| Rodney Daigle's Amateur Telescope Making Pages |
| The first telescope I made is a 6in f5.3 dobsonian. I will place Foucault, Ronchi, and star testing pictures of the optics in the process of being figured or parabolized, i.e. the task of polishing the profile of the final "figure" or collective shape of the reflecting portion of the mirror. |
 |
 |
| Here is a Ronchi simulation picture of an ideal 6in f5.3, the six shots show what the ronchi lines should look like at predetermined distances from the tester. They run from .1in inside focus to .7in outside focus. The FREE program used to generate this image was developed and is available from Mel Bartels website, the url is...... < http://www.efn.org/~mbartels > |
| Below is a composite pic of actual images of the 6in f5.3 mirror folowing the same distance scheme of the ideal images. As you can see all images are a fairly close match hence the name of the program "The Matching Ronchi" . The pictures indicate the mirror wavefront is overall smooth but with a slight tde (turned down edge). I decided with Mel's advice to take Foucault readings which is a process that applies numbers to zones of increasing diameter to obtain an extremely accurate graph of the mirrors polished surface. |