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Posted by David Filipowski on June 21, 2003 15:25:24 UTC

Actually, refractors are making a bit of a comeback regarding astrophotography lately. But I doubt we will see them ever approach reflectors and SCT's in popularity any time in the near future.

I believe this is to due to two main factors: Aperture Fever and Cost. Where as a 12 inch Newtonian reflector of the Dobsonian variety is within reach of most people, and will give images comparable to a 9" refractor when you factor in the central obstruction of the secondary mirror, a good quality 9" refractor is only within the financial reach of a very few. That and the size of such, with an f-ratio to preclude severe chromatic abberation, would require a barn! Not a small dome in the the backyard. Maybe not a barn, but I think you get the idea.

If you take a look at the photo gallery in the latest Meade catalogs, though, you will find many of the pictures were taken using their APO refractors. Inch for inch, the refractor does have the ability to show more detail - contrast - than either a reflector or SCT. Simple reason being the lack of a central obstruction from the secondary mirror. This rule eventually falls apart as one goes to larger lenses which, no matter what you do, will absorb some of the light passing through the system. This is why no one builds 300 inch refractors on top of the Andes.

I knew I would have a pie thrown at me for saying refractors give a sharper image of the planets! But I stand by that. For the coming encounter with Mars I will be using my AR-5 just about exclusively for visual observation. If I was planning on tossing $10,000 into CCD gear, I'd go with my 12" LX200. But still use the AR-5 for eyes-on viewing.

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