Home-made coma corrector and/or FF?

[bojan]

I was wandering, if anyone ever attempted to build coma corrector or FF from surplus optical parts (for example, it should be possible to build the meniscus from elements from air spaced achromatic objective lenses).
I found some links on the web, like this one: http://scopes.wikispaces.com/Two+Element+Coma+Corrector

I will certainly try it myself.. and any previous experiences would be helpful and much appreciated (but they won't to stop me from coming to my own conclusions about futility of the effort ;) )

[ZeroID]

Interesting, I have access to heaps of small optical elements from laser printers\copiers, projectors, camera lenses and the like. have to see if I can do something useful with any of them.

[troypiggo]

What software is that they're using for spot diagrams etc?

[bojan]

It is OSLO
http://www.lambdares.com/education/oslo_edu

I played a bit with my idea (attached).. it seems that, if "my" corrector doesn't correct, at least the image is equally blurred across the whole FOV :lol:

[ZeroID]

Ta for the link Bojan, I was thinking the same thing as Troypiggio. Must pull it down and have play with it. I can see me building an optical bench one day ... another project :rolleyes: :D

[ZeroID]

OK, downloaded the software, read the starter documentation and followed the example lesson. Phew !!
Very complex and clever piece of software, I'll never learn to use it properly but very instructional and it filled in a few holes in my optical understanding. I'm starting to figure out how a coma corrector works now. Could be useful ...

[troypiggo]

Yeah, thanks for the link bojan. Fascinating.

[ZeroID]

You played with it yet Troy ?
I did the first mirror example then tried it using my own mirrors (250 f5 & 114 F8) as models and entering the relevant data to see if I understood the parameters. VERY educational

[troypiggo]

Not yet. Hoping to over the weekend.

[pixelsaurus]

While I was wandering around the net this morning, I came across this site that has all the "Telescope Making" mags on pdf. As I'm researching things to do with my 350mm f/4.3 mirror, I took the time to go through all the contents of "Telescope Making" and found an article of building coma correctors using off the shelf optics. I have no idea of the article contents as you have to buy the issue ($US3.95) to read it. However here it is. http://www.kalmbachstore.com/tmkpdf045.html