How long is the 80 Leon? I use a Tak FS60-C, and while it's only 60mm in clear aperture, it does a fine job guiding my FS102 at 820mm f/l. The FS60-C is about 35cm in length including the dew shield, add a little for the guide camera. Very nice when you swap scopes and use the 102 to guide the 60. Great optics in both as you'd know. Monte Wilson also uses an FS60-C to guide his FSQ-106.
I use one to guide the 100ED and the SN10. I also use a 0.5 focal reducer to make it about 600mm f/7. Also bolt it directly to your imaging OTA to minimise flexure.
How about this Orion from Bintel:
.
* Multi-coated 80mm f/5.0 optics deliver bright, wide-field images.
* Solid metal 1.25" rack and pinion focuser.
* Sold as optical tube assembly only, no accessories.
Weight 1340g.
Tube Length: 40cm
Tube Diameter: 92mm
Note: The OTA will require either a diagonal or extension tube to reach focus.
Last edited by Geoff45; 28-11-2008 at 12:15 PM.
Reason: improve
How about one of those mirror lenses 500mm F8, plenty of them on ebay for up to AU$200 (new)? They are 15-20cm long max.
I intend to use one myself for guiding.
How about one of those mirror lenses 500mm F8, plenty of them on ebay for up to AU$200 (new)? They are 15-20cm long max.
I intend to use one myself for guiding.
I have one of these Bojan - and they are way too dim to use as a guide scope. I've tried!
I have one of these Bojan - and they are way to dim to use as a guide scope. I've tried!
That's not good ..
I have also rubinar 1000 F8.. I saw some people using them for guiding, they are pretty short (~25cm) and light (2kg). Perhaps this one would be better?
That's not good ..
I have also rubinar 1000 F8.. I saw some people using them for guiding, they are pretty short (~25cm) and light (2kg). Perhaps this one would be better?
I guess it'd depend entirely on whether there was a really bright star handy.
Leon, as Geoff mentioned earlier, get the Orion Short tube 80, it's excellent as a guide scope, it's light and quite cheap.
It's what I use with my Orion guider.
leon - here are a couple of mine. I use two FS60-C clamshells to give it total rigidity - but one is fine. I just had two so I use them. Guide stars are usually no trouble to find, so I don't use rings. If this becomes a problem, I'll go and get an Orion X-Y GuideStar Finder. I have a little extra length in this shot because I've got both my camera angle adjuster and field flattener in the image train.
I think Leon was only on about guiding. True, crap for imaging .
I also use my FS-102 to guide my FS60-C for some terrific widefields on occasion. I reckon it adds a great dimension to a setup to be able to swap their duties from time to time. If Leon already has a Tak, it kinda makes sense to make both Taks - some accessories will then work on both.