Hunting for a 2" ED, Apochromatic non-aspheric lens design Focal reducer.

[AstroGuy]

Hi all,

Wondering if anyone can help:question:

I have a 8" Mak and would like to place a 2" focal reducer in the focal path. Most focal reducers on the market these days are achromatic and, have aspheric lens design (this spells chromatic abberation in a Mak). They are mainly created this way because they are mostly made for SCT scopes. Mak's don't have such pronounced SCT chromatic drawbacks and, a achromatic, aspheric lens design would only distort the light path in such scopes and create chromatic abberation in my Mak.

If you would like to know about how lenses work check these links out:

http://en.wikipedia.org/wiki/Lens_(optics)

http://en.wikipedia.org/wiki/Aspheric_lens



:question: My question is:

Does anyone know where I can get a 2" ED, Apochromatic, non-aspheric lens design focal reducer? Or even if such a thing exists yet?

[MikeyB]

How's your German? :)

Intes Mikro Reducer 0.6x eg for Maksutov Cassegrains (http://www.teleskop-express.de/shop/product_info.php/info/p2477_Intes-Mikro-Reducer-0-6x-e-g--for-Maksutov-Cassegrains.html)

[DavidU]

Here is an article by someone who had success.
http://www.astromart.com/articles/article.asp?article_id=661

[AstroGuy]

Thanks Dave,

The Article was very useful. Unfortunately the Author came across the same problems I'm dreading. I definitely know now what brands not to use! ;)

[AstroGuy]

Hi Mike,

I checked it out and it does sound like what I am looking for. Unfortunately for the price they are asking, I'm not going to chance it at the moment. I've seen a lot of focal reducers advertised that state they are ok to use on a Mak. later I find articles and threads in forums that state the opposite. At a hefty $350.00 AUD (not including postage) I'd rather not take the chance without researching The Intes Brand a little more. I haven't found any negatives on it so far, which I suppose is a good sign :)

At those prices though, I wonder if I should just get a $50.00 2" GSO .5x focal reducer and a Ba'ader fringe killer/semi APO filter? If I can get my LCD Digital Optical Filter Project up and running effectively ASAP I might not even need the filter!

Thanks very much for the info Mike :thumbsup: If I do get the Intes one I'll let you all know how it performs.