jgraham
Postmaster
Reged: 12/02/04
Loc: Dayton, Ohio
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Re: Using refractors for Deep Space Observing
[Re: rwiederrich]
#5192613 - 04/26/12 10:52 PM
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I use two different scopes for deepsky; a homebuilt 16.5" f/6.7 Newtonian and a 6" f/8 achro. As much as I luv my big Newt, it's the achro that I use most of the time. It's just a joy to use. I gotta be in the right mood to set up the big scope.
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gnowellsct
Postmaster
Reged: 06/24/09
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Re: Using refractors for Deep Space Observing
[Re: jgraham]
#5192664 - 04/26/12 11:25 PM
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Globs ain't so good, but there are compensations. My best fractor night was with the FS128 watching a comet in the milky way. Greg N
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Using refractors for Deep Space Observing
[Re: Alan French]
#5192907 - 04/27/12 06:01 AM Attachment (43 downloads)
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 A 5" refractor is ALOT more portable than a 30" Dobsonian!
It depends. If you can just wheel the 30" out of the garage, it could easily beat the set up time of a 5" refractor.
But, in general, you're right. It depends on how much you want the views provided by a large Dob. We don't have any really large Dobs in our club, but we have several folks with pretty large scopes (two with refractors mounted piggyback) that take some time to set up. They find it worthwhile.
Clear skies, Alan
It's true... I haul my refractors back and forth, my larger Dobs live in a garage where the skies are quite dark. Setup time is not an issue for the Dobsonians, they stay assembled.
I often use the larger scopes to locate faint targets and then use the view in the Telrad to guide me with the refractor.
Jon
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Jon_Doh
sage
Reged: 09/16/11
Loc: Area 51
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Re: Using refractors for Deep Space Observing
[Re: Jon Isaacs]
#5193257 - 04/27/12 11:53 AM
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Jon, you're lucky you have dark skies at home. For me a 30" dob would be useless. I can roll it out, but it's going to be to fairly polluted skies. Transporting it to a dark site where it could shine then obviates the purpose in having one. One day (maybe when I retire) I hope to move to a dark site and build an observatory with a huge lens telescope. Til then I'll have to get buy on smaller SCT's and refractors.
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Scott99
Carpal Tunnel
Reged: 05/10/07
Loc: New England
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Re: Using refractors for Deep Space Observing
[Re: ken hubal]
#5193261 - 04/27/12 11:54 AM
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A 5" refractor is ALOT more portable than a 30" Dobsonian!
yes, honestly "a friend's" 30-inch dob is my favorite deep-sky scope also!
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TonyF
member
Reged: 04/24/06
Loc: N. California, USA
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Re: Using refractors for Deep Space Observing
[Re: aa6ww]
#5193340 - 04/27/12 12:40 PM
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I use my 100mm refractor for deep-sky "whining"  ... Then I go to the 16" reflector as my "finder" then back to the refractor and go "Oh, there it is....." LoL!! 
Like another poster mentioned, the 16" dob on wheels is more grab-n-go out the door than any of my refractors.. I need a permanently mounted pier/GEM/observatory setup in the backyard to make it easier... Now if I only had an 8" refractor... Hummmm 
CS,
TonyF
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Mark Costello
Carpal Tunnel
Reged: 03/08/05
Loc: Matthews, NC, USA
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Re: Using refractors for Deep Space Observing
[Re: ken hubal]
#5193425 - 04/27/12 01:26 PM
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A 5" refractor is ALOT more portable than a 30" Dobsonian!
Weeeeelllll, I'm thinking that a reflector as a second scope would be more along the lines of 7"-11". When I think I can spend the money on one, it'll be my job to find a scope in that size range that would complement my 5" refractor and not so compete with it. As to larger refractors, I might be able to handle a 6" refractor but only if it was a short-tube one and at any rate it'd be a bit of a gamble. And as well as my 5" refractor is doing, I'm not all that motivated to find out. So if I get a scope bigger than 5", it'll focus light mostly or completely with mirrors.
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Pinbout
Post Laureate
Reged: 02/22/10
Loc: Montclair
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Re: Using refractors for Deep Space Observing
[Re: TonyF]
#5193465 - 04/27/12 01:58 PM
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... Now if I only had an 8" refractor... Hummmm
@ f3.75 
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Using refractors for Deep Space Observing
[Re: Mark Costello]
#5193940 - 04/27/12 07:37 PM
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A 5" refractor is ALOT more portable than a 30" Dobsonian!
Weeeeelllll, I'm thinking that a reflector as a second scope would be more along the lines of 7"-11". When I think I can spend the money on one, it'll be my job to find a scope in that size range that would complement my 5" refractor and not so compete with it. As to larger refractors, I might be able to handle a 6" refractor but only if it was a short-tube one and at any rate it'd be a bit of a gamble. And as well as my 5" refractor is doing, I'm not all that motivated to find out. So if I get a scope bigger than 5", it'll focus light mostly or completely with mirrors.
Mark:
I think you are right on target. A 10 inch would make a nice companion for your 5 inch Achromat. It is nice to have some big scopes but something between 10 and 12.5 inches is a nice size and there is plenty to see.
Jon
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coutleef
Post Laureate
Reged: 02/21/08
Loc: Saint-Donat, Québec, Canada
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Re: Using refractors for Deep Space Observing
[Re: Mark Costello]
#5193984 - 04/27/12 08:15 PM
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A 5" refractor is ALOT more portable than a 30" Dobsonian!
Weeeeelllll, I'm thinking that a reflector as a second scope would be more along the lines of 7"-11". When I think I can spend the money on one, it'll be my job to find a scope in that size range that would complement my 5" refractor and not so compete with it. As to larger refractors, I might be able to handle a 6" refractor but only if it was a short-tube one and at any rate it'd be a bit of a gamble. And as well as my 5" refractor is doing, I'm not all that motivated to find out. So if I get a scope bigger than 5", it'll focus light mostly or completely with mirrors.
you are rigth on target with that plan Mark.
A big reflector will do things your refractor cannot do and the refractor gives wide views the bigger scope cannot give.
i had ruled out big dobs initially but realized they could be carried easily with hand carts.
you have a nice scope, so take your time.
good luck in your choice
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jrbarnett
Eyepiece Hooligan
Reged: 02/28/06
Loc: Petaluma, CA
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Re: Using refractors for Deep Space Observing
[Re: Jon Isaacs]
#5194198 - 04/27/12 11:37 PM
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The refractor dilemma: dim but perfect versus bright but flawed.
Both scenarios have merit, of course, but there's something beyond compare about having a large (>5") premium refractor out under a truly dark (NELM at zenith of 7+) sky. I actually appreciate my aperture here in the 'burbs more than I do in the boons.
- Jim
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Using refractors for Deep Space Observing
[Re: jrbarnett]
#5194409 - 04/28/12 06:27 AM
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The refractor dilemma: dim but perfect versus bright but flawed.
Both scenarios have merit, of course, but there's something beyond compare about having a large (>5") premium refractor out under a truly dark (NELM at zenith of 7+) sky. I actually appreciate my aperture here in the 'burbs more than I do in the boons.
- Jim
Brightness of an extended object is not dependent upon aperture, it's a function of exit pupil... Telescopes are like camera lenses, choose the right one for the particular job at hand. A 4 inch F/5.4 is just about right for the California Nebula, not so good for 14th magnitude galaxies or globular clusters. The reverse is true of large reflectors.
Jon Isaacs
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aa6ww
sage
Reged: 10/23/11
Loc: Sacramento, Calif.
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Re: Using refractors for Deep Space Observing
[Re: galaxyman]
#5194453 - 04/28/12 07:29 AM Attachment (36 downloads)
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Do many out here use refractors for deep space observing? Over the years, I've started to move away from my largest scopes in favor or smaller more portable (somewhat) scopes for deep space hunting. These scopes almost always end up being refractors because I love the pin point stars they offer and wide field views. Of course there are still times when the skies are very dark and I take a journey to my dark site location, then I have to set up my biggest SCT, but generally, I find myself moving more toward using my refractors even for deep space observing. My 150mm and 180mm refractors are very fun to use, and still have plenty of aperture for deep space hunting. Maybe unlike most, I find myself more challenged looking for dim objects in my smaller scopes than finding the urge to want larger and larger scopes to dig out distant galaxies.
That seems to be my latest approach to this hobby.
One of my friends calls it "The less is more" mentality. Though my 180mm Refractor is quiet a beast, its still a feather weight compared to my 11 and 14" SCT's. Do others seem to enjoy this approach to astronomy also?
...Ralph in Sacramento
Hi Ralph
As Stan (Refractor6) mentioned, I only use my refractors for DSO's, and do get great results.
Jim also points out a bit why refractors do so well.
Over the past couple years I've done some hardcore galaxy observing with the 8", and in particular the ARP's.
I also notice you have an APM 7.1" f/6. Is that the APO or achro? A clubmate does have the 7.1" f/6 achro, and he gets great DSO results with that scope.
You also might want to check http://tech.groups.yahoo.com/group/deepspacewithrefractors if interested.
Karl
E.O.H.
Chesmont Astronomical Society - www.chesmontastro.org
Deep Space with Refractors - http://tech.groups.yahoo.com/group/deepspacewithrefractors
Telekit (Swayze optics) 22" F/4.5 Dob
Homemade (Parks Optics) 12.5" F/4.8 Dob
TMB/APM 8" f/9 Refractor”The Beast”. One great DEEP SKY achro
ES 6" f/6.5 achro. Good one
Celestron Omni XLT 102 refractor.
Celestron 10x60mm Binos
My 180mm TMB designed APM is an F/6 Achromat. Its all the refractor I think I could handle, unless and 8" F/6 ever showed up. They are so uncreadibly sharp refractors, I've been offered twice what I paid for it, but there's no way Id get rid of it. Id sell my TOA-130 but this ones a keeper, just as my TSA-102 is also.
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hottr6
Pooh-Bah
Reged: 06/28/09
Loc: 7,500', Magdalena Mtns, NM
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Re: Using refractors for Deep Space Observing
[Re: aa6ww]
#5194732 - 04/28/12 11:21 AM
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For my eyes, and my environment, I will take my reflector everytime for DSOs over my refractors.
Consider the Pleiades. The nebulosity is very obvious in my reflector. Even beginners can see it without being told what to look for. In my refractors, seeing the nebulosity is a stretch. Globular clusters in the big reflector are mind-blowing, then switching to my refractors there is profound disappointment.
For DSOs, I'll take every photon I can capture.
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Refractor6
Post Laureate
Reged: 10/20/04
Loc: Vancouver B.C. , Canada
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Re: Using refractors for Deep Space Observing
[Re: hottr6]
#5194774 - 04/28/12 11:50 AM
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For my eyes, and my environment, I will take my reflector everytime for DSOs over my refractors.
Consider the Pleiades. The nebulosity is very obvious in my reflector. Even beginners can see it without being told what to look for. In my refractors, seeing the nebulosity is a stretch. Globular clusters in the big reflector are mind-blowing, then switching to my refractors there is profound disappointment.
For DSOs, I'll take every photon I can capture.
I hear what you are saying BUT I remember one encounter I had in the high alpine about 10 years ago at a dark site of the Pleiades with my 6" refractor at low power with a widefield view the showed the amazing rich color of the reflection nebula in vivid detail that left even the other hardcore observers with bigger scopes around me gasping in awe at the ep.
Under the right conditions {aperture size/scope optics/ep choice/sky conditions etc..} the smaller refractors can truly rock on certain objects....globs it's no contest though in favour of the bigger well collimated reflector from my experience with views in large dobs and such. Certain fainter galaxies showed up better at higher powers in the 6" refractor though at the same location due to contrast related issues I suspect which was interesting.
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Sean Puett
Carpal Tunnel
Reged: 09/06/10
Loc: always cloudy, washington
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Re: Using refractors for Deep Space Observing
[Re: hottr6]
#5194787 - 04/28/12 11:57 AM
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I don't know about "flawed" views from reflectors other than spikes on the brightest stars. There is a slight loss of contrast from the CO but even then, the resolution makes up for it. A well cooled and properly collimated newt with a paracorr puts up some amazing planetary views. And deepsky is really no contest. I believe that you need both a large reflector and a 4"+ refractor to get the most of your session. If i had to choose one scope, it would be a 12" reflector. The only thing it can't do is widefield viewing.
Reflectors get a bad rap because they are either not well collimated, well cooled, or there is a problem with the optics. The first 2 options being the most common. A reflector owner needs to be willing to re collimate his scope after dark if it is off and not say "it is close enough" when his stars look like comets.
All that being said i spent twice as much money getting my refractor, mount, and everything needed to use it, than i did for both reflectors and my paracorr. I did this because i like the views a good refractor puts up. They can be the best scope for a given size when all the potential aberrations are controlled.
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CityAstronomer
member
Reged: 07/26/07
Loc: S. California
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Re: Using refractors for Deep Space Observing
[Re: aa6ww]
#5199329 - 04/30/12 11:34 PM
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Do many out here use refractors for deep space observing?
That is all I use here in the burbs of Los Angeles and Deep Sky Observing is my main interest. My 4 inch refractor has taken me into the NGC list as well as most of the Messier list in a white zone enviroment. I have had an 8 inch SCT and 6 in intes Mak, but sold them both for the smaller refractor. The refractor gives me the best quality view of what I can see in my backyard with the least hassle.
Sam
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northernontario
scholastic sledgehammer
Reged: 07/01/09
Loc: Porcupine, Ontario Canada
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Re: Using refractors for Deep Space Observing
[Re: CityAstronomer]
#5201058 - 05/01/12 11:24 PM
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On the brighter galaxies (M51,81,82,85 for example), my 6" f/5.9 does very well. I've had good success in Virgo.
The Veil is also very nice. Open clusters are crazy good, but Globulars are a bit tough.
M42 is also very nice with a refractor. I love looking at doubles but I guess they don't count as DSOs.
But in the end...I am addicted to my Dob.
jake
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curiosidad
sage
Reged: 06/09/11
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Re: Using refractors for Deep Space Observing
[Re: northernontario]
#5201500 - 05/02/12 10:01 AM
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And a refractor 4 "F / 5, can be a good low-medium deep sky telescope magnification?
Best
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Sasa
sage
Reged: 11/03/10
Loc: Ricany, Czech Republic
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Re: Using refractors for Deep Space Observing
[Re: curiosidad]
#5202318 - 05/02/12 05:09 PM
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I found myself observing with my refractors (ED100 and AS80) much more than with my 250mm Dobson, even DSO from my background. I like them for their contrast. Newton has quite visible issues with handling straight lights from nearby street lamps. While my refractors don't have this. More over, my Dobson is quite long (f=1600mm) and I have to stay when observing. When I observe at 300+ power (which is quite often, I like planetary nebulas), in no way I can push the telescope and simultaneously guard my eyes against street lamps. With refractors, both on alt-az (with slow control movements) or even better on my Losmandy G8, I can sit and bury the eye into the eyepiece and cover my head with hood. This helps a lot. I could detect even from my backyard, for example, very low surface brightness globular NGC5053 (near M53). I was never successful with my 250mm Dobson.
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