I forgot I had taken a Ronchi image trying to show the edge. See it in the Files \ Dale Eason \ronchi.jpg I have forgotten the exact details but I think it...
For all you ronchi experts out there I have tried simulating the ronchi pattern from Barry's interferometry data and compared it to the real ronchigram. See...
The other thing I notice about the comparison is that the real seems to have less bend in the lines. If I have all other parameters correct then this must...
Maybe it was not an 80 lpi grating for the original??? How would a 100 lpi do a little closer to ROC? Of course I don't know what gratings you might have...
I took some images. I'll put up the "best" one showing it the worst. How bad does it look? Mitch of course I kept it VERY smooth up until I started using...
Do you have a thermometer? If you buy one, go to a real camera store where they have developing stuff and get a good immersible thermometer. That will...
Mitch, What are you asking about in the first part and what is the second part about temperature trying to say. You have me puzzled. How do you get smooth...
... Do you think it is too rough. And the temp is too low so the pitch is too hard ... polished ... ACCULAP. Most people don't like it but It seemed to work...
Ok, now I understand. Acculap is a synthetic pitch. So I think most would call it pitch. But never mind. Perhaps others can comment on your Foucault image...
... roughness. ... mirror ... much ... I ... some ... probably ... I question your comment on a turned edge. At the last ATM meeting I went to the edge was...
Put up some ronchi's. The outside image appears to have a bulge at the edge indicating the edge is still a long zone. Hopefully not much according to my...
Mitchell... On the Foucault pics you should get the left side of the mirror to show some shades of gray also. The entire left side is in shadow. The Foucault...
If you've got the rest of your scope ready just mount up the uncoated mirror and gve it a try. Even in this configuration you'll have enough light for the moon...
That image does give a better idea of the edge. It looks better. Did you look at the example image I talked about (photos\atm_ken_hunter)? Try and get one...
From what I see on the latest photo posted, he's very close to a sphere, the KE is near or farther out than the edge zone and there is some zonal roughness...
OK, I've added a couple of new (old) photo's to the Yahoo folder in the photo section. A good look at a parabolic mirror from the 70% and edge zones. The...
These are of a 10" f/5 Zambuto mirror, the 70% and edge photos are at http://www.mag1instruments.com/optics.html along with some tif files (unstretched). They...
Hi Mitchell: Looking at the photos and assuming the knife is on the right and the labels are correct on the Ronchi images... What you've got is a mildly...
... roughness. ... Second page of photo's, called Mitchell's Pics http://ph.groups.yahoo.com/group/atm_free/photos/browse/d05c I Got some more materials for...
... show some ... Foucault and ... Yes I can. For the ronchi it got too bright and the Foucualt I thought it showed the shadows better. I tried to get some at...
... the ... If ... output ... Group's ... his ... trying ... say ... bit ... a ... It's a 6" F/6.5 how much correction are you expecting? If you don't believe...
OKAY I need to make a few things clear. 1. The Ronchi's were mislabeled before. They are correct now, it is indeed a parabola. 2. I took some more images they...
OKAY I need to get a few things clear. 1. I had the Ronchi's mislabeled before, they are right now. It is indeed a parabola. 2. I took 6 new Foucualt pictures,...
Mitch, Well it is starting to look like very large bumps. Too much. They still could be exagerated by the imaging process. Another way to tell is to take...
You want to jack up the brightness of the LED a bit. This will provide more light to make the image brighter for any particular exposure length. You may have...
Looks to me like the mirror has a very slight TDE as the hook to one side isn't quite matched to the hook to the other direction of the lines. I'd normally...
I'd normally consider that mirror to be a decent ... Why does everyone keep saying it is a sphere? It was already confirmed to be at least 1/4 Wave and since...
Perhaps because they are used to seeing faster mirrors. But also because we no longer remember the lines per inch of your grating. Your ronchi lines tend to...
