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What does everyone think about the new Lunt 40mm h-alpha telescope coming out? Its smaller a lense but small bandpass too.

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21 replies to this topic

#1 iseegeorgesstar

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Posted 30 July 2020 - 09:59 AM

LUNT 40MM DEDICATED HYDROGEN-ALPHA SOLAR TELESCOPE

Here's the link
https://luntsolarsys...olar-telescope/

It's smaller than their entry level 50mm but the bandpass for the 40mm is .65 while the 50mm is .75

I'm new to telescopes in general. A smaller lens means it captures less light right? But a smaller bandpass means you can see more surface detail?

Do you think features of the sun will be viewable on the 40mm? Can you compensate for this with a barlow and high-end and/or high-magnification eye piece?

I noticed there exists a 35mm lunt halpha scope but they don't seem to sell it anymore. Also the product page for the 40mm has the same pictures of the sun as the 50mm. And they're currently not selling a hardcase for the 40mm which makes me wonder if it's being rushed or if they're just playing it safe until they sell more of these.

Thanks for your thoughts and opinions.

Edited by iseegeorgesstar, 30 July 2020 - 10:00 AM.


#2 SpaceConqueror3

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Posted 30 July 2020 - 10:13 AM

I have no experience with LUNT telescopes but I've had a 40mm Coronado PST for nearly 10 yrs and the aperture is fine as the sun is of course a huge target. In the PST's case at f/10 (same as the LUNT referenced), you can easily apply high power and more than adequately see the small prominences and surface details. So don't worry about it's diminutive aperture.


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#3 iseegeorgesstar

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Posted 30 July 2020 - 12:37 PM

I have no experience with LUNT telescopes but I've had a 40mm Coronado PST for nearly 10 yrs and the aperture is fine as the sun is of course a huge target. In the PST's case at f/10 (same as the LUNT referenced), you can easily apply high power and more than adequately see the small prominences and surface details. So don't worry about it's diminutive aperture.

Interesting. Thank you so much for the reply.

Edit: Also do you (or anyone else) have any ideas/experiences at what size lens the sun begins to look like a sphere and not flat? I saw an amazon review that said they started seeing a sphere when they upgraded, I think, into the 80-100mm++ lens. I've never looked through a h-alpha scope so I have no idea what to expect.

Edited by iseegeorgesstar, 30 July 2020 - 12:47 PM.


#4 bigdob24

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Posted 30 July 2020 - 02:09 PM

Lunt makes a good quality product and what’s even better is there customer service.

I think there just making entry level Ha scopes at a reasonable price to those that don’t want to spend a chunk more aperture.


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#5 Tapio

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Posted 30 July 2020 - 02:26 PM

https://www.cloudyni...scope-from-lunt

#6 iseegeorgesstar

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Posted 31 July 2020 - 09:16 AM

 

Thank you! Going by that post and that comment hear looks like the 40mm is enough for visual purposes but might be limited with imaging needs. Also apparently there's a double stack forthcoming. 



#7 iseegeorgesstar

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Posted 31 July 2020 - 09:17 AM

Lunt makes a good quality product and what’s even better is there customer service.

I think there just making entry level Ha scopes at a reasonable price to those that don’t want to spend a chunk more aperture.

 

They seem like a high-quality company by all regards (according to the internet).

 

Looks like I might be getting my first solar scope soon-ish!



#8 chemman

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Posted 31 July 2020 - 09:56 AM

I have a Lunt modular scope and cannot say enough good about their product and their company and people.  I purchased the scope during COVID and they were absolutely the best people to work with, especially Faye, but everyone was great.  The scope was assembled and tested by them before it shipped. When I recieved it, it worked perfectly.  When a issue came up, I called up and Faye went and asked a tech while I was on the phone looking through my scope.  Turns out I had a spacer used for single stack on the scope causing an issue with the double stack.  Solved in 10 minutes.  

 

Nothing against any other manufacturer but Lunt is a different breed for sure.  

 

I cannot imagine anything from Lunt to be less than excellent.



#9 sunnyday

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Posted 31 July 2020 - 10:00 AM

I have no experience with LUNT telescopes but I've had a 40mm Coronado PST for nearly 10 yrs and the aperture is fine as the sun is of course a huge target. In the PST's case at f/10 (same as the LUNT referenced), you can easily apply high power and more than adequately see the small prominences and surface details. So don't worry about it's diminutive aperture.

technically speaking, you have experience with lunts, since the same guy did pst and lunt now.


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#10 Andre444

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Posted 17 August 2020 - 07:58 AM

Hi,  solar folks . the scope looks very nice, maybe I will sell my pst and will do a new expirience with the new lunt 40 with its helical focuser, Bigger BF  .... if this scope can show you More details and can yield more magnification/ brighter views than at last some made PST models, I dond  Know. If so, I wold be a nice upgrade! Thanks. 


Edited by Andre444, 17 August 2020 - 08:24 AM.


#11 SloMoe

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Posted 17 August 2020 - 08:40 AM

So, so far no one's actually used one?



#12 BYoesle

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Posted 17 August 2020 - 11:25 AM

 

I'm new to telescopes in general. A smaller lens means it captures less light right? But a smaller bandpass means you can see more surface detail?

 

It's a little more complex. Telescope aperture is resolution and light gathering. So larger is linearly proportional to resolution and light gathering area of the objective is logarithmically increased for greater brightness. Therefore doubling the aperture doubles the resolution ("detail"), and increases brightness proportionally to the increase in the radius squared (as in A = pi r^2).

 

Bandpass is more closely related to contrast, and the difference between a single stacked 0.75A and 0.65A filters generally would be subtle. The best way to improve contrast is to "double stack" two filters in series. When you do this the bandpass is marginally narrowed, but the shape of the filter transmission is greatly improved to suppress photospheric continuum at +/- 0.65 A and beyond on either side of the center wavelength. The level of "detail" (resolution) is unchanged, but the contrast of disc features is improved by the removal of parasitic continuum from the photosphere (aka low level signal - "noise'). However, peak transmission is reduced, so the overall image is less bright (in addition to removal of parasitic continuum):

 

double stacking normalized.jpg

Double stacking. Note no change in "detail" (resolution); great change in contrast. Click for larger.

 

This is why more aperture is also desirable when double stacking etalons.


Edited by BYoesle, 17 August 2020 - 11:42 AM.

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#13 bandazar

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Posted 17 August 2020 - 03:22 PM

Yep, I guess BYoesle comments are relatively correct.  However, if you go all the way down to 0 angstroms, then no light is getting through, so you would see nothing.  And imo, double stacking in small apertures is probably not worth it.  And double stacking does have some negatives to it that you have to consider as well too - reflections, complexity in collimation, more glass can mean a less sharper image if there is more dust, expense and weight, can dim the image so that some objects (such as flares) are lost, and improvement is so marginal that it just not justify the cost.  If I were to go low angstrom, I'd just as well get a single stack.  And hopefully it should be paired with an ERF that lets in just the right amount of light.

The advantage of double stack is flexibility in changing angstroms.

I guess angstroms will be akin to pixel density in monitors, while resolution would be akin to display resolution, and aperture would be akin to the size of the monitor, as an analogy. 



#14 briansalomon1

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Posted 17 August 2020 - 09:45 PM

It's a little more complex. Telescope aperture is resolution and light gathering. So larger is linearly proportional to resolution and light gathering area of the objective is logarithmically increased for greater brightness. Therefore doubling the aperture doubles the resolution ("detail"), and increases brightness proportionally to the increase in the radius squared (as in A = pi r^2).

 

Bandpass is more closely related to contrast, and the difference between a single stacked 0.75A and 0.65A filters generally would be subtle. The best way to improve contrast is to "double stack" two filters in series. When you do this the bandpass is marginally narrowed, but the shape of the filter transmission is greatly improved to suppress photospheric continuum at +/- 0.65 A and beyond on either side of the center wavelength. The level of "detail" (resolution) is unchanged, but the contrast of disc features is improved by the removal of parasitic continuum from the photosphere (aka low level signal - "noise'). However, peak transmission is reduced, so the overall image is less bright (in addition to removal of parasitic continuum):

 

attachicon.gifdouble stacking normalized.jpg

Double stacking. Note no change in "detail" (resolution); great change in contrast. Click for larger.

 

This is why more aperture is also desirable when double stacking etalons.

Excellent tutorial as usual Bob. You remind me so much of the Phds I worked with at Litton/Northrop I've wanted to ask if you do have a degree.



#15 BYoesle

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Posted 17 August 2020 - 11:56 PM

Thanks Brian,

 

I have an AS in Natural Sciences and BS in Business Management and Communication.

 

I've been a field paramedic for 40 years...

 

Corovid prep Bob 1 SM.jpg

 

But science and astronomy have been my path to the truth since I was a child:

 

Collection sm2.jpg

 

Top left is my first homemade telescope: a 6 inch f/8 cardboard tube Newt on a pipe mount. I ground and figured the mirror in the 7th grade (seen next to my first telescope - received as a 1962 Christmas present - a 60 mm Unitron ;-). Following this almost exactly 50 years (!) ago was the 8 inch f/7 with a resin covered cardboard tube I built in the 8th grade - also made the mirror, but had to go with an equatorial. Got serious with the 12.5 inch Cave in 1975, most spectacular views of the moon and planets ever! Added the Daystar filter in 1976 on the piggybacked 80 mm f/15 refractor... The start of my long detour into all things solar and culminating (thus far anyway) with the SM140/90 DS DIY project. I'm headed back to the dark side a bit now - last picture is my toilet roll OTA model of my iminent retirement project - a 20 inch f/5 Zambuto primaried Newt on a split-ring equatorial... piggybacking my AP130 EDT - hopefully done sometime next year.


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#16 rigel123

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Posted 18 August 2020 - 05:34 AM

Wow, that Cave is a beast! I ground and polished an 8” all through high school and finally finished it after I graduated college!
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#17 Andre444

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Posted 18 August 2020 - 06:58 AM

Hi, I think maybe  Is not that problem if the image is somewhat dimmer in doublestack ( you can put black cloth over your head and dond know how bright the Lunt 40 will be?)  which I might find more problematic  is to tune the image and the smaller  sweetspot to bring all the details together. Also, some say that in single stack the image looks more natural- the filaments looks ofthen too dark in double stack- other say that it might Be better for imaging while visually  You will see a nice " 3D " effect with dark and lighter eria's and clearer details. 


Edited by Andre444, 18 August 2020 - 11:50 AM.


#18 Eddgie

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Posted 18 August 2020 - 12:08 PM


Edit: Also do you (or anyone else) have any ideas/experiences at what size lens the sun begins to look like a sphere and not flat? 

The sun will never look like a sphere in any size telescope.  It is to far away, and to see a sphere, you would need parallax but even with a big binocular, the sun is too far away to appear as a sphere. Now there may be cases where the brain is tricked into perceiving it as spherical but that is just an illusion that only some might see, and probably then, only sometimes.

 

It is still pretty magnificent though. 



#19 briansalomon1

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Posted 18 August 2020 - 12:13 PM

Cool scopes Bob.

 

I have some formal training in optics and about 8 years working directly with some of the best Physicists at Litton/Northrop but I can clearly see your grasp of at the very least H-aplha optics goes far beyond mine and your degrees don't appear to match your understanding of optics.

 

I know you did it, but I'm curious how you've gained so much knowledge of optics.


Edited by briansalomon1, 18 August 2020 - 12:14 PM.


#20 briansalomon1

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Posted 18 August 2020 - 12:27 PM

Hi, I think maybe  Is not that problem if the image is somewhat dimmer in doublestack ( you can put black cloth over your head and dond know how bright the Lunt 40 will be?)  which I might find more problematic  is to tune the image and the smaller  sweetspot to bring all the details together. Also, some say that in single stack the image looks more natural- the filaments looks ofthen too dark in double stack- other say that it might Be better for imaging while visually  You will see a nice " 3D " effect with dark and lighter eria's and clearer details. 

So many of the old timers here said binoviewing was the best way to improve H-alpha viewing that I decided to spring for one. I bought a used Baader MK IV that without question produced a 3-D effect, at least looking at a stand of trees at ~50X but it didn't make the Sun appear spherical to me. I do think BV is the way to go before adding a 2nd etalon.


Edited by briansalomon1, 18 August 2020 - 12:28 PM.


#21 BYoesle

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Posted 18 August 2020 - 01:13 PM

... your degrees don't appear to match your understanding of optics.

 

 

Hi Brian,

 

You're giving me way too much credit. Just began early as an ATM, plus a native curiosity and drive to discover the how and why of the way things work...



#22 briansalomon1

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Posted 18 August 2020 - 02:24 PM

I know enough to recognize the technical strengths of the people around me. One member of the Technical Staff at Litton/Northrop had no degree either. He was equal with our top Engineer, Radha Mandyam who was Designer of Mirrors there. I just wanted to know how you came up.




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