They say the only stupid question asked, is the one not asked, so here goes. Where on (in?) a telescope does a focal reducer go? I was looking at the 5 in. Intes Mak and it came with a focal reducer, but I was wondering if I would be able to get one and put it on, if I got the new 5 in. SkyView Pro Mak from Orion. Thank you.
Focal reducer
Started by Josh, 07/19/2003 06:50PM
Posted 07/19/2003 06:50PM
Opening Post
Posted 07/19/2003 07:20PM
#1
All the focal reducers I have ever seen have two sets of threads--a female and a male--sized to fit an SCT (or mak or anything using that size attachment). You thread it directly to the back of the Tube. Then you thread whatever you need (a visual back, or a diagonal, or a camera attachment) to the back of it.
It is usually used on SCT and Mak design because they have lots of focuser travel (so they can use it), and so much focal length (so they need it).
SOme devices (like off axis guiders) can contain their own focal reducers, which are occcasionaly removable.
Alex
It is usually used on SCT and Mak design because they have lots of focuser travel (so they can use it), and so much focal length (so they need it).
SOme devices (like off axis guiders) can contain their own focal reducers, which are occcasionaly removable.
Alex
Posted 07/19/2003 08:47PM
#2
Focal reducers usually are positioned inside the focal plane to project at the FR's reduction ratio. They are readily available for CCD cameras, CATs, and refractors as reducer/flatteners (e.g. Takahashi, Astro-Physics) down to .33x reduction, with photo-visual limitations.
If the Intes FR has standard SCT threads, it is possible to use the FR with an additional 36.4mm LAR adapter which converts the Orion Mak's visual back to standard SCT male threads. There may be some vignetting depending on the configuration.
Background info:
http://ganymede.nmsu.edu/holtz/a535/ay535notes/node26.html
If the Intes FR has standard SCT threads, it is possible to use the FR with an additional 36.4mm LAR adapter which converts the Orion Mak's visual back to standard SCT male threads. There may be some vignetting depending on the configuration.
Background info:
http://ganymede.nmsu.edu/holtz/a535/ay535notes/node26.html
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