Lunt CaK max aperture?

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Lunt CaK max aperture?

Post by TareqPhoto »

Hi,

What is the maximum aperture size allowed or compatible with Lunt CaK Module/filter???


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Re: Lunt CaK max aperture?

Post by JochenM »

By Lunt specifications: 100mm (which is a ton of aperture for CaK imaging).


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Re: Lunt CaK max aperture?

Post by TareqPhoto »

JochenM wrote: Sun May 15, 2022 6:07 am By Lunt specifications: 100mm (which is a ton of aperture for CaK imaging).
I see, ok, thank you very much


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Re: Lunt CaK max aperture?

Post by TareqPhoto »

OK, i saw images someone did use his 130mm scope for both Ha with the Quark and CaK with Lunt module, i think i will go with 120 or Bresser 127L after all, i was thinking about 152L, but i don't want to risk with wrong choice, i want to have close ups, so if that 127L/1200 is more than enough then i will ignore 152L.


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Re: Lunt CaK max aperture?

Post by christian viladrich »

Hello,

Years ago I used a Lunt Ca K on my 150 mm f/7 refractor. This beeing said, running beyond Lunt specifications is at your own risk ;-)

A friend used one on a 200 mm refractor. The filter was damaged.


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Re: Lunt CaK max aperture?

Post by marktownley »

TareqPhoto wrote: Mon May 16, 2022 1:21 am OK, i saw images someone did use his 130mm scope for both Ha with the Quark and CaK with Lunt module, i think i will go with 120 or Bresser 127L after all, i was thinking about 152L, but i don't want to risk with wrong choice, i want to have close ups, so if that 127L/1200 is more than enough then i will ignore 152L.
I use my CaK filter (not lunt) on my Bresser 127L stopped down to 120mm and use a 2" astronomik uv/ir filter sub aperture ERF no problems.


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Re: Lunt CaK max aperture?

Post by TareqPhoto »

marktownley wrote: Mon May 16, 2022 7:20 pm
TareqPhoto wrote: Mon May 16, 2022 1:21 am OK, i saw images someone did use his 130mm scope for both Ha with the Quark and CaK with Lunt module, i think i will go with 120 or Bresser 127L after all, i was thinking about 152L, but i don't want to risk with wrong choice, i want to have close ups, so if that 127L/1200 is more than enough then i will ignore 152L.
I use my CaK filter (not lunt) on my Bresser 127L stopped down to 120mm and use a 2" astronomik uv/ir filter sub aperture ERF no problems.
Which CaK filter? And can i see results please??!!


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Re: Lunt CaK max aperture?

Post by mike_fos »

One Question: I want to use Lunt CaK B1200 with 120 ED Skywatcher f=900 stopped to 90 mm. What about to use a barlow for detail views?


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Re: Lunt CaK max aperture?

Post by marktownley »

mike_fos wrote: Tue May 17, 2022 3:56 pm One Question: I want to use Lunt CaK B1200 with 120 ED Skywatcher f=900 stopped to 90 mm. What about to use a barlow for detail views?
What camera are you using?


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Re: Lunt CaK max aperture?

Post by marktownley »

TareqPhoto wrote: Mon May 16, 2022 10:37 pm
marktownley wrote: Mon May 16, 2022 7:20 pm
TareqPhoto wrote: Mon May 16, 2022 1:21 am OK, i saw images someone did use his 130mm scope for both Ha with the Quark and CaK with Lunt module, i think i will go with 120 or Bresser 127L after all, i was thinking about 152L, but i don't want to risk with wrong choice, i want to have close ups, so if that 127L/1200 is more than enough then i will ignore 152L.
I use my CaK filter (not lunt) on my Bresser 127L stopped down to 120mm and use a 2" astronomik uv/ir filter sub aperture ERF no problems.
Which CaK filter? And can i see results please??!!
Something like this https://brierleyhillsolar.blogspot.com/ ... -june.html

There's quite a few from 2021 with the 127


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Re: Lunt CaK max aperture?

Post by TareqPhoto »

marktownley wrote: Tue May 17, 2022 7:53 pm
TareqPhoto wrote: Mon May 16, 2022 10:37 pm
marktownley wrote: Mon May 16, 2022 7:20 pm

I use my CaK filter (not lunt) on my Bresser 127L stopped down to 120mm and use a 2" astronomik uv/ir filter sub aperture ERF no problems.
Which CaK filter? And can i see results please??!!
Something like this https://brierleyhillsolar.blogspot.com/ ... -june.html

There's quite a few from 2021 with the 127
Ok, this is great enough for both CaK and Ha, i don't think i will regret getting this 127L or miss to go larger to 150 aperture, after all if i want to go larger than 120 for Ha at least then i have Newt or Mak, i can use kind of frontal ERF, while for CaK from Lunt i must stay with 120 aperture as they mentioned.


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Re: Lunt CaK max aperture?

Post by Valery »

christian viladrich wrote: Mon May 16, 2022 5:11 pm Hello,

Years ago I used a Lunt Ca K on my 150 mm f/7 refractor. This beeing said, running beyond Lunt specifications is at your own risk ;-)

A friend used one on a 200 mm refractor. The filter was damaged.
One of my clients (has bought the ARIES 7" Fluorite apo) has destroyed his Lunt CaK B1800 module in the same way. :(


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Re: Lunt CaK max aperture?

Post by marktownley »

I guess the energy load will increase with the square of the increase in aperture...


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Re: Lunt CaK max aperture?

Post by MalVeauX »

Tareq,

Do not stress big aperture with near UV wavelengths. 393nm is nearly 59~60% higher angular resolution than 656nm H-alpha, and accordingly needs significantly better seeing conditions. A 100mm aperture critically sampled in 393nm Calcium is equivalent to about a 150mm aperture critically sampled in 656nm H-alpha. Trying to use a 150mm aperture critically sampled in calcium will be like using an 8~9 inch aperture for h-alpha. Your seeing would need to be far better than 0.8 arc-seconds to even begin to be an option other than a smear. Short wavelengths are also much more effected by seeing than long wavelengths are. So 1 arc-second in Calcium is not the same as 1 arc-second in H-alpha.

You'll be fine with 100m more or less with Calcium until you get a lot more experience and knowledge with this. Then if it's something you want to push the limits of, by all means, go for it.

Lunt's module states 100mm aperture max for energy rejection needs on its own. This is to cover the heat loading cycle on the filters to avoid them being rapidly destroyed in a short period of time. You can certainly use it with larger, but the increase thermal load will wreck the filters faster. See above comments. Energy goes up very fast with larger apertures. You can absolutely use it with larger apertures with a primary energy rejection filter prior to the Lunt module, like a 2" blue ccd imaging filter (make sure it passes 393nm with high transmission, many pass it with low transmission). One of the better transmissions right now for least cost is the ZWO blue 2" imaging filter. Or, if you want to spend, Baader's k-line 2" filter is good as an energy rejection filter for this purpose. But I wouldn't use it over 127mm aperture anyways and would stress full aperture on 150mm or larger without a different cooling system. But again, bottom line, you will rarely make capital use of greater than 100mm aperture in calcium due to the limits of seeing and the significance of its angular resolution and how easily its perturbed by seeing.

Don't stress it. Get some moderate resolution solar imaging under your belt before you worry about this. Any system you build to image solar with a refractor will work fine with calcium as long as it has a 2 inch focuser and you can mask the aperture to increase the focal-ratio. Get some images in H-alpha or photosphere/continuum and some experience with this, before stressing calcium aperture maximums.

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

Here's 102mm (4") aperture high resolution calcium k at 0.31"/pixel image scale from the past few weeks so this is recent, this required 0.7~0.8 arc-second seeing, and this is still not the max of this potential aperture's resolution, as it was seeing limited.

Image

Image

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

Here's 120mm aperture high res calcium at the same 0.31"/pixel iamge scale from a few weeks ago in better than 0.7 arc-second seeing conditions. And again, this is still not the max of this potential aperture in this wavelength. It's seeing limited. And going bigger needs even better seeing. It's not practical unless its your true passion and you have the time and seeing to do it.

Image

Very best,


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Re: Lunt CaK max aperture?

Post by RomanH »

I totally agree especially with this last post. I have 155mm f8 APO and for CaK I would use something smaller - e.g. 100mm aperture is totally ok. You'll get a lots of resolution and you will do not need excellent seeing condition. Also the heat would not be so excessive as with 150mm aperture.

This is the best result so far with 155mm aperture and Daystar Quark CaH (5A, 396nm):
Image


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Re: Lunt CaK max aperture?

Post by TareqPhoto »

Well, it is either 100 aperture or 120 or 150, and i already mentioned i don't want to jump with different refractors even later, so i buy once and only, and i feel like why buy 100, i have 90mm triplet and 80mm achromatic which both can be handy close to 100, so buying 100/102 for me will be like a waste as i am sure i want to upgrade later to something like 115 or 120 or 130 in this range, and now with your comments i think i better go with 120 or that Bresser 127L and never look back.

It is not about gaining experience for me, it is about what to buy once, to gain experience i can use 90 and 72 and 80 and 60 refr all i have, or my Newt 6"/8" or 7" Mak, and i did see someone used 150 for CaK, i just don't need to follow others risks, i know some can damage their gear and buy another, i will never do that, i don't have this premium opportunity to risk, but i also can't spend twice, i also don't have CaK module anyway to start with, but i do have Quark Ha and white light which both can be fine with larger aperture at some points.


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Re: Lunt CaK max aperture?

Post by TareqPhoto »

MalVeauX wrote: Sat May 21, 2022 2:28 pm Tareq,

Do not stress big aperture with near UV wavelengths. 393nm is nearly 59~60% higher angular resolution than 656nm H-alpha, and accordingly needs significantly better seeing conditions. A 100mm aperture critically sampled in 393nm Calcium is equivalent to about a 150mm aperture critically sampled in 656nm H-alpha. Trying to use a 150mm aperture critically sampled in calcium will be like using an 8~9 inch aperture for h-alpha. Your seeing would need to be far better than 0.8 arc-seconds to even begin to be an option other than a smear. Short wavelengths are also much more effected by seeing than long wavelengths are. So 1 arc-second in Calcium is not the same as 1 arc-second in H-alpha.

You'll be fine with 100m more or less with Calcium until you get a lot more experience and knowledge with this. Then if it's something you want to push the limits of, by all means, go for it.

Lunt's module states 100mm aperture max for energy rejection needs on its own. This is to cover the heat loading cycle on the filters to avoid them being rapidly destroyed in a short period of time. You can certainly use it with larger, but the increase thermal load will wreck the filters faster. See above comments. Energy goes up very fast with larger apertures. You can absolutely use it with larger apertures with a primary energy rejection filter prior to the Lunt module, like a 2" blue ccd imaging filter (make sure it passes 393nm with high transmission, many pass it with low transmission). One of the better transmissions right now for least cost is the ZWO blue 2" imaging filter. Or, if you want to spend, Baader's k-line 2" filter is good as an energy rejection filter for this purpose. But I wouldn't use it over 127mm aperture anyways and would stress full aperture on 150mm or larger without a different cooling system. But again, bottom line, you will rarely make capital use of greater than 100mm aperture in calcium due to the limits of seeing and the significance of its angular resolution and how easily its perturbed by seeing.

Don't stress it. Get some moderate resolution solar imaging under your belt before you worry about this. Any system you build to image solar with a refractor will work fine with calcium as long as it has a 2 inch focuser and you can mask the aperture to increase the focal-ratio. Get some images in H-alpha or photosphere/continuum and some experience with this, before stressing calcium aperture maximums.

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

Here's 102mm (4") aperture high resolution calcium k at 0.31"/pixel image scale from the past few weeks so this is recent, this required 0.7~0.8 arc-second seeing, and this is still not the max of this potential aperture's resolution, as it was seeing limited.

Image

Image

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

Here's 120mm aperture high res calcium at the same 0.31"/pixel iamge scale from a few weeks ago in better than 0.7 arc-second seeing conditions. And again, this is still not the max of this potential aperture in this wavelength. It's seeing limited. And going bigger needs even better seeing. It's not practical unless its your true passion and you have the time and seeing to do it.

Image

Very best,
Thank you very much!

Hey Marty, this is 120mm scope, too much :D ;)

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Re: Lunt CaK max aperture?

Post by marktownley »

RomanH wrote: Sat May 21, 2022 7:26 pm I totally agree especially with this last post. I have 155mm f8 APO and for CaK I would use something smaller - e.g. 100mm aperture is totally ok. You'll get a lots of resolution and you will do not need excellent seeing condition. Also the heat would not be so excessive as with 150mm aperture.

This is the best result so far with 155mm aperture and Daystar Quark CaH (5A, 396nm):
Image
This is an excellent image Roman, especially viewed full size!


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Re: Lunt CaK max aperture?

Post by marktownley »

TareqPhoto wrote: Sat May 21, 2022 9:37 pm that Bresser 127L and never look back.
This is the one I have and would recommend you go with Tareq. It offers great bang for the buck, and can always be stopped down when conditions don't allow.


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Re: Lunt CaK max aperture?

Post by RomanH »

Thank you. I have more images with original resolution on https://astrofotky.cz/~rick. I was also very happy and suprised with the results, since it was captured only from the balcony in the city. I revived one old thread I started long time ago, to update my status with solar imaging with the latest hi-res images and some composite here: viewtopic.php?t=22758, (the post is waiting for the approval).


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Re: Lunt CaK max aperture?

Post by TareqPhoto »

marktownley wrote: Sun May 22, 2022 7:15 am
TareqPhoto wrote: Sat May 21, 2022 9:37 pm that Bresser 127L and never look back.
This is the one I have and would recommend you go with Tareq. It offers great bang for the buck, and can always be stopped down when conditions don't allow.
Great, i just have to wait longer a bit, first because i need the budget to save for it, and second because it is the summer here and the sun is getting hotter in our skies.

Thank you


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