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Post by Dragon Man on Dec 14, 2013 15:37:49 GMT
Depends on the brand.
The most common ED80 is made by Synta and sold under the brand names of Skywatcher (standard, Pro, Evostar, and Black Diamond), Orion, Saxon, and a few others. They are all the exact same scope but painted different colours and have a different brand name printed on them. They are ALL f7.5 and 700mm Focal length.
But some other brands of 80mm ED's are slightly different in Focal ratio and Focal length, like Explore Scientific, Vixon, Celestron, Astro Professional, etc.
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Post by Deleted on Jun 19, 2014 12:15:35 GMT
I have just bought an orion shorttube 80 with the counterweights to piggyback on my LX90 10inch as a finderscope. Before this I had only used a flip mirror. I suspect everything is just a bit too heavy for the mount. I will put it together this weekend but as Ken will tell you the weather has been pretty ordinary around these parts lately. I had a cataract op last week so with a new eye and a new scope I will let you know how it all works out. Paul
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Post by Deleted on Jun 19, 2014 13:41:56 GMT
Davy and Ken Do you think my starshoot autoguider and 50mm guidescope is suitable to use as a finderscope for the LX90. If so,what software would you recommend for the starshoot? I really think the orion shortube 80 and all the kit will be far too heavy and will delay mounting it if you reckon I should give the starshoot a proper go . Thanks ,Paul
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Post by Dragon Man on Jun 19, 2014 14:11:55 GMT
Paul, a Starshoot in a 50mm scope will have a really small FOV. Nothing like what a finderscope should have, that is if you are going to use it as a finderscope. The chip will only show you a small central portion of the field. Check it in CCD Calc and it will show you the FOV you will get. Enter all the numbers into the CCD calc software. www.newastro.com/downloads/ccdcalc/ccdcalcfull.exe
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Post by davy on Jun 19, 2014 16:14:27 GMT
Yes ken's advice is spot on..with a bigger aperture scope it would give a bigger fov and make it easier to find targets..as ken says depending on what you want to do with it.
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Post by Deleted on Jun 19, 2014 18:27:18 GMT
Paul you can piggyback no problem! I have the 8" LX90 and I piggyback a Starwave 70ED on top (im just guessing... but think it will be a good bit heavier than the ST80). Only issue is balance...but you already have that sorted. Your 10" will handle it no problem!
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Post by Deleted on Jun 19, 2014 20:15:39 GMT
I love my new 80mm APO. I have a reducer on my 80mm, so a 70mm f6 APO with no reduction, would have a comparable FOV. I this a 65mm would also be just fine, albiet slightly wider. For reference here is a shot with a 80mm reduced to ~f3.9. This should be real close to what you would expect from a 70mm. www.flickr.com/photos/leehemmingsen/14261505902/
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Post by Deleted on Jun 19, 2014 20:18:14 GMT
Opps late to the party. I see you already got a 70mm.
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Post by Deleted on Jun 19, 2014 21:27:14 GMT
Thanks for that fellas Now that I can see, I will mount the ST80 and let you know. Paul
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Post by Deleted on Jun 22, 2014 8:25:28 GMT
G'day fellas I hope this image uploads ok.
I have piggybacked both the 50mm and the ST80. I took a guess at where the counterweight should be positioned. The mount handles the weight pretty well. All I need now is some clear sky Paul
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Post by Deleted on Jun 22, 2014 10:09:36 GMT
Me again Should I put both the 6.3 reducer and the .5 reducer together on this system. What would that make the F value? Also, for an alt/az system, is the position of the counterweight crucial . It doesn't seem to make any noticeable difference to the mount if I shift the counterweight up or down the dovetail a couple of centimetres. Paul
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Post by davy on Jun 22, 2014 10:17:24 GMT
Scope Is looking Great paul ..scope weight suppose if it not dragging down at the rear it must be close to it's balance point. . Chris has an lx90 with balance weight ect im shure he will have some answers for you. .davy
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Post by Deleted on Jun 22, 2014 18:37:33 GMT
Looks great Paul! And I have heard using a 0.5 and 6.3 reducers together can work well. I haven't tried this though. I just use the 0.5 on its own. Regarding balance...I kinda gave up trying to get perfect balance... Just release the lock and try get it so that where ever you leave it...it stays in place. I settled with 'close enough'
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