While I have built and used an interfrometer and still have the equipment to do so, I don't do any testing with that tester. I'm running the SDAA mirror making...
Just reviewed my messages on today which is sun a.m.. I will try and make the next class if it is still there and I don't have to work on that day. Hope you ...
I've been running the class for about 3 years now as the local guru. We've just moved from the UCSM campus as they want to charge for parking on weekends and...
Ok I performed the required star test. After finding a nice bright star I put in my 7.5mm EP. After racking it outside of focus I found the following. There...
... Try comparing inside of focus also. The disk of light with black shadow should look similar to what you describe as outside of focus. The oval black...
Mel, I forgot to type the results, but I did that as well. The results are similar, but not identical. When inside of focus the bands look similar and are in...
So, where is the class going to be? In case I ever get your to 11" blanks done. Visit my web page for an ugly new photo. . . . Richard ... From: "Bob May"...
... Ok, this description makes it sound like your optics are pretty good. And it sounds like by remounting the mirror you've improved the image. In order of...
... good. And ... Thanks for your help Mel, and others. I'm going to try to post some pictures of the scope for all of you. I'll certainly buy the top 3 on...
What's going on here? I thought we had this list set so that the first message from a new member had to be approved by a moderator? I am a moderator, and now...
In case you haven't noticed, you are dealing with Yahoo. They, of course, are a bunch of Yahoos there and have probably done something to the settings as part...
Bob May wrote ... The big thing that you should consider is whether the camera allows for the swapping out of the lenses. It does no good to buy an otherwise...
That is a bit of work to get an image but it does indeed work. Once you build a block that sits behind the tester with the telescope and the camera on it, you...
I've been doing more searching and found more info on subsurface damage from grinding. See: http://www.attawaygems.com/NMFG/cabinet_makers_and_chain_saws.html ...
Does anyone have a copy of Lapidary Journal, Feb 99? See: http://www.lapidaryjournal.com/archive/299toc.cfm Specifically I'm looking for the article on page...
Disclaimer, I'm not sure where the boundary is for "very thin" glass comes in, nor have I polished one. Wouldn't a flash polish on the back be just as...
... and later ... Possibly the depth in gems is larger because the crystal lattice propagates the fracture more easily than glass would. Think of cleaving...
The deadline has been extened until the end of the weekend so we can have the needed time to add our imput. here are the details. Greetings, my name is Melissa...
Hi, I'm trying to sort out whether a mirror is astigmatic, or its cell is pinching it, or both. When I startest, I get an inconsistent change in the shape of...
Does anybody know of any translations into English of two books by Dmitry Maksutov? The two titles I have in mind are: Astronomical Optics (second edition,...
you can rule out pinching by making sure the retaining clips are not over tight. The weight of the clip its self is enough to hold the mirror and loose enough...
John, Thanks for the reply. The mirror clips are fine, lots of clearance, and there is nothing binding in the cell. The image does sort of rotate but it is...
Dave, I had a bad feeling it would not be that simple, especially with what may well be a different than usual astigmatism. Thanks, Rod ... show ... the ... on...
It sounds like the mirror cell may be the problem. Tell me a little more about you, mirror size, thickness, and describe the cell its-self. John kagey John, ...
Subsurface damage happens when Blanchard grinding and that ends up changing things a bit with a piece of glass. FWIW, Twyman Effect deals mostly with the...
