Old 16-04-2011, 08:25 AM
garymck (Gary)
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Join Date: Aug 2005
Location: Geelong
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Smile ED80 Focal reducer test

thought people might be interested in a first test of a Skywatcher Focal Reducer for a ED80 as I haven't seen anything posted anywhere. Very happy with the result. The ED80 is about 4 years old and a Saxon version, borrowed from a friend to use until I score a job and replace my sold off stuff There are a few gotchas with the Focal reducer though. Firstly it only screws to the original focuser tube and does not fit a two inch adapter. So if you have added an aftermarket focuser yo will need an adapter. The only place I could find one was at:


I have ordered one and cost was 27GBP including airmail.

The output side of the focal reducer has a 48mm filter thread, so I had to hook some bits together and fluked the correct spacing - actually I'm .5 of a mm too long. A friend is going to machine up a proper adapter for me.

The results are excellent, even allowing for the fact that I can't guarantee everything is totally square due to my kludged connection. Images are in order:

top left, bottom left, top right, bottom right, center. They from a single 120 sec shot taken with a QHY8. No processing except for de bayering and histogram adjustment. Magnified 400 percent. Image scale is a bit over 3 arc secs/pixel. This scale may hide problems a bit so would be interesting to try a camera with smaller pixels.

Will email original fits file to anybody who wants it, though beware its 9mb!!

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Old 16-04-2011, 08:38 AM
[1ponders]'s Avatar
[1ponders] (Paul)
Retired, damn no pension

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Join Date: Nov 2004
Location: Obi Obi, Qld
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you might want to compare it with these
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