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ebusinesstutor
sage
Reged: 07/01/09
Posts: 468
Loc: Nanaimo, BC, Canada
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I purchased an 8" dob and an 80mm ED refractor. My plan was to use the dob for deep sky and the refractor for grab and go.
But it hasn't turned out that way.
The dob only takes one more trip to take out and each of its two parts are no more heavy or awkward than the refractor and mount together, so I haven't really found I needed the grab and go capability as much. For the single extra trip, I could have much bigger light gathering.
And I found that the dob gives me better views of the moon and Jupiter and MUCH better views of objects like M13 and M31 my first two DSOs. So my small refractor has been languishing.
Last week, I came across the Pleiades for the first time. At the time, I had my 8" dob with my 8-24mm Hyperion Zoom. But at it's lowest magnification (50x in my dob), I was only seeing part of the Pleiades. The funny thing is that it actually looked better through my 9x50 RACI finder scope than it did through the dob at that point!
I had just ordered a 36mm Siebert Observatory eyepiece, so when it arrived, I was excited to be able go get its lower power plus 70 degree field of view (FOV) on the Pleiades.
And I wasn't disappointed - Through my dob, the Pleiades looked fantastic at the 33X magnification and wider FOV.
But I started wondering, what if I could get down even further? So I brought out the C80ED and popped in the Siebert 36mm. This brought the magnification down to 16-17X. The stars were pinpoint and I could see the entire Pleiades and surrounding stars.
The moon was up and nearly full, so the viewing wasn't perfect, but it was quite lovely. So perhaps my small refractor has some uses after all. I was thinking I had jumped in too soon buying it.
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Garland Coulson
Orion XT8i Dob & Celestron 80 ED on a Vixen Porta Mount Mini
Baader Hyperion 8-24mm Click Zoom & Siebert Observatory 36mm
Siebert Black Knight Binoviewers
SkyWatcher Observing Chair
Celestron Skymaster 15x70mm binos
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molniyabeer
Confused and Asleep
Reged: 01/08/05
Posts: 2559
Loc: Central Coast, California
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Congrats on the view! Many of the larger open clusters (M45, 44, Double Cluster, Alpha Perseus association, etc.) are much better served by low power and wide field fiews. Take your 80mm out tomorrow morning and see if you can catch Mars on the edge of M44. In my 11x 70mm binos a couple of years ago it was a stunning sight. I missed the best of the current cunjunction this weekend but it should still be pretty.
Clear skies.
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Steve
16" Meade LightBridge (Beowulf)
10" Hardin DSH, StarMax 127mm Mak, PST H-a
Oberwerk 11 x 70 binocs, Tasco 10 x 50 binocs
Santa Maria Clear Sky Clock
Figueroa Mt Clear Sky Clock
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lightfever
Pooh-Bah
Reged: 09/27/04
Posts: 1281
Loc: Macomb Michigan
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I also have an 80mm ED and the 36mm Seibert is on it's way (hopefully since it's lost in the mail somewhere  )
It will be interesting to see how it works in the 80mm, although I was thinking the sky background would be to washed out at that low magnification.
My 8" dob is my scope of choice for grab and go. Just pick it up in one piece and carry it out. It kills both of my refractors when it comes to detail and the amount of stars I am able to see.
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Mark
Tasco 15-TE 76mm
Sky Watcher 80mm ED
AT-111 Triplet
XT8i (with Woden re-figured mirror)
Discovery 12.5" f/5 Premium DHQ (PDHQ Split-tube Dobsonian)
12.5" f/6.3 Dob (Underconstruction)
Celestron CG-5GT EQ Mount
Celestron C4 EQ Mount
"Life is not about waiting for the storm to pass, but learning to dance in the rain" unknown
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HiggsBoson
Pooh-Bah
Reged: 02/21/07
Posts: 1118
Loc: Kal-li-fornia
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While it is hardly ever mentioned in the Refractor forum I feel that the wider field of view available from a small refractor is the primary reason to get one. I plan to get a 4” refractor which will provide a 4.5 degree field of view with a N31. The same eyepiece will produce only 1.7 degrees on my Newtonian. This is what is meant by a complementary scope.
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Michael
ATM: 6" F/9 Newtonian Travel Scope
ATM: 12.5" F/4.5 Real Soon Now...
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cuzimthedad
Just Be Cuz
Reged: 04/09/06
Posts: 3725
Loc: Sonoma, Northern California
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This is something one has to discover on their own. My 20" f/5 Obsession provides a 1 degree fov using the 31T5 Nagler. Same ep in my old 4" TV Genesis provided an almost 5 degree fov. I had my best view of M31, The Pleiades , and the Double Cluster using the latter of the combos. However, if you want to see the Maia Nebula surrounding the stars, then you need to crank up the mag in your scope which, unfortunately, eliminates the beautiful view of the cluster but does open up new territory in observing the nebulosity.
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Dan
20" f/5 Obsession
Antares 1529
TV102
Various Naglers, Ethos, UO Orthos and TV Plossls
The Off Fisher Lane Irregulars
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Kfrank
super member
Reged: 12/20/08
Posts: 164
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I too made this discovery. My SV80 gets much more use than the 8" dob because I enjoy open clusters and the refractor's wider views at low magnification show these objects much better than the narrow field of the dob. It's part of allowing oneself to gain experience which can result in a change in ones perspective.
Like the OP, I have found that it's not that difficult to carry the dob to the back yard. It just requires one more trip and no more setup time. Part of the reason the 80mm refractor gets more use is that it requires almost no time to temperature stabilize. I can carry it out on a moments notice whereas with the dob, or my ETX90, I have to have them out for a significant amount of time prior to observing. For me, that's what defines "grab 'n go". It's for those nights when the overcast sky clears at 10PM and there's Orion just sitting there inviting me. With a "G&G" scope I can carry it outside, take a look and not have to worry about temperature equalization affecting the view.
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Ken
ST80
SV80ED
ETX90 (Deforked)
Orion XT8
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Jeronimo Cruz
super member
Reged: 09/01/08
Posts: 141
Loc: Tucson, AZ
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I find that the best views ever of M31 for me come looking through my 5" refractor. I can see the entire galaxy in context AND the dust lanes. The high contrast, large TFOV combo of refractors can make using them very addictive.
I also prefer to view the moon through a small aperture refractor or masked down reflector because the image, for me, through instruments like these isn't too bright.
Also, one shouldn't forget the relative sharpness and ease of focus of refractors when compared to the typical Dob.
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Jeronimo
TeleVue 101 + Gibralter
Celestron NS11 GPS/wedge + Hyperstar
Photon Instruments 127mm + SV F50W2
Lunt Solar Systems LS60DS Ha + Celestron CG-5
Naglers, Panoptics, Radians, Nikon binoviewer
Fujinon 10x70 FMT-SX, 7x42 CD; Canon 15x50IS;
Pentax 7x50 PCF WP, 10x50 PCF WPII, 10x50 DCF SP
Work
20" R/C RCOS on Paramount + Tak FSQ
16" R/C RCOS on Paramount + TEC 140
16" Meade LX200 SCT + TV 76
Ethos, Naglers, Panoptics
Coronado Solarmax 90mm Ha
Coronado Solarmax 70mm Ca
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RussL
Music Maker
Reged: 03/18/08
Posts: 1925
Loc: Cayce, SC
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It's the very reason I bought my 120ST. Right now my favorite mag is 24x. I purchased an AstroTech 2" dielectric quartz diagonal for it and a replacement visual back with compression ring from ScopeStuff(part # FAS2) which gives me more in-focus travel. Now, to get some 2" eyepieces. I have found richfield observing to be wonderful, something I couldn't see in my other scopes.
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--Dawg, the Russell
"Akita mani yo." Observe everything as you walk. (--Lakota)
Celestron Celestar 8 Standard SCT, f10
Celestron 80mm Wide View ref., f5
Orion 120ST ref., f5
Criterion RV-6 Dynascope, Newt., f8, (c. 1962)
Sears Discoverer 60mm ref., f7, (c. 1973)
Celestron Ultima DX 10x50, 6.5 TFOV
Tasco 7x35 wide
Several mediocre eyepieces
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arpruss
scholastic sledgehammer
Reged: 05/23/08
Posts: 858
Loc: Waco, TX
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A fast dob can also be helpful for wide views. For instance, if I made a 2" focuser for my F/4 8", then a 36mm Siebert would give 22X with a respectable 3.4 degree TFOV (though with a 9mm exit pupil, there would be some vignetting by the eye). With the 1.25" focuser, a 32mm Plossl should give just over a two degree TFOV, which should contain M45.
Not actually having anything wider than a 30mm Rini, I get my really wide views through the 68mm finder riding on my 13" dob, or through binoculars. The finder is nice for this, because I can switch between the wide-view and a zoomed view of the same object just by walking between the two eyepieces. I still haven't seen the North American nebula in the dob, but it's easy when I put an OIII filter in the finder's eyepiece. So using a small refractor mounted to a dob is a really nice way to go, I think.
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Coulter Odyssey 13.1" split-tube
Coulter Odyssey 8"
Home-made 7.8" F/4 dobsonian travel scope
Home-made 68mm F/5.3 achro (typically used as finder on 13.1")
Skymaster 15x70
BPTs4 8x30
32mm Plossl, 30mm Rini, 27mm Kellner, 13mm Hyperion, 6mm TMB/BO Planetary, Owl 2X Barlow
Palm TX with AstroInfo and RescoViewer
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bsim
Pooh-Bah
Reged: 01/04/08
Posts: 1060
Loc: New York City
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Quote:
The moon was up and nearly full, so the viewing wasn't perfect, but it was quite lovely. So perhaps my small refractor has some uses after all. I was thinking I had jumped in too soon buying it.
A small wide-field refractor is a great complement to a larger dob. Wait until you go to a dark site and see the whole Veil or North American/Pelican nebulae with an OIII filter.
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ebusinesstutor
sage
Reged: 07/01/09
Posts: 468
Loc: Nanaimo, BC, Canada
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Quote:
It's the very reason I bought my 120ST. Right now my favorite mag is 24x. I purchased an AstroTech 2" dielectric quartz diagonal for it and a replacement visual back with compression ring from ScopeStuff(part # FAS2) which gives me more in-focus travel. Now, to get some 2" eyepieces. I have found richfield observing to be wonderful, something I couldn't see in my other scopes.
I have been contemplating a 120ST, Russl. One of the drawbacks with my C80ED is that I just find objects are too faint for it from my backyard. Perhaps it would be better in a dark sky site. But the 120 would be a step up, not as much as my 8" but perhaps enough that I would prefer it.
My goal is to spend more time observing a wider range of DOSs as most of my time until now has been the moon and Jupiter and I have only found M13, M31 and the Pleiades for DSOs. While observing, I will see if I feel I am not seeing the whole field and try some with the C80ED as well as the 8" dob. If I feel that low power rich starfield viewing calls me, I will look at something like the 120ST.
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Garland Coulson
Orion XT8i Dob & Celestron 80 ED on a Vixen Porta Mount Mini
Baader Hyperion 8-24mm Click Zoom & Siebert Observatory 36mm
Siebert Black Knight Binoviewers
SkyWatcher Observing Chair
Celestron Skymaster 15x70mm binos
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RussL
Music Maker
Reged: 03/18/08
Posts: 1925
Loc: Cayce, SC
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Garland, the 120ST has proved to be a decent step up from my ST80, as far as light gathering is concerned. Just remember that it isn't an ED/apo, so richfield viewing is really what it was designed for, and it excels for that.
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--Dawg, the Russell
"Akita mani yo." Observe everything as you walk. (--Lakota)
Celestron Celestar 8 Standard SCT, f10
Celestron 80mm Wide View ref., f5
Orion 120ST ref., f5
Criterion RV-6 Dynascope, Newt., f8, (c. 1962)
Sears Discoverer 60mm ref., f7, (c. 1973)
Celestron Ultima DX 10x50, 6.5 TFOV
Tasco 7x35 wide
Several mediocre eyepieces
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Hrundi
Pooh-Bah
Reged: 02/06/08
Posts: 1247
Loc: Estonia
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May I suggest that another viable alternative is to get giant binoculars? They provide even more of what you like from the refractor, and add in the benefit of binocular vision.
The con of not being able to change magnification is probably not as relevant in this situation.
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ebusinesstutor
sage
Reged: 07/01/09
Posts: 468
Loc: Nanaimo, BC, Canada
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Quote:
May I suggest that another viable alternative is to get giant binoculars? They provide even more of what you like from the refractor, and add in the benefit of binocular vision.
The con of not being able to change magnification is probably not as relevant in this situation.
I do have a pair of 15x70 Celestrons but I find it difficult make out any details in objects with them.
As I find more objects, I will try all three on them and see where I want to go with this.
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Garland Coulson
Orion XT8i Dob & Celestron 80 ED on a Vixen Porta Mount Mini
Baader Hyperion 8-24mm Click Zoom & Siebert Observatory 36mm
Siebert Black Knight Binoviewers
SkyWatcher Observing Chair
Celestron Skymaster 15x70mm binos
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Tony Flanders
Post Laureate
Reged: 05/18/06
Posts: 3469
Loc: Cambridge, MA, USA
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Quote:
One of the drawbacks with my C80ED is that I just find objects are too faint for it from my backyard.
Here's what baffles me. I do understand the attractions of observing from one's backyard, and the reluctance to leave it. But it's one thing for me here in Boston, where I have a 45-minute drive to my astronomy club's observing site, which is still heavily light-polluted.
But you're on Vancouver Island, surrounded by wilderness on all sides! In the amount of time it takes me to get to my astronomy club, you could be at a nearly pristine site, where an 80-mm refractor would show *far* more than your 8-inch scope does from your backyard. People fly thousands of miles to get to places like that.
If I were in that situation, I would *never* observe at home. Well, maybe at full Moon, but only then.
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Tony Flanders
First and foremost observing love: naked eye.
Second, binoculars.
Last but not least, telescopes.
And I sometimes dabble with cameras.
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Hrundi
Pooh-Bah
Reged: 02/06/08
Posts: 1247
Loc: Estonia
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Quote:
Quote:
May I suggest that another viable alternative is to get giant binoculars? They provide even more of what you like from the refractor, and add in the benefit of binocular vision.
The con of not being able to change magnification is probably not as relevant in this situation.
I do have a pair of 15x70 Celestrons but I find it difficult make out any details in objects with them.
As I find more objects, I will try all three on them and see where I want to go with this.
Might be worth a shot taking everything you prefer your refractor's views, and viewing it in the bino, and seeing if it comes out ahead.
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RonBurgundy
sage
Reged: 06/16/09
Posts: 271
Loc: Philadelphia
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I, too, would have to agree that the primary reason to get a refractor is its widefield abilities. That is why I got mine. It truly allows viewing of extended objects. I particularly enjoy richfield views of the Milky Way. What a sight! A fast refractor really is a larger telescope's best compliment.
Edited by RonBurgundy (11/02/09 07:38 PM)
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ebusinesstutor
sage
Reged: 07/01/09
Posts: 468
Loc: Nanaimo, BC, Canada
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Quote:
Quote:
One of the drawbacks with my C80ED is that I just find objects are too faint for it from my backyard.
Here's what baffles me. I do understand the attractions of observing from one's backyard, and the reluctance to leave it. But it's one thing for me here in Boston, where I have a 45-minute drive to my astronomy club's observing site, which is still heavily light-polluted.
But you're on Vancouver Island, surrounded by wilderness on all sides! In the amount of time it takes me to get to my astronomy club, you could be at a nearly pristine site, where an 80-mm refractor would show *far* more than your 8-inch scope does from your backyard. People fly thousands of miles to get to places like that.
If I were in that situation, I would *never* observe at home. Well, maybe at full Moon, but only then.
I just started this hobby this summer, Tony and I do hope to get to more dark sites. But the backyard has the benefits of being easy and a good place for me to learn.
While we do have darker areas here, we also have a lot of huge trees! So finding a dark site that has a good sky view, is open to the public past normal park hours, and has parking close may take some looking.
The Nanaimo Astronomy Society does have a dark sky observing site (made arrangements with a local tree farmer/sawmill), but the observers group hasn't gone out since I joined in Sept because the main person running it has had his mount out for repairs. Also with the cloudy weather we get here, the conditions may not be good on every new moon night.
I did ask if I could go to the site myself without the group and they said I could but I haven't been there yet. I will go out some time when the moon isn't up.
A lot of my nights viewing have been when the moon is in the sky so probably not worth packing up and going to a dark site in that case.
But it will happen.
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Garland Coulson
Orion XT8i Dob & Celestron 80 ED on a Vixen Porta Mount Mini
Baader Hyperion 8-24mm Click Zoom & Siebert Observatory 36mm
Siebert Black Knight Binoviewers
SkyWatcher Observing Chair
Celestron Skymaster 15x70mm binos
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Bill Weir
Pooh-Bah
Reged: 06/01/04
Posts: 1299
Loc: Metchosin (Victoria), Canada
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Garland, don't tie yourself to others to get out of the city or it may never happen. I live and observe from and area where on good nights the limiting mag is around 6.5. Think I can get many to drive the maybe 30-45 minutes to me? There are two that occasionally make the effort. I've given up asking.
Tony is right that we who live this close to very dark skies should use it more. I don't think he fully appreciates though some of the difficulties. Sure you can get away from the light but the trees around any clearing are really tall, and then there are the mountains that obscure the horizon.
My suggestion is head out the road towards Port Alberni. I have heard of some very easy to access clearcuts with fabulous skies. It gets you up and away from potential fog also. There is someone with your club who owns a 12.5" Discovery and a 20" Obsession who likes to go up that way. I can't remember his name. Track him down, he'll go out with you.
Myself, when I want a perfect sky I head towards Jordan River to this clearcut http://tinyurl.com/5x4cp2 where my SQM gives me 21.9 readings. It's 45 minutes from my home. My regular observing site is the Pearson College link on that map. It's 5 minutes from my home. SQM of 21.2.
Seriously, drive a little and your scopes will increase in aperture.
Bill
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6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar ED II
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2008, 121.
So far in 2009, 92
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Hrundi
Pooh-Bah
Reged: 02/06/08
Posts: 1247
Loc: Estonia
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The rule for going to dark sites is ask first, then go anyway.
It's nice with a group, but it's nice without one as well.
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