... previous mask ... of ... isn't the ... Yes, I guess the math proves there's not enought error to cause the differences in the tests. I had one question...
Hi, I'm working out the design of my next big Dob and I wanted to get some feedback about an idea to have the Alt drive and encoder feedback friction fed. The...
If you are going to drive the encoder from a roller, it MUST be the one that drives the scope. Otherwise, you only know that the encoder roller moved so far......
... I don't know anything about the math behind FigureXP or what the % correction values actually mean. I hope someone else on the group can shed some light on...
James, Since I had been working a 1" thin glass blank I was planning on using a cell with many supports. Since the 18" is NOT thin would a 9 point cell suffice...
John, ... I will take a stab at this. As I understand it, the % zonal correction is a measurement of how the slopes are changing between zones. A perfect...
Perhaps this is the source of what ... correction is a ... mirror ... than 100% ... zonal ... toward down ... graph. ... Steve, That's sounds like a pretty...
... field as I'd ... panoramic images, ... you view them ... coating site) ... talent. ... Coolidge Hi James, I was at my astronomy club meeting last night and...
... From: Bob May To: atm_free@yahoogroups.com Sent: Friday, February 25, 2005 3:35 PM Subject: Re: [atm_free] Re: Masking Expirement I put it up on my website...
... Here's a summary of the numerical results for John's mirror as tested before the final touch up runs: Johns masked Foucault readings dated 2-20-05 P-V .122...
Steve: I have had some experience comparing Foucault and nulled interferometric measurements of the same mirrors: 1. An 8 inch F 4.3 that I made on the knife...
Scott: Thanks for sharing these examples. They do seem to corroborate what I have seen when testing mirrors figured using the Foucault test. They generally ...
Hey: I have a question for the math guys out there. Recall that the Foucault test gave a Strehl of about .95 for John's mirror while at the same time his RTA ...
John: I think you should use an 18-point cell. 9 might be sufficient but it's not that much harder to build an a8-point cell. I've never tested a mirror in the...
I've run plop to design an 18 point cell. I have a question concerning the "cell parts". The software almost makes me think the end points of the triangles are...
John, I don't recall the thickness of your 18" mirror, or even if you told us the mirror thickness. I have a 9 point cell on my 22" mirror which is 2 3/4"...
James, ... I have some ideas on this. The RTA is related to the second derivative of the slope of the surface, so I think you could make an optic at any Strehl...
Scott, ... Thanks very much for this account. (I now know another piece of the story of that 10" f/5 you mentioned.) I suppose we are only now coming into...
1. The ends of the triangles given by PLOP refer to the center points of the flotation pads. 2. Nobody uses felt pads any more, except old guys from the...
In other words, I think RTA is only loosely related to Strehl ... likely also> improve the RTA, but not necessarily. To have a high RTA in this case, you must...
... entries ... the ... I've just now browsed through a couple days worth of traffic, and I'm afraid I only have time for a quick look at some of the data and ...
... From: "John" <imas1@...> ... Hi John, Thank you for the feed back, it is greatly appreciated! I don't get to do a lot of observing, especially with...
... points of the ... Use ... at their ... flexibility and ... and ... obsolete. ... about how ... their ... platinum or ... Thanks Richard, My frugality is...
The article specifies a magnification of about 100x for the inspection optics. It also shows how to make a good enough microscope from an EP. I'd suspect that...
James and Mike, ... Thanks for pointing out my error. I'm not sure if I forgot to divide by two to take the double-pass null test into account, or whether I...
Group, Sorry about the last blank message. Mike, I have a few comments on ... I don't think sparse sampling by itself can be the cause of the the amplitude ...
Hi, This is an excellent discussion. There's little that is more relevant to ATMs than understanding the most commonly used test. ... I would be very curious...
