Aperature recommendations for visual white light scope

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
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sloth713
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Aperature recommendations for visual white light scope

Post by sloth713 »

I am looking into getting refactor and Herschel wedge for a grab and go solar set up that I plan on using for visual observing. What aperture do you folks recommend for getting great detailed views while still being easily portable?


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Re: Aperature recommendations for visual white light scope

Post by grimble_cornet »

I get very good views with a Skywatcher Equinox 80mm and a 2" Baader wedge. It can't match the resolution of my Equinox 120mm but at less than half the size and weight, it makes a great grab and go scope. When I use the 80mm for imaging, I can resolve granulation very easily in good seeing.


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Re: Aperature recommendations for visual white light scope

Post by marktownley »

Completely agree with Mike...


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Re: Aperature recommendations for visual white light scope

Post by Luke Stacy »

+1 for Equinox 80, I was very happy with a similar spec ED80 (the Celestron Onyx, F6.25, if anyone remembers those!) and I miss the extra resolution a bit. It served me very well!

I actually use a 60mm now for grab and go, but that's more to do with h-alpha as I use the same scope for both.

With my grab and go I prefer to use a 1.25 inch Herschel Wedge, for its compact size and weight, easy to tuck away inside the box. The size difference I found surprising!

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Re: Aperature recommendations for visual white light scope

Post by marktownley »

that is quite a lot smaller, well shown in the side by side...

Does that lil' Lunt have the 'built in' neutral density filter?


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Re: Aperature recommendations for visual white light scope

Post by Luke Stacy »

marktownley wrote:that is quite a lot smaller, well shown in the side by side...

Does that lil' Lunt have the 'built in' neutral density filter?
It sure does, Mark, the ND3 for visual use, and I also use it for full disc imaging at low power. I tried it with my 85mm scope and a 2x Barlow the other week and I got the feeling the details were smearing with the exposure time relatively long (I might be wrong on that, that's how it looked to my eyes), and I wondered if that is related to what people mean by "freezing the seeing" - which I've never really understood what that exactly means!

I can't see any easy way to change the Lunt 1.25's ND filter to a faster one for imaging (of course ND3 should be used for visual with this wedge).

I partly got the 1.25 as I was finding the Baader a bit of a pain to keep swapping filters and adapters around for visual and imaging E.g. with the Baader, I use an adapter that connects to my camera to do prime focus imaging (light path is too long with the original clicklock left on), but I can't then use a Barlow with it. So I have to replace the adapter with the clicklock again to switch to the 2x or 3x Barlow. Then swapsy things around for visual (change to ND3 filter, which means unscrewing clicklock, unscrewing the filters, unscrewing the ND filter from the Solar Continuum, etc.). I just found it getting a bit tedious, so I tend to use the Lunt 1.25 for visual now and full disc imaging, and the Baader mostly for 2x or 3x Barlow imaging.

Though of course the cost of having two adds up... In my ED100 I can't see a big difference visually between the two wedges, but I like the idea of imaging with a faster shutter speed with a lower ND in the Baader. Even if I am not quite sure what "freezing the seeing" means, at least a faster exposure keeps airplane (or handbag!!) transits nice and sharp :D

I get an exposure time typically of 30ms with my Quark and planes are mostly blurs now!


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Re: Aperature recommendations for visual white light scope

Post by sloth713 »

Thanks a bunch for the recommendations, 80mm definitely looks like the best size to fit my needs. Now I just have to figure which 80mm scope to get. Other than solar observing I want to use the scope for lunar observing and wide views of star fields. Also one day I would like to get into CaK or CaH observing and I was wondering do I have to worry about any optical coatings that could block the near ultraviolet that various telescope manufactures may use?

So far I have been looking at 3 telescopes. (I have had no first hand experience with these scopes, I am just going of what I have read on various astronomy forums).
1.Lunt Engineering 80mm f/7 ED Doublet: It is the least expensive and come with a case. Though with accessories it will cost the same as the Sky-Watcher 80mm (but I like the idea of hand picking the exact accessories I want).
2.Sky-Watcher Pro 80mm f/7.5 ED APO Doublet: It supposedly has better ED glass and color correction than the Lunt scope. Also it comes with all the accessories and has a hard case that will fit the telescope and accessories. But apparently the focuser is not the best.
3.Explore Scientific 80mm f/6 Essential Series Triplet: On paper has the best optics and has the fastest focal ratio so that I can get the widest field of views. But it doesn't come with case and I don't know if a triplet is really worth the extra cash for visual observing.


Any thoughts and opinions on these three scopes would be greatly appreciated. Also any other scope recommendations would welcome. Thanks again everyone.


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Re: Aperature recommendations for visual white light scope

Post by Merlin66 »

I've been using the SW ED80 with various solar filters for the past seven years.
No issues, no drama.
The standard focuser is OK, but you need to add at least the SW focuser motor.


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Re: Aperature recommendations for visual white light scope

Post by marktownley »

sloth713 wrote:Thanks a bunch for the recommendations, 80mm definitely looks like the best size to fit my needs. Now I just have to figure which 80mm scope to get. Other than solar observing I want to use the scope for lunar observing and wide views of star fields. Also one day I would like to get into CaK or CaH observing and I was wondering do I have to worry about any optical coatings that could block the near ultraviolet that various telescope manufactures may use?

So far I have been looking at 3 telescopes. (I have had no first hand experience with these scopes, I am just going of what I have read on various astronomy forums).
1.Lunt Engineering 80mm f/7 ED Doublet: It is the least expensive and come with a case. Though with accessories it will cost the same as the Sky-Watcher 80mm (but I like the idea of hand picking the exact accessories I want).
2.Sky-Watcher Pro 80mm f/7.5 ED APO Doublet: It supposedly has better ED glass and color correction than the Lunt scope. Also it comes with all the accessories and has a hard case that will fit the telescope and accessories. But apparently the focuser is not the best.
3.Explore Scientific 80mm f/6 Essential Series Triplet: On paper has the best optics and has the fastest focal ratio so that I can get the widest field of views. But it doesn't come with case and I don't know if a triplet is really worth the extra cash for visual observing.


Any thoughts and opinions on these three scopes would be greatly appreciated. Also any other scope recommendations would welcome. Thanks again everyone.
I will be buying a SW 80mm f7.5 within the next two weeks.

Interesting comment about the ES having the best optics, if you're wanting to get into CaK at some point the faster the focal ratio the less contrast you will have.


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Re: Aperature recommendations for visual white light scope

Post by swisswalter »

Hi Sloth713

I would go with the LUNT system


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Re: Aperature recommendations for visual white light scope

Post by SMS »

I would vote for the ED80 too. I've been using the Orion f7.5 version for years for astronomy and wildlife photography. It's a heck of a good scope for relatively little money. The scope that I also use with my Herschel wedge is a Celestron 102 f9.8. Oceanside Photo was selling the OTA for $59 so I couldn't resist. The OTA is long but it's very light and the optics are far better than price would suggest. The stock focuser is an R&P but it isn't bad at all for visual use.


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Re: Aperature recommendations for visual white light scope

Post by grimble_cornet »

I use the SW Equinox 80 for Solar, Lunar and deep sky imaging and it works well for all of these.
A few things to bear in mind:

Although some reviews say that the Equinox and Sky Watcher Pro have the same optics - they don't!
The Equinox 80 is f6.25 and the Pro is f7.5 - this may or may not matter to you but they do give significantly different fov. A friend of mine has the Pro and we often image the same target using the same Atik cameras - and get totally different results!
If you don't already use it, download ccdCalc which will allow you to compare fov with different scope/camera combinations on lots of targets - for free!

The Equinox works very well for white light and performs quite well with my DayStar Quark for Ha. Based on my experiments with a range of refractors and reports from other users, the Pro with its higher f7.5 should work even better than the f6.25 Equinox with the Quark (which, I guess, is why Mark is getting one).
If you think you will go for CaK using a Lunt CaK unit then take care! This unit needs to go about 90mm into the telescope focuser tube BUT the Equinox has a step about 50mm in which stops the unit and prevents it reaching focus. I'm not sure if the Pro uses the same focuser (they look the same) but worth thinking about? It obviously works with the Lunt 60 (they come as a kit) and I assume with the Lunt 80?

The Equinox/Skywatcher focuser is OK but, as Merlin said, it can be improved greatly by adding the electric focus motor for about £60.
I have a Lunt 60mm (came with the CaK unit) and it is very well built. However - although the standard dual speed focuser feels OK and works well with the CaK unit............ it can't cope with the heavy Baader ceramic wedge without slipping at high elevations. My Lunt 100 has a Feathertouch focuser which is just superb (thanks for talking me into getting that Walter) but does add significantly to the cost.
Luke's report on the Baader 2" wedge matches my experience fairly well. I use a low-profile T-1.25" adaptor and can JUST reach focus with/without Barlows etc. when using the Equinox 80, Equinox 120 and Lunt 60.
Several refractors (including my Tal 100) will not come anywhere near focus with the Baader 2" wedge as the light path is significantly longer than with a normal 2" diagonal.

If you can afford a better focuser - and want to use it for white, CaK and Ha - I think the Lunt would be a good choice. Based on my 60 and 100 models; the build quality is superb, it will work well for all solar observing and imaging - plus the customer service is legendary.

Hope some of this helps?


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Re: Aperature recommendations for visual white light scope

Post by marktownley »

grimble_cornet wrote:the Pro with its higher f7.5 should work even better than the f6.25 Equinox with the Quark (which, I guess, is why Mark is getting one).
Exactly right Sir ;)


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