctly different from the final testing and verification of an optical surface. After you take foucault test measurements, you need to process, or reduce, the data, to understand the shape of your mirror surface. The lyot phase contrast test reveals very small scale surface roughness. The strehl percentage indicates the amount of light which is returned by the mirror, within the central peak of the airy disk. Browns all about telescopes to malacaras optical shop testing. Rick blakley for his patience in testing my software. A laser pointer with the lens system removed is perfectly. Mirror manufacturers need to have a dedicated test tunnel.

Both of the twin 20 quartz telescope mirrors are finished. Ray traces and other analyses are performed very quickly, and wavefront plots and similar results can be plotted, saved to file, or stored as image bitmaps. Testing a telescope under the stars is a critical examination. If your telescope seems to fail, do not immediately confront the dealer or manufacturer. Testing and refiguring services are also available. If you are approaching optical testing from a newbie standpoint in order to test your own mirrors as the op is doing, there is no way and i say this. Modas stands for modern optical design and analysis software it is a telescope design software of the most popular telescope systems used by the amateur astronomers and telescope makers, including spot diagrams, ray fans, wave aberrations, diffraction analysis, optical layout, optimization, tolerancing, mirror testing. It ray traces the telescope checking for vignetting, optimizes diagonal size, calculates baffle size and position and more. Laser pointer camera lens filters coated one side flat mirror test mirror. In addition to directly looking at the star image, star testing telescope optical quality can be conducted by using a straight edge cutting into the focus of the objective. My own testing, star testing, and highpower observing using mirrors that i have.

Useful software tools are available to assist with the analysis of the test optic. The products made by 4d are used in the university of arizona mirror lab to test 8meter and other large mirrors with very sophisticated metrology. If you are building a telescope or if you want to see if a telescope primary mirror has a good figure before you buy it, you need to perform an optical test of the mirror. Gordon puts the a disk on the test stand and shows how the foucault test and the ronchi test look. Discussion approach to mirror cell design to design a mirror cell that will make your mirror perform at its very best, follow this procedure. The testing of astronomical telescope mirrors page 6 optical layout for the autocollimation test in fact the flat reference mirror does not have to be perfectly flat it can be slightly convex or concave but it. Modas optical design program software overview my optics. Invented by the french scientist leon foucault in 1858, this ingenious test uses point source of light placed at the center of curvature of a concave mirror in practice, slightly to the side, so that the mirror. This will be a space set aside in the factory which is long enough to test mirrors and can be maintained at a very even. For a test of your mirror, please send it properly wrapped and packed and insured with returned postage included. I am looking for any method or instrument to test the curvature of the mirror. Many telescopes, even beginner models, ship with software to help aim the telescope.

This is a very modest mirror by todays standards when 20 inch 0. Geometry of the foucault test in determining how close is mirror surface to that of a paraboloid. Optical data can be imported from and exported to various file formats. Telescope mirror testing atm, optics and diy forum. It simulates the appearance of a mirror while undergoing the ronchi test. Put in a highpower eyepiece about 25x per inch of mirror diameter and see what the image looks like. To close out the book, i offer some words on how to fold the rating of the objective mirror into a more complete perspective on the performance of a finished telescope. Back in the warmth of the shop autocollimation testing having the telescope and good mirror cells for two large mirrors available to me, i had a golden opportunity to test the 28 mirror and an old 32 mirror in the telescope.

Like all observing, proficiency at star testing takes time. If you are building a telescope or if you want to see if a telescope primary mirror has a good figure before you buy it, you. I am grinding an 8 inch f6 telescope primary mirror. Atmos is a powerful program for telescope analysis and design. Unlike the more common foucault test, the beginner will have very little trouble seeing something the very first time they try the ronchi test on their mirror. A tripod is a threelegged support device for the telescope. Mirror mask if youre testing a mirror, reducing its aperture by placing a circular ring of card about 5mm wide over the end of the scope will help you detect the presence of an optical fault known as a turneddown edge. Today, we have unprecedented access to information and software like. To test that the telescope will give a pleasing high power view of stars and resolve to its theoretical resolution limit, in other words, that diffraction effects dominate the image, use an eyepiece equal to the focal ratio of the telescope, e. The freeware version is limited to just four optical surfaces.

I have built and worked on many telescopes, mirror cells, secondary holders, and. Stellafane amateur telescope mirror making foucault data reduction software foucault data reduction software after you take foucault test measurements, you need to process, or reduce, the data, to understand the shape of your mirror surface. The mirror cell is held in alignment in the telescope by a hexapod positioning system that can move and tilt the secondary mirror in all degrees of freedom. If you seek more features, you could also purchase software separate from what accompanies the telescope. The santa barbara instrumentation group sbig created the hartmann test software that is currently commercially available. Optical testing is a big topic with a lot of facets. Rating a mirror by adjacent rms is saying that the mirror has but broad smooth gentle errors, and admitting that it will be used at the bottom of the ocean of air. The tertiary mirror is a large flat mirror, located in the center of the primary mirror, that is used to direct the telescope. A spherometer is a very important tool during the process of grinding a mirror.