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meteorite
Vendor (meteorites)
Reged: 01/28/06
Posts: 270
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Hello Everyone,
I asked the following question over in the refractor forum and it was suggested I pose the same question here in the reflector forum. I would appreciate any comments or opinions. Thanks
I currently use a very nice 6 inch f/8 reflector for lunar and planetary observing. It is also a great scope for double stars and the brighter DSO objects. I really like this scope, for various reasons.
I have been considering purchasing a 120 mm Skywatcher ED, refractor to basically replace my 6 inch reflector. For only $1500.00, the Skywatcher comes with an RACI finder, rings, 2 inch crayford focuser and dovetail (as well as two eyepieces). This is a really good deal, IMHO.
I am thinking the refractor would give nice contrast with very pinpoint stars (which is what I like)
I would appreciate opinions on whether the refractor would provide a more pleasing view via for example, better resolution, quicker cooldown time, more contrast than the reflector, etc.
I realize only I can decide if the refractor is right for me; just seeking others opinions. Concerning my viewing habits, I place quality of views over quantity. For me aperture does not always rule. I am not interested in AP, just visual.
Thanks everyone.
-Walter
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Patrick
Postmaster
Reged: 05/16/03
Posts: 7811
Loc: Franklin, Ohio
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I don't think you will see a lot of difference between the two scopes. I suspect the contrast differences will be slight due to the reflector's larger aperture and small secondary size.
The length of the 6" f/8 is approx 48" while the 120ED is close to 40" once you add the diagonal and dew shield, so there's not much difference there. A 6" f/8 Newtonian is small enough to mount on a CG5 class mount if you want tracking.
All in all, I'd say put the $1500 towards a good mount, unless you just want the refractor or are planning on using it for imaging.
Patrick
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10" f/6 Truss Tube Newtonian
Celestron C6S-GT SCT
AT66ED Refractor
Oberwerk Ultra 15x70 Binocular
475B Geared Tripod & 501HDV Head
Celestron Regal 8x42 Binocular
Canon XSi; Meade DSI;SPC900-NC
Vixen GP2 Photo Guider Mount
My Astronomy Pages
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sailor70623
scholastic sledgehammer
Reged: 01/12/08
Posts: 944
Loc: Ok.
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The 2 scopes are so much the same you aren't going to notice much of a difference. The refractor may win on a few DSOs, but mostly will be better on splitting stars. I would get a faster refractor for a wider view, or replace the reflector with a larger, faster reflector to go with this new scope. The price is good, but I would try something different, instead of more of the same.
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Corornado PST
LB 16" & 12"
Z 10"
LX50 8"
8" CPC
ETX127
102&90mm MAKs
80mm Richfield APO
70mm refractor
ETX60
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jayscheuerle
Post Laureate
Reged: 01/16/06
Posts: 4076
Loc: S. Philadelphia, PA
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I have a 6" f/5 and the Skywatcher 120ED. The reflector has a curved spider to mitigate diffraction spikes, yet I DO notice the better contrast in the 120ED when viewing bright objects Jupiter and the Moon and there is also a quality to the stars in the refractor which is hard to put a finger on. The reflector does go slightly deeper. The biggest difference is acclimation time. Because of my urban sidewalk viewing, I can't leave my equipment unsupervised on the sidewalk to cool down for 30 mins, but even if I could, at this time of year the temperatures are dropping too quickly for my newt's mirror to ever catch up (unless I was up REALLY late). The 120ED's cool-down time is negligible (a benefit of a doublet), so it almost always tosses up a better view, especially right off the bat. The exception might be for low-mag open clusters where thermal problems don't show up as much and diffraction energy isn't an issue.
Of course, the 120ED costs more than any other scope I have, especially once I put it on an LXD75. Is it worth the cost difference? Probably not, but I didn't have a scope with tracking or goto and I wanted to sketch at high magnifications. My viewing sessions are usually under an hour as well. The combination of these two made the 120ED very attractive. - j
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Fight indignorance!
The Green Goblin - 12" of dobsonian excellence!
The PortaBowl-a $100 4.5" f/8 ball-scope YOU can build!
Eero2-a 6" f/5 ball-scope you probably can't. 
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gtown1
member
Reged: 11/07/08
Posts: 69
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I agree that you should differentiate--buy a scope that will give you total different capabilities. I would buy a larger Dob--maybe in the 10 to 15 inch size.
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Happy owner of an Obsession, 18 inch Ultra Compact and a Mag 1, 12.5 inch Porta Ball.
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EdTheEdge
super member
Reged: 04/10/09
Posts: 140
Loc: Lomita, CA
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I hate threads like these. I have a Celestron 6in f5 reflector and have been jonesing for an EON 120. 
Cest La Vie I guess.....
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Scopes:
Celestron SP-C6 F/5
Orion ST80 F/5
Orion 90mm F/10.1
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Mount:
Vixen Super Polaris
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Eyepieces:
Orion 25mm Sirius Plössl
Orion 15mm Expanse
Orion 10mm Ultrascopic
Orion 7.5mm HightLight Plössl
GSO 2X Barlow
Lumicon ND25
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Torrance,CA
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Patrick
Postmaster
Reged: 05/16/03
Posts: 7811
Loc: Franklin, Ohio
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Quote:
I have a 6" f/5 and the Skywatcher 120ED. The reflector has a curved spider to mitigate diffraction spikes, yet I DO notice the better contrast in the 120ED when viewing bright objects Jupiter and the Moon and there is also a quality to the stars in the refractor which is hard to put a finger on.
The 6" f/5 has a larger central obstruction than the 6" f/8, so it's understandable that the contrast would be slightly reduced.
Patrick
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10" f/6 Truss Tube Newtonian
Celestron C6S-GT SCT
AT66ED Refractor
Oberwerk Ultra 15x70 Binocular
475B Geared Tripod & 501HDV Head
Celestron Regal 8x42 Binocular
Canon XSi; Meade DSI;SPC900-NC
Vixen GP2 Photo Guider Mount
My Astronomy Pages
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jayscheuerle
Post Laureate
Reged: 01/16/06
Posts: 4076
Loc: S. Philadelphia, PA
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It's not just the CO, but the spider as well. The curved spider IS nice, but no spider is even nicer. - j
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Fight indignorance!
The Green Goblin - 12" of dobsonian excellence!
The PortaBowl-a $100 4.5" f/8 ball-scope YOU can build!
Eero2-a 6" f/5 ball-scope you probably can't.
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charles genovese
super member
Reged: 02/04/06
Posts: 132
Loc: Madisonville Louisiana
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I have an RV6 and SW ED 120- both with perfect optics, and I frequently take out 2 or even 3 scopes to observe ( occosionally 4-add a C8 and a FS 102) (all on mounts that roll). The RV 6 and SW 120ED are virtually identical on the moon and planets and on DSO's as long as the field of view is less than 1 1/2 degrees. The Newt, with a 1 1/4" focuser is limited to a 30mm 50 deg eyepiece, whereas the refractor with a 40mm 70deg eyepiece gives nearly 3 degrees. Of course the refractor costs 5X's as much, and if the primary reason for the refractor is wide field low power viewing and money is a factor get the acromat! As for cool down, I always put an inexpensive squirrel cage fan ($10 bucks at wallmart) on the back end of the Newt and in 10 or 15 minutes the views are already at 90%.
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