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What is the difference between a William Optics 61mm Refractor and a Orion ST80 80mm Refractor?

Refractor Optics Equipment
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#1 Aman Dude

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Posted 18 September 2021 - 11:33 AM

I have had the Orion ST80 80mm Refractor Telescope for a while now, but I eventually want to upgrade to a better one. When I look at the refractor telescopes on optcorp.com, most of the ones for astrophotography are by William Optics. The point is that you only get 61mm of aperture on the WO for $590, and 80mm on the Orion ST80 for only $130? 

 

What I am not understanding is why the WO is more expensive than the other one considering it only has 61mm vs 80mm? Although, I have heard it has better quality lenses.

 

My main question is, is it worth it to upgrade to a WO for astrophotography that is only 61mm from my 80mm Orion ST80? And what some differences between them that make them so different? I also don't think spending $1010 on an 81mm WO is a very good option, that is, unless a see a more valuable reason.

 

Thanks!



#2 DJL

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Posted 18 September 2021 - 11:45 AM

What is it you want to improve about the ST80?

 

Check out Ed Ting's thoughts here: https://www.scoperev...m/page1.html#5 


Edited by DJL, 18 September 2021 - 11:51 AM.

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#3 matt_astro_tx

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Posted 18 September 2021 - 11:45 AM

First, the Orion is a budget scope.  So yes, upgrading to a higher quality instrument will yield much better image quality and, depending on your use (i.e. astrophotography) will pay big dividends.

 

Second, the ST80 has 400mm of focal length.  The WO 61mm has 360mm of focal length.  So as far as how big a difference in the image scale you'll see, they're practically the same scope in that regard.

 

Lastly, while William Optics is highly regarded, given the scope you're looking to upgrade from, I would recommend looking at Astro Tech on the Astronomics web site.  You can get the AT60ED for $399 and it is an analogue of the WO 61mm.  I have one and am a very happy user.  (I'm also an active Astro Tech endorser on here because I really do feel the quality for the price is worth it!)  (No affiliation with Astro Tech, just a satisfied customer.)

 

They also have the AT80ED for $399 and the AT80EDT (a triplet - best option if you're doing AP) for $849.  Great savings compared to WO at OPT.


Edited by matt_astro_tx, 18 September 2021 - 11:47 AM.

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#4 Ken Sturrock

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Posted 18 September 2021 - 11:57 AM

My main question is, is it worth it to upgrade to a WO for astrophotography that is only 61mm from my 80mm Orion ST80?


I'm going to move this since you'll probably get better answers in an actual AP forum versus one explicitly marked as "not for AP".


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#5 vtornado

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Posted 18 September 2021 - 12:06 PM

I don't do AP, but the Williams optical scope is an APO, and has a more precise focuser.

An APO greatly reduces chromatic abberation found in the ST80.  A camera is more sensitive to it than your eye.

I am not an optical expert, but compared to my Orion ED 80 telescope, the Short tube has more

optical abberations in addition to CA.   I can  see it when doing high power lunar.

 

I'm not dissing the ST80 it has 80mm of aperture and does low - medium power wide field visual sweeping

very well.   It is not a scope for AP or a scope for high power. For Visual the Williams 61 is probably inferior

due to the aperture loss.

 

VT.


Edited by vtornado, 18 September 2021 - 12:35 PM.


#6 rgsalinger

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Posted 18 September 2021 - 12:08 PM

Yes but you have to be able to capture data and process it to see the differences. No two element refractor can compete when it comes to chromatic aberration with a well designed 3 element refractor. That's why virutally every refractor who's intended use is photography has three elements. In addition, the imaging circle is going to be bigger - see if there a specification somewhere for the scopes.

 

I don't own either the WO81 or the AT80. I can tell you that my WO71 which was about a grand 5 years ago is a terrific wide field scope. I think that a grand USD is about the cheapest price point for a wide field refractor that will give you years of satisfaction.

 

Rgrds-Ross


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#7 idclimber

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Posted 18 September 2021 - 12:38 PM

You do not list the rest of your AP equipment. As such this question can not be fully answered. If the weak link is in fact your scope, then upgrading may make some sense. I would guess though that you would be better off looking at other components of your system like the mount or camera. 



#8 DJL

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Posted 18 September 2021 - 12:54 PM

This may also be helpful: http://uncle-rods.bl...ese-scopes.html



#9 DJL

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Posted 18 September 2021 - 12:59 PM

Team William Optics here. I chose the GT81 over the ZS version due to triplet vs doublet. I have been very happy with it and miss it a lot when I have to use different optics for wider (Spaghetti Nebula) or narrower (planets) FoV targets.



#10 OldManSky

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Posted 18 September 2021 - 01:36 PM

The ST-80 is an achromat, meaning it uses lenses that don’t correct very well for chromatic aberrations, and different colors come to focus at different points, resulting in color fringing. The tube and focuser are also made of low-cost materials. The ZS-61 uses more expensive glass (one of which is FPL-53), which provides significantly better color correction. The tube and focuser and rings are also of significantly higher quality than the Orion, making for a much better platform for imaging.

That is why the cost difference.


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#11 sevenofnine

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Posted 18 September 2021 - 03:32 PM

It sounds like you are thinking about AP at some point? The Celestron ST-80 is a classic achromatic refractor that has lots of uses in this hobby. As a beginners telescope, it offers wide views of the night sky and is easy to locate objects. However, it will show lots of false color on bright objects. To optically correct for those colors is very expensive. I just purchased a AT-80ED for $400 and it is the same size lens as the ST-80. Plus it's considered a very good deal for an 80mm refractor with ED glass. This kind of glass produces much better astro photos than a typical achromat.

 

Just in general, astrophotography is more about the mount than it is about the scope. Buy a really good mount and the rest will fall in place...eventually. The starting point for the necessary gear is $2000 and up. Many say "Way Up!" There's also a very steep learning curve. So there's that to consider. Best of luck to you, what ever you do! waytogo.gif



#12 gzljh96

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Posted 19 September 2021 - 10:30 AM

The ST80 is an achromatic doublet, meaning it has two pieces of glass and it doesn’t correct chromatic aberrations (and other optical aberrations) as well. In practice, it means the image will have a purple/red aura around bright edges, and the image will not be as sharp. This is more noticeable in AP than visually, but it is there.

The WO ZS-61 is an ED apochromatic doublet, meaning it corrects false colour better than an achromatic telescope through the use of expensive glass. It is also better built mechanically, with a better focuser, etc. The APO doublet would not eliminate false colour entirely, which is why their GT series exist — those are APO triplets with another piece of glass give better optical performance. Finally, WO also has the RedCat series and the discontinued Star 71, which use a Petzval design with 4 piece of glass and a 5-element design respectively. Those scopes are mostly aimed at AP and they provide a very sharp, flat image out of the box, though they can also be used visually.

For your purpose, visually the Orion provides a brighter image, while the ZS61 provides a sharper, mostly false-colour free one. For AP, as others mentioned, it’s more important to get a good mount. Even the ST80 can produce some good images if you know how to process them. However, if you are looking for an upgrade, and only looking for refractors, an ED doublet like the ZS61 or the cheaper AT-61 is the logical way to go.

Skywatcher also produces pretty decent ED doublets. They are heavier and have worse built quality than some other scopes, but dollar for dollar they provide more aperture and from what I heard, the optics are pretty good.
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#13 Aman Dude

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Posted 19 September 2021 - 09:03 PM

You do not list the rest of your AP equipment. As such this question can not be fully answered. If the weak link is in fact your scope, then upgrading may make some sense. I would guess though that you would be better off looking at other components of your system like the mount or camera. 

I almost have the ZWO ASI178MC 6.4 MP CMOS Color Astronomy Camera with USB 3.0# ASI178MC as my AP camera, as it is still shipping. I am currently using my phone for AP. I have a camera tripod as a mount because the telescope mounts I looked at just don't fit my budget. That is pretty much it as far as extras go (I know, a very bad and cheap setup).


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#14 unimatrix0

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Posted 19 September 2021 - 09:39 PM

First of all the telescope prices are jacked up lately. Despite what others would tell you the low level William Optics (and the Z61 is the cheapest) are not as good as the upper models.  I , personally - despite popular opinion- would not buy another William Optics product until they sort out their quality inspection routine. I have a very bad experience with them (focuser fell apart, pinched optics, flattener doesn't flatten   -- all this and the telescope is 8 months old) 
It's definetely not worth $590.  Just 8 months ago it was $430.  Also it needs a dedicated flattener (Flat61), which is another $200 if you want to image with it.  Now you are looking at $800 plus tax.  Now you are in the Redcat territory as far as price and there are some triplet APOs  too.

The redcat needs nothing, it's a petzval design and the flattener is essentially built in and will give you a flat field, it's light and works on the lightest mounts and trackers just fine. 

 

There isn't a lot you can do from a camera tripod, not sure you should spend $800 on a telescope for astrophotography, you should think about a tracker first and either use a DSLR or get a small telescope like the Redcat. There isn't a lot of telescopes that beat the Redcat, as far as a ready to go, full package.   Also the Zenithstar 61 +flattener+camera isn't that light, just ask me, I have one. my modified AZGTI mount sounds like getting tortured by it when I attach it. 

 

Once you think you could afford a a go-to mount, then you can start looking into larger telescopes that happened to be more expensive (and heavier also).   


Edited by unimatrix0, 19 September 2021 - 09:47 PM.


#15 idclimber

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Posted 19 September 2021 - 11:38 PM

I almost have the ZWO ASI178MC 6.4 MP CMOS Color Astronomy Camera with USB 3.0# ASI178MC as my AP camera, as it is still shipping. I am currently using my phone for AP. I have a camera tripod as a mount because the telescope mounts I looked at just don't fit my budget. That is pretty much it as far as extras go (I know, a very bad and cheap setup).

Without an equatorial mount the differences between these scopes is irrelevant for AP.

 

If you already have a 60mm scope and are considering an 80 do not consider a camera tracker.



#16 17.5Dob

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Posted 20 September 2021 - 02:52 AM

Without an equatorial mount the differences between these scopes is irrelevant for AP.

 

If you already have a 60mm scope and are considering an 80 do not consider a camera tracker.

lol.giflol.giflol.giflol.gif

Even a rudimentary eye can tell the difference between a cheap achromatic and a reasonable ED doublet. ...There is no contest. This is a case where mounts make no difference..

And why WO....? I would suggest anything other than them...

















 


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