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Buying a Lunt 50mm --> Should I double-stack?

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#26 Bokchoy Ninja

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Posted 31 May 2020 - 01:10 PM

And if I get the 50mm double stack filter to put on the 60mm lunt, does that completely negate the benefits of having a 60mm model? Or is it still better for imaging purposes?

#27 MalVeauX

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Posted 31 May 2020 - 01:14 PM

And if I get the 50mm double stack filter to put on the 60mm lunt, does that completely negate the benefits of having a 60mm model? Or is it still better for imaging purposes?

Heya,

 

Pressure tuning is considered a little better, it should provide a bit more uniformity when tuning. But that said, I would not consider a tilt-tuned version a deal breaker at all, they're very good still, and lots of examples around here showing excellent uniformity still.

 

Putting a 50mm double stack on the 60mm indeed negates the resolution of the 60mm aperture; as it masks the overall aperture to 50mm; but it is not negating the better 60mm's etalon and sweet spot properties. While the 50mm double stack option is there, and less expensive, I would not suggest it. I would suggest you pony up when its time and get the full on 60mm double stack to retain the resolution of the 60mm aperture potential and the better etalon series potential. You're also still getting the better instrument with the 60 as a base instrument with the focuser and all that.

 

Very best,


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#28 Bokchoy Ninja

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Posted 31 May 2020 - 01:16 PM

Heya,

Pressure tuning is considered a little better, it should provide a bit more uniformity when tuning. But that said, I would not consider a tilt-tuned version a deal breaker at all, they're very good still, and lots of examples around here showing excellent uniformity still.

Putting a 50mm double stack on the 60mm indeed negates the resolution of the 60mm aperture; as it masks the overall aperture to 50mm; but it is not negating the better 60mm's etalon and sweet spot properties. While the 50mm double stack option is there, and less expensive, I would not suggest it. I would suggest you pony up when its time and get the full on 60mm double stack to retain the resolution of the 60mm aperture potential and the better etalon series potential. You're also still getting the better instrument with the 60 as a base instrument with the focuser and all that.

Very best,



Thanks for the advice!

Is a few hundred bucks better spent toward pressure tuning or toward saving for a double stack filter?

#29 George9

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Posted 31 May 2020 - 01:42 PM

I have heard many good things about the tilt version, that I don't think you can go wrong either way. I am partial to the pressure tune because I find it easy to look at structure off band in red or blue. The sweet spot is large in the PT. But perhaps some have used both and can comment. I have only looked through the LS60 PT. George



#30 MalVeauX

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Posted 31 May 2020 - 01:43 PM

Thanks for the advice!

Is a few hundred bucks better spent toward pressure tuning or toward saving for a double stack filter?

I can't really give a supported answer to that one. There are plenty of tilt-tuned instruments with a double stack posting on here all the time, and elsewhere, with great results. It depends just how much of a difference it is to you. Personally, I do think the latest modular Lunt models with good ED doublets as the base scope are worth the extra money because modular allows you to do more with different wavelengths and different uses. And I think pressure tuning does have a slightly better result than tilt tuning does, which is why Lunt went that direction ultimately (uniformity and sweet spot shape/size). I think getting the best instrument up front you possibly can, with future upgrades available later is the better thing to do. Rather than get a slightly inferior instrument to allow faster upgrades later. It's a very personal thing and up to you. Personally I would get the better scope up front with better etalon and better tuning system if possible up front and save to double stack it later on. Budget is a reality of course and few hundred can really make a difference, but if the goal is to get it right as well as possible and get the most for your money, getting a newer one with the best options right now is likely best and it will be supported too.

 

Very best,


Edited by MalVeauX, 31 May 2020 - 01:58 PM.


#31 Bokchoy Ninja

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Posted 31 May 2020 - 01:57 PM

Thanks for the advice, all. Will update with what I buy

#32 Gregory Gross

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Posted 31 May 2020 - 02:01 PM

As with all things that one hears about but has little if any practical experience with, I would say that I've heard adding a tilt-tuned double-stack module onto a scope with a tilt-tuned internal etalon is not as optimal as adding the tilt DS module onto a pressure tuned scope. The main concern here is having to contend with two etalon types that both have a tendency towards banding in terms of how the sweet spot presents itself. When you add a tilt-tuned DS module onto a scope with a pressure-tuned primary etalon, you get the benefits of a more circular sweet spot and minimize the effects of the banding that the DS module adds.

I would appreciate it if others who own and have more experience with the tilt-tilt combo would comment one way or another on this thread.

I understand that Lunt has discontinued their tilt-tuned 60mm scopes, so if the intent is to buy new, that option may no longer be available at least through Lunt. You may have to buy used or find a retailer with remaining stock of the older tilt-tuned scopes.

But if it were me, I'd be targeting the pressure-tuned scopes anyway. As an owner of a 60mm pressure-tuned Lunt with 60mm tilt-tuned DS module, I really like what that combo offers. I think the only downside to pressure tuning that I can think of is the O-rings inside the tuning cylinder wearing out, but those are easily replaced.

In another thread on this forum, I posted links to some worthwhile and informative reading on the topic of pressure tuning.



#33 Gregory Gross

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Posted 31 May 2020 - 02:39 PM

At risk of tooting my own horn too much, I'd also add that I wrote more about my experience double-stacking my 60mm Lunt here.
 
I also wanted to note that I observed an uptick in reddish background glare when I upgraded from my 50/50 DS'ed Lunt to my 60/60mm DS'ed Lunt, something I discussed in this thread. The addition of a simple and inexpensive ND 0.3 filter as I discuss later in that thread greatly reduced that glare. That glare was the only negative thing that I observed when I got my 60mm Lunt, although other 60mm Lunt owners don't seem to have had the same experience (file this under "your mileage may vary").

 

The increase in the size of the sweet spot and the increase in resolution and image brightness both made the upgrade very worthwhile at the end of the day. So if you're thinking about going straight for the 60mm route, I think you're setting yourself up to be in really great shape from the get go.



#34 rigel123

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Posted 31 May 2020 - 08:23 PM


I would appreciate it if others who own and have more experience with the tilt-tilt combo would comment one way or another on this thread.

 

Not sure if I am the only one on here with the tilt-tilt combo Lunt 60 and I can’t compare to a PT-tilt combo, but I like the views I get as well as the images that I can capture with the tilt-tilt set up.  The sweet spot is large enough to cover the full disk and I have a very dark background.  


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#35 Bokchoy Ninja

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Posted 01 June 2020 - 09:03 AM

Thanks again guys.

 

One more... with the Lunt 60, is imaging as simple as replacing the eyepiece with an appropriately sized CMOS and adjusting the focuser until focus is reached? Or do I need to get "creative"?



#36 rigel123

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Posted 01 June 2020 - 09:40 AM

Thanks again guys.

 

One more... with the Lunt 60, is imaging as simple as replacing the eyepiece with an appropriately sized CMOS and adjusting the focuser until focus is reached? Or do I need to get "creative"?

It is straight forward.  When you are viewing with an eyepiece you need to slide the blocking filter diagonal out about 1 1/2" so you can focus (many of us didn't realize this when we got our scopes and wondered why we couldn't see anything!), then when you attach the camera you will need to slide the diagonal back in a bit (mine is about 1/2" out with camera) to reach focus with the camera.



#37 Bokchoy Ninja

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Posted 01 June 2020 - 07:07 PM

It is straight forward.  When you are viewing with an eyepiece you need to slide the blocking filter diagonal out about 1 1/2" so you can focus (many of us didn't realize this when we got our scopes and wondered why we couldn't see anything!), then when you attach the camera you will need to slide the diagonal back in a bit (mine is about 1/2" out with camera) to reach focus with the camera.

Awesome, thanks for the reply. Is an ASI120 Mini large enough to capture the full disk, or is an ASI178 needed?

 

Also, is a tilt-adapter required?


Edited by Bokchoy Ninja, 01 June 2020 - 07:07 PM.


#38 rigel123

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Posted 01 June 2020 - 07:43 PM

I believe the full disk would just fit onto the chip on the 178.  It’s probably a good idea to just go ahead and get a tilt adapter, I only have noticeable rings with a Barlow and sometimes they don’t show up even then.  But you can also try flats which will help manage Newton Rings as well.




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