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Drakkith
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Feb24-12, 03:35 PM
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Quote Quote by sravet View Post
We aren't planning on any zoom, just two fixed lenses. The experiment in his book showed two convex lenses mounted with clay to a yardstick, with the smaller eyepiece lens placed just behind the focal point of the objective. We want to buy a handful of lenses to try different focal lengths and positions to see what happens. What do you consider very very long? The longest I've been able to find is a 1000mm that I was planning to get for the objective.
What is the diameter of the objective? If it's fairly small 1000 mm might be ok. It really depends on how much abberation you can take and still be satisfied with it. Also, you will have zoom with any setup, otherwise it's not working correctly.

I studied optics a long time ago on my way to an engineering degree, but basically he has read a couple youth science books on microscopes and telescopes, and I've spent a couple nights reading up on this forum and others on the topic, and that's about the extent of our knowledge. We'll keep reading though. Any pointers you might have to good introductory WWW pages would be great.

thanks,
--steve
A quick google search for "building a telescope" revealed multiple sites that seem to be good. Here's a link to one.
http://www.funsci.com/fun3_en/tele/tele.htm

Also, you might be able to find some objectives and various other parts at this site for a good price: http://www.surplusshed.com/new.html