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Sweeping through the Milky Way

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#1 JimP

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Posted 18 October 2018 - 05:08 PM

What refractor would you recommend for visually sweeping through the Milky Way only. It seems the smaller the aperture the wider the field of view which is a plus or, the larger the aperture the greater the light gathering power resulting in more stars visible which is also a plus.
80 F/6, 102F/6, 130 etc.
My skies are Bortle 4
I have astigmatism so I use a Dioptrix. Even with the Dioptrix it is best to stay around a 17mm up to a maximum 21mm Ethos.
Your thoughts?

#2 The Ardent

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Posted 18 October 2018 - 05:13 PM

Use a 2” Amici prism so the scope view correlates with naked eye and binoculars view.
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#3 jay.i

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Posted 18 October 2018 - 05:18 PM

An NP-101 would be hard to beat. 101mm at f/5.4 with a flat field would be pretty ideal for widefield sweeping I think! I know Jon Isaacs likes his for this. If you don't mind going a little more narrow and a lot more expensive, an NP-127 or FSQ-130, both with flat fields, would be very very sweet.


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#4 Jon Isaacs

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Posted 18 October 2018 - 05:42 PM

What refractor would you recommend for visually sweeping through the Milky Way only. It seems the smaller the aperture the wider the field of view which is a plus or, the larger the aperture the greater the light gathering power resulting in more stars visible which is also a plus.
80 F/6, 102F/6, 130 etc.
My skies are Bortle 4
I have astigmatism so I use a Dioptrix. Even with the Dioptrix it is best to stay around a 17mm up to a maximum 21mm Ethos.
Your thoughts?

 

How much are you willing to spend?   At one end there's an ST-80 fitted with a 2 inch focuser that's a couple of hundred dollars.  At the other end, there's the NP-101 which is $2000+ used.  With the 21mm Ethos, the ST-80 will provide a 5.2 degree field of view at 19x with a 4.2mm exit pupil and quite a bit of field curvature, stars won't be in focus across the field of view.

 

With the NP-101, the 21mm Ethos provides a 3.8 degree TFoV at 26x with a 3.9mm exit pupil and the stars will be in focus across the field of view.  The correction for field curvature is a big part of what costs.. 

 

Jon


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#5 CSG

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Posted 18 October 2018 - 05:49 PM

I use my old Pronto with the TV 2" diagonal and 35mm Pan ep.  If you can swing an NP-101 and want something of that size, it's hard to beat.  Best view I ever recall of the Double Cluster was with my former NP.  Sold it because I liked using the smaller scope in spite of its limitations.  The TV-76 and TV-85 would be a couple other good choices.  I'm hoping my incoming Stowaway will trump them all.


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#6 NC Startrekker

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Posted 18 October 2018 - 07:08 PM

For wide-field sweeping, I can't think of any better options than the Tele Vue NP-101 or NP-127. At f/5.4 and f/5.2 respectively, they afford some of the lowest focal ratios available in apos of their aperture. This means widest possible FOV with any given eyepiece. Their Petzel lens design also ensure virtually flat fields across the field of view. No nausea from field curvature as you sweep along the star fields. Only real negative is cost but quite good deals can be found with patience on the used market. 


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#7 aa6ww

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Posted 18 October 2018 - 07:26 PM

I think the Orion 120ST is a very potent sky sweeper without being so big that you wont want to use it.

 

If you want to keep things light, the Astro Tech 102ED with the beautiful Aston Martin grey highlights is a light weight 9 pound OTA that would work very well on even a small Alt-Az mount.

 

Once you get about 3 degs of actual field of view, everything after that is just icing on the cake. Very few objects need more field of view then that, but there are a few. The Entire veil nebula comes to mine and the North American nebula also. Sometimes wanting to see the entire sword or belt in Orion in one field of view is very nice also. Or Kimble's cascade in one field of view. I've seen all of these in one field of view in an Orion ST-80 with a 24mm 68 deg eyepiece, so it doesn't take much to get those wide field sweeps.

Under dark skies, Markarians chain is an absolute favorite  for wide field sweeping of the skies in Virgo. 

 

The choices seem endless. It more so, depends on your budget and how large and heavy a scope you are looking for.

 

Big Binos are very nice also. Nothing beats using two eyes in a tripod mounted set of binoculars with interchangeable eyepieces. Even the 70mm right angle binoculars seem very nice for sky sweeping if you have interchangeable eyepieces.

 

...Ralph


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#8 Tyson M

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Posted 18 October 2018 - 08:26 PM

Hard question to answer, as there was so many good choices listed and this is all subjective and depends on your budget.  I LOVE sweeping the MW with my 80mm F7.5 scope and a 32mm masuyama. And I like sweeping up the MW even more with my TS152mm F5.9 achro with 31mm nager.

 

The 80mm has more field of view but the 152 has much more stars. 

 

With the right combination of eyepiece you can get fairly generous fields with even long focus refractors.


Edited by Tyson M, 18 October 2018 - 08:26 PM.

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#9 Ryan555_1

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Posted 18 October 2018 - 11:22 PM

For cheaper but immersive views, get a st80 with a 2" Focuser. There are better options for about 10x the cost.

#10 CHASLX200

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Posted 19 October 2018 - 05:20 AM

I had a Meade 5000 80mm APO that was a killer sweeper. Just slap in a 21mm Ethos and enjoy.


Edited by CHASLX200, 19 October 2018 - 05:20 AM.


#11 clearwaterdave

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Posted 19 October 2018 - 06:45 AM

Cruising the Mother Cluster is one of my favorite astro views.,and I do it every night I'm out with one instrument or another.,

 With what I have the best views of the MW are with the ar127 with the Baader 36mm.,3*-23x.,Got Stars.,



#12 bobhen

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Posted 19 October 2018 - 07:41 AM

I live just outside Philadelphia, PA with a “Bortle 7” sky and in heavy light pollution.

 

I use a very inexpensive Celestron/Synta 102mm F5 achromatic refractor. BUT I have added a somewhat expensive Night Vision Image Intensifier, a couple of filters (Ha and Pass) a .7 reducer is used sometimes getting the refractor down to F3.5 and a simple alt/az mount.

 

With the above system from my “Bortle 7” sky, I have “easily” seen: the Horsehead Nebula, Barnard’s Loop, Helix Nebula, California Nebula, North American Nebula, Crescent Nebula along with many other nebula “too numerous” to mention here that were once considered impossible visually especially from a location like mine.

 

In addition to nebula wide swaths of the Milky Way are seen along with dark nebula and numerous clusters. The views remind me of the views I had using the same scope but without the Intensifier at Bryce Canyon, except the Intensifier views show more.

 

The downsides to adding an intensifier are: expense, monochromatic views only (with a very slight gray/green or very slight gray/bluish tint , some scintillation depending on gain control.

 

The upsides, in addition to the unbelievable views, are: Real time viewing, as light and as easy to use as an eyepiece, no cables/power etc., can use on an alt/az mount.

 

I’ve been using an intensifier for 2.5 years and since that time I rarely use a glass eyepiece for deep sky viewing.

 

If you want to learn more about Night Vision HERE is a link.

 

Below is the 102mm refractor and Intensifier system that I use.

 

Bob

 

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#13 MalVeauX

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Posted 19 October 2018 - 07:53 AM

Heya,

 

I would go for aperture and wide field, go for a rich wide field scope.

 

I also like the ST80 (80mm aperture, 400mm F5) refractor with a 2" focuser for this to get really, really wide field (up to 6 degrees is easily achieved), but with that 80mm aperture you still pull in enough light to see lots of feint stars, which makes for a really rich field view.

 

You could also look at the ST120 (120mm aperture, 600mm F5), as it can also hit 4 degrees with a 2" eyepiece and has a 120mm aperture, so it just gobbles up lots of light! This would be an ideal low power sweeper for the Milky Way and Messiers in general.

 

They're light enough to ride humble mounts, or camera tripods too.

 

++++++++++++++++++++++

 

I'm in a green zone, pretty dark skies, I use the ST80 for my sweeper. It's crazy how many stars I get under a dark sky. If it weren't for my sky, I'd use larger aperture.

 

ST80 with 2" Antares single speed crayford focuser

Agena SWA 38mm 70 degree FOV eyepiece (2").

Over 6 degree FOV. I get lost in space.

Twilight Nano mount

 

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38811412715_d5a6369b12_c.jpg

 

39000094144_4227c4c5c4_c.jpg

 

Very best,


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#14 mich_al

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Posted 19 October 2018 - 10:19 AM


Big Binos are very nice also. Nothing beats using two eyes in a tripod mounted set of binoculars with interchangeable eyepieces. Even the 70mm right angle binoculars seem very nice for sky sweeping if you have interchangeable eyepieces.

...Ralph


I'll second the big binos idea. This Summer I mounted a pair on a Zero Gravity chair that is on a lazy susan swivel. By far the best views scanning the Milky Way I've ever had.

#15 Cliff C

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Posted 19 October 2018 - 01:58 PM

Jim,

Like CSG I usually sweep the Milky Way with my Pronto but with a 1.25" diagonal for better balancing. The two eyepieces that I wind up using the most are a 20mm Televue plossl and 32mm Televue plossl. The 32mm gives me about a 3 degree field of view. The nicce thing about these short scopes (500mm or less) is that swinging them from say a 45 degree elevation to Zenith does not change the eyepiece height that much. Even though I have a 130mm f/6 scope and do use it for Milky Way sweeping, the Pronto is just so dang easy to set up and use.

Cliff


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#16 contrailmaker

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Posted 19 October 2018 - 09:56 PM

Cruising the MW was my favorite kind of observing when I lived under Bortle 3 skies. The Orion 120 ST was great for that but I wanted to binoview so I replaced it with 25x100 binoculars and never went back. If I lived under the same conditions now I’d get 80 or 100 mm binoculars that allow for interchangeable eyepieces. Two eyes are way better than one.

 

CM


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#17 Bomber Bob

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Posted 19 October 2018 - 10:11 PM

For Milky Way sweeping, I have lots of options...

 

-- My favorite is this 4" F5 that I built using a vintage 1970s Jaegers achromat:

 

Jaegers 4 F5 RFT on Polaris-Eagle.jpg

 

-- Vintage 5" F5 triplet made by an unknown ATM using a commercial OTA.

 

-- Vintage 6" F4 Edmund Newtonian.

 

-- 1995 Vixen FL80S F8 fluorite.

 

-- APM 152 F8 ED with bino-viewer -- "It's full of stars!"

 

-- Vintage Selsi 20x60 binoculars.


Edited by Bomber Bob, 20 October 2018 - 07:09 AM.

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#18 jeremiah2229

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Posted 19 October 2018 - 11:29 PM

As crazy as it might sound I had some premium nights in the southern Milky Way this season using a C8 + 6.3 r/c + Pan 35 (~1.88° at 36x) and the memories will last until I leave this earth. Eight inches of light gathering and M24 was a treat, very special.  waytogo.gif

 

 

Peace...


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#19 Sketcher

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Posted 19 October 2018 - 11:55 PM

What refractor would you recommend for visually sweeping through the Milky Way only.

Any 4 to 6 inch short-focus refractor would be great.  Having a 2-inch focuser would be preferred over a 1.25-inch.  I tend to prefer a 4 to 5mm exit-pupil for such purposes; but others may have other preferences.

 

There's enough variety in the Milky Way that a 4-incher would be better for some objects, a 5-incher for others, and a 6-incher for still others.  So, IMO, any aperture in that range would be as good as any other.


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#20 Doug D.

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Posted 20 October 2018 - 06:54 AM

I use a 105 f/5.8 and a 21 Ethos for sweeps - near ideal for the purpose but field could be flatter.  Binoculars would be the  must have, go anywhere alternative.


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#21 junomike

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Posted 20 October 2018 - 07:02 AM

Cruising the MW was my favorite kind of observing when I lived under Bortle 3 skies. The Orion 120 ST was great for that but I wanted to binoview so I replaced it with 25x100 binoculars and never went back. If I lived under the same conditions now I’d get 80 or 100 mm binoculars that allow for interchangeable eyepieces. Two eyes are way better than one.

 

CM

This is my experience also as I currently use an APM 100 (45° Semi Apo) as my main sweeper although I have in the past enjoyed using a 120 F5 and 130mm F6 and even my AT12 F4.


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#22 Jim Davenport

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Posted 20 October 2018 - 10:18 AM

I'm love my Orion 120ST, with a ES 30/82 eyepiece. Just get lost in the summer milky way.

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Edited by Jim Davenport, 20 October 2018 - 10:19 AM.

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#23 25585

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Posted 20 October 2018 - 10:34 AM

My TV 500mm F5 Genesis. 9x with a 55mm Plossl, then up with my 48 Brandon, 35 Panoptic, 20 Orion LHD 80 and 12 ES 92.

 

Use an UHC filter for nebulas.

 

An Altair 152mm Starwave F5.9 might be the ultimate rich field refractor. 


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#24 Tamiji Homma

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Posted 20 October 2018 - 11:03 AM

Here is my star field sweepers.

 

From my backyard, Pentax 100 SDUF-II with ES9-100 shows the most impressive star field.  

From darker site, Nikon WX 10x50 is the most impressive.

 

Pentax 100 SDUF-II f/4, ES9-120, 44x, 3.2 degrees TFOV:

large.jpg

 

The same scope with Nikon NAV HW 17, 23.5x, 4.3 degrees TFOV:

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TMB 92SS f/5.5 with FT 3.2" focuser, 3" diagonal, ES30-100, 16.9x, 5.8 degrees TFOV, waiting for first light.

large.jpg

 

Nikon WX 10x50, 10x, 9 degrees TFOV:

large.jpg

 

For night walk, I take Miyauchi Binon 5x32w:

large.jpg

 

Tammy


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#25 balu01

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Posted 20 October 2018 - 02:02 PM

Would an FSQ85 qualify for this as a good pick?
Having a good back focus being able to accommodate bono’s and 2” ep’s ?


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