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Possible use of a 10" SCT with no corrector?

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#1 Guest_**DONOTDELETE**_*

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Posted 20 May 2004 - 09:01 AM

Greetings,
A friend of mine has found in his club a primary&secondary mirrors of a 10 inch SCT. He was told that the original correcting plate was broken long ago...
The intended use of these optics was to demonstrate the light path inside a telescope during public events. However, since the mirrors are in good shape I was wondering of the possibility of restoring the telescope for observations.
Is there a way of getting a corrector-plate for this purpose? is there any other way of eliminating the spherical abbarations (ie using some sort of lenses near the focal point , where usually a focal reducer or a barlow are used)? Is there a point of doing this at all? Does anyone have any othere idea for a practical use for these optics? :question:

Any input would be greatly appriciated,
Assaf.

#2 Starman1

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Posted 20 May 2004 - 10:42 AM

Assaf,
Vixen corrects the aberrations in their Cassegrain scopes with a multi-lens corrector in the primary baffle tube. Their secondaries are held in place with a normal, 4-vane, spider. I'm sure the design is proprietary, but an optical lab may be able to make a correcting lens that can attach to the back of the tube. Just bear in mind that a complete optical tube assembly can be had for ~$800, so if the manufacturing expenses exceed 50% of that, it may not be worth trying to make a telescope out of complete optics.
Don

#3 BluewaterObserva

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Posted 20 May 2004 - 11:13 AM

I curious?? What happens if you try to use it as is???
Does it come to focus??? I can think of a dozen experiements I would play around with using such a thing.

#4 Starman1

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Posted 20 May 2004 - 01:25 PM

It will have severe spherical aberration. Only the centerpoint would be focusable, and that image wouldn't be good. The mirror could be reground as a parabola, but I wouldn't want to see the figure of an f/2 parabola. The optics you have must have some form of corrector.
Don

#5 BluewaterObserva

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Posted 20 May 2004 - 03:12 PM

It will have severe spherical aberration. Only the centerpoint would be focusable, and that image wouldn't be good. The mirror could be reground as a parabola, but I wouldn't want to see the figure of an f/2 parabola. The optics you have must have some form of corrector.
Don


Interesting.... Sounds like a great candidate for I.R/ and Near I.R. work.... lol

I actually never though about what an SCT would do without it's corrector plate. before.

#6 Steven

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Posted 20 May 2004 - 04:00 PM

Any ATM in the club ? It would be a great project to make your own corrector :cool:

#7 BluewaterObserva

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Posted 20 May 2004 - 04:05 PM

I wonder what a refigure outfit, may charge to try to make it into a f/2 parabola??? That would be an ultra cool unique scope. Dang, if it was free, I'd have to give that a shot actually.... Maybe try a paracor on it or something even.

#8 wilash

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Posted 20 May 2004 - 07:34 PM

I would call the manufacturer and ask how much a new corrector would be. A SCT corrector is very difficult to make. You could also use the primary in a Newtonian configuration, but spherical abberation will be apparent.

Or find someone with a 10" SCT who broke the primary, but the corrector is OK.

Another use would be a flower pot. The hole at the rear is good for drainage. It could be a very cool lamp shade. Cap the rear and use it as a fire bucket or waste basket. Or use it as a case to transport an 8" SCT. :roflmao:

#9 Guest_**DONOTDELETE**_*

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Posted 21 May 2004 - 10:03 AM

Another use would be a flower pot. The hole at the rear is good for drainage. It could be a very cool lamp shade. Cap the rear and use it as a fire bucket or waste basket. Or use it as a case to transport an 8" SCT. :roflmao:





#10 gazerjim

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Posted 21 May 2004 - 07:45 PM

Any chance of making it into a Maksutov?

#11 Don W

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Posted 21 May 2004 - 08:30 PM

That would require a big thick chunk of optical grade glass for the meniscus that would then have to be ground. Yeah, it's possible, but the amount of work........whew!!

#12 half meter

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Posted 21 May 2004 - 09:21 PM

I'm sure it would make a great solar hot dog cooker, especially if it had severe abberations.

Otherwise, it'd burn a hole right through the dog :dabomb:

#13 Victor Kennedy

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Posted 22 May 2004 - 03:00 AM

Mount a halogen bulb where the secondary used to be, stick it on the hood of your car, and use it to burn through the retinas of those idiots who refuse to dim their high beams.

#14 Don W

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Posted 22 May 2004 - 09:00 AM

I'm sure it would make a great solar hot dog cooker, especially if it had severe abberations.

Otherwise, it'd burn a hole right through the dog :dabomb:


Hey, that's the best idea yet. Can you see the crowds at star parties at noon when you start pulling cooked franks out of your Meade 10" OTA?

#15 half meter

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Posted 23 May 2004 - 06:24 AM

:roflmao:

"I know you're hungry, kids. Daddy is hurrying. He's almost got the hot dog cooker polar aligned!"




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