Ca K telescope

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Ca K telescope

Post by TheHubby »

Since I favour Calcium K, I would like to upgrade from the CaK PST (since I can never get on it).

Alexandra suggests this Exp Scientific 102mm http://www.telescopehouse.com/acatalog/ ... ntial.html with a CaK module from here http://luntsolarsystems.com/blog/cak-modules

would they work OK together?

The hubby


Negative comments welcome to aid learning, as competing with Alexandra on her old borrowed equipment means I will always be 3 steps behind.
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Re: Ca K telescope

Post by marktownley »

Hey there! :)

A nice scope, however I would save yourself a whole load of money and get better results by getting a simple fraunhofer refractor for CaK - they work better than ED scopes or triplets. Counter intuitive I know, but the simpler glass and optical coatings are much better at the shorter wavelengths.

You could consider a Tal100R http://astronomia.co.uk/index.php/teles ... scope.html or a Celestron Omni XLT 102 http://www.firstlightoptics.com/omni-xlt-series.html You saw my 100mm Tal at the International Astronomy Show. These are the only two 100mm scopes I would get for CaK work.

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Re: Ca K telescope

Post by swisswalter »

Hi Hubby


I second Mark's opinion. A simple achro is good in combination with a LUNT B1200 and the secret filter of the PST added will top every thing ;-) :hamster: :hamster: :hamster: :hamster:


PS. That combo also works on a WO 110 ;-)


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Re: Ca K telescope

Post by marktownley »

One more thing to add, if you do want to spend big bucks on a scope then a frac with a fluorite lens is better still than a fraunhofer...


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Re: Ca K telescope

Post by swisswalter »

Hi Hubby

I second what Mark wrote. My TAK 102 works very well with my Klunt filter combo and would work even better with the CaK PST filter added to the combo ;-)


Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

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Re: Ca K telescope

Post by Montana »

Hey chaps, you are starting to speak another language :? I was hoping to get him something similar to a CaK PST but a 60-80mm version, however I have found that Lunt don't do an all in one CaK scope. So I was hoping there would be something small, simple and compact for easy set up etc. Finding a CaK PST seems to be impossible, something like a TAK is also impossible Walter.

Does Joe Sullivan use the Celestron 102? I am not sure if the C102 is a code for this what Mark suggested?

Thanks for your help guys :)

Alexandra


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Re: Ca K telescope

Post by solarchat »

Montana-man

Lunt certainly does do an all in one CaK scope. They have a line of white light doublets that are very reasonably priced and they will sell you a Lunt B1200 and a 60/80 or 100mm refractor with it if you want.

I personally use the exact thing Montana-woman recommends for outreach and all my imaging, the Exp Sci 102mm APO and B1200 CaK .

feel free to email rikki at Lunt to get whatever you want headed your way. I would suggest that if you are going ahead and buying a refractor / CaK setup that you add a Lunt white light wedge to the deal all together. They are less than $300 and will allow you to quickly switch out diagonals for white light or CaK.


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Re: Ca K telescope

Post by marktownley »

Hey chaps, you are starting to speak another language :? I was hoping to get him something similar to a CaK PST but a 60-80mm version, however I have found that Lunt don't do an all in one CaK scope. So I was hoping there would be something small, simple and compact for easy set up etc. Finding a CaK PST seems to be impossible, something like a TAK is also impossible Walter.

Does Joe Sullivan use the Celestron 102? I am not sure if the C102 is a code for this what Mark suggested?

Thanks for your help guys :)

Alexandra

Yes, Joe Sullivan use a C102.

You can get the CaK scope over here http://www.iankingimaging.com/show_product.php?id=1095

Personally if that is the route you want to go I would get just the diagonal and then maybe a 60-70mm frac to go with it - will work out alot cheaper and you could use it as a spotting scope for birding.


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Re: Ca K telescope

Post by hunterknox »

I went through quite a few 4" refractors when I was in my PST modding phase. The Tal's a very good achromat - a little rustic in terms of the mechanical build and finish but it terms of the optical quality it's definitely a cut above the Celestrons and Skywatchers in a similar price bracket (or at least the examples I tried).

It's also worth considering the Lyra Optic f11, which is mechanically superior and has a pretty decent dual speed focuser.

If you can deal with the long focal length and resulting image scale I'd go for one of those two. If not then, like Mark says, something smaller may be a better idea.


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Re: Ca K telescope

Post by Montana »

Thanks for the info, we were having a good chat about it over breakfast. I thought Stephen had the Explore Scientific.

Mark, they are very expensive for a 60mm, it would be better to get 100mm for the same price. I asked what he enjoyed doing and it seems looking at the spots up close so I think 80-100mm would be better. It is very interesting the Celestron works very well as we would be able to get this from Rick at Stockport Telescope shop, I prefer to keep him in business. We need to do some measuring up to see if it will fit in the dining room, as hubby needs it to be permanently set up and ready to go (he doesn't like fiddling about). But the Celestron looks very long and he doesn't seem too keen.

Next problem is the Lunt module, I am not sure that Rikki will deal with me as I am from Europe, last time I tried a few years back they pushed me to deal with Lunt Europe and they are 3x the price of the US (not including our tax). I will have to see how much Ian King would sell us one for and try and compare the price, we have no problem importing from the US (if allowed) as we have done this before with the TEC. It will need a few inquiries.
Does Rikki have a direct e-mail? just to increase the chances of not being ignored and forwarded to Lunt Europe?

Many thanks
Alexandra and hubby


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Re: Ca K telescope

Post by marktownley »

Ahhh, regards the scopes then, if SBTC is going to be getting some business I would recommend in my order of preference:

1) http://www.telescopesandbinoculars.co.u ... -1474.html - Walter has one of these, i'm sure he'll tell you his thoughts on it.

2) http://www.telescopesandbinoculars.co.u ... -1256.html

3) http://www.telescopesandbinoculars.co.u ... -1255.html

For a bit more aperture they sell my original recommendation http://www.telescopesandbinoculars.co.u ... -1723.html

Regards the Lunt wedge I would just order direct from Teleskop Service in Germany, they have them in stock currently http://www.teleskop-express.de/shop/pro ... cuser.html I've bought from these (high value items) a number of times and can only whole heartedly recommend them, there are also no associated customs charges to pay either...

HTH!

Mark :)


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Re: Ca K telescope

Post by solarchat »

Hocking Rikki


its not that the prices are 3x higher for nefarious reasons, its just the massive amount of government tariffs imposed on imported items. I have the same problem with the $40k worth of solar gear going to Australia. Having to pay almost the full retail here in the states on top of buying it to get it into Oz.


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Re: Ca K telescope

Post by Montana »

Thanks guys :thanx:

We need to do some research and measuring now :)

Alexandra


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Re: Ca K telescope

Post by marktownley »

No worries, keep us updated as to proceedings :)


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Re: Ca K telescope

Post by robert »

I use an Skywatcher ED80 with a Lunt600 CaK module and it is really good. The module fits an ED100 as well and is great.
Robert


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Re: Ca K telescope

Post by sullij1 »

Hi, Sorry I missed this thread. Send Hubby my regards.

Yes, I use the Celestron 102, and yes, it is very long. It is not a grab and go sitting in a corner of the family room. The tube sits in the corner in a nice bag next to the mount. It all has to be hauled out and set up. Takes about 15 minutes to get up and running.

I Like Stephens suggestion for a grab and go.

Gotta say that the Celestron 102 isn't that much of a hassle to set up. (the images coming from it ROCK!)

My Celestron 11 inch and CGE are a hassle to set up. My back tells me so. :lol:

I also recommend the Rigel NFocus, focus motor. Makes focusing from under a hood Soooooo easy.

Stay with the B1200 and B1800 size Lunt modules. Brightness matters, so does the FOV when trying to keep the full disk in the Field Of View.

I hope you find an affordable easy solution in the UK.

Cheers


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Re: Ca K telescope

Post by sullij1 »

One more thing - When Astrodan let me use his Explore 102 to shoot with, I must say that it was easier to handle than the C102 and although the Explore produces a slightly softer image(probably due to shorter focal length), it was a very nice kit. The image softness can be fixed in post processing.


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Re: Ca K telescope

Post by sullij1 »

Hubby,

OK, now ya got me going. Seeing how ya are gonna lay out a pretty penny for this I will give ya some observations. First, these are my opinion and I am not in any way trying to denigrate any colleagues’ work or implying I am the expert. Just observations.

I say go with the K-line B1200 or B1800 or B3400 because as I look at the imagery coming from the smaller B600 and smaller diameter and shorter focal length/ratio scopes, it seems the smaller the optical components, the more one loses the umbra and penumbra details in the image.

I changed my order from a B1200 to a B1800 and am soooo happy I did. Financially it hurt!!!!! But the imagery I am getting speaks for itself. I am not sorry I went for the larger filter, especially when I go after the 5X images. In my opinion the longer focal length, larger filter and aperture are making all the difference.

I will be happy to post via you tube, raw imagery etc. to demonstrate my point or show ya what the image looks like at higher magnification if that is what you are looking for. Really just want you to be happy with your purchase.

Best,

Joe

( please excuse crummy spelling and red neck dialect.)


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Re: Ca K telescope

Post by Derek Klepp »

I picked up a cheap ED 102 which is easy to set up and haul around.I am happy with my B1200 but Joe has a point on the variances between them.Basically my B1200 sits on an 80mm f6 APO for quick discs. As you guys travel I think a good 100mm that could go with you or even a 90 may be the go.One has to also look at the versatility of the scope you are purchasing or you end up with a lot of glass that doesn't get used enough.I would also get Pedros view on this as he has tested a lot of scopes with CaK.Just my two bobs worth.Also and I'm out on a limb here do you need to consider a unit that on occasion will be put on the TEC 140.
Cheers Derek


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Re: Ca K telescope

Post by astrodanco »

To echo what Joe said, imaging outside in the bright sunshine doesn't work for me. I remote everything into the house. I have cables for the mount, focus motor and camera all running indoors. I've been using the Rigel Systems nFocus DC focus motor and hand controller. Some people might prefer the stepper motor version.


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Re: Ca K telescope

Post by Montana »

Thanks guys for the wealth of information :)

We had a long discussion last night and nearly settled on the Celestron 102 but then couldn't find a simple mount for it. They all come with an equatorial and he wasn't too keen on that. All the alt/az require short tubes. So we went round in a bit of a circle :( back to the drawing board of thought again.

Alexandra


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Re: Ca K telescope

Post by astrodanco »

You can purchase a C102 OTA from OPT for US$99.95 (see here) without any mount and then place it on whatever mount you like. The stock C102 OTA has a short Vixen dovetail that works with any mount with a dovetail saddle that can accept a Vixen dovetail. Or you can purchase a #102CLSCCRDL cradle ring from Explore Scientific for US$51.99. Just place a few rubber washers on the knobs to make them clamp tight onto the C102 OTA.

C102 OTA from OPT:



Cradle Ring from Explore Scientific:



Oops, just noticed that's an OPEN BOX item there at OPT.


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Re: Ca K telescope

Post by Montana »

Thanks for that info :) it's not just the buying it separately bit, we can't find a mount other than the equatorial one which will take a 1 meter tube ;)

Alexandra


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Re: Ca K telescope

Post by swisswalter »

Hi Alexandra

don't worry. I have a Losmandy GM8 left for sale, only 800 €. But it will cary 3 of your scopes ;-)


Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

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Re: Ca K telescope

Post by marktownley »

Thanks guys for the wealth of information :)

We had a long discussion last night and nearly settled on the Celestron 102 but then couldn't find a simple mount for it. They all come with an equatorial and he wasn't too keen on that. All the alt/az require short tubes. So we went round in a bit of a circle :( back to the drawing board of thought again.

Alexandra

Ahh, you have your alt/az Ioptron(?) mount don't you - take it you want to use that? simples then, a 70mm f6 ed scope - something like http://www.altairastro.com/product.php? ... 270&page=1 spend the money you save on the scope on bigger blocker cak filter...


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Re: Ca K telescope

Post by hunterknox »

I used to use an iOptron Minitower mount with my Tal PST mod. It worked but it wasn't what you'd call confidence inspiring. There is the Pro version available - that has a higher capacity but I wouldn't want to pay what it costs to find out whether it works or not.


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Re: Ca K telescope

Post by sullij1 »

Is anybody doing solid, consistent image runs on Alt/AZ mounts? Equatorial seems to be the standard for imaging. ALT/AZ for grab and go visual - Right?


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Re: Ca K telescope

Post by astrodanco »

Certainly not for imaging. For outreach I tried Alt/Az mode with the AZ-EQ6 mount. It promised much. It didn't deliver. Now I use it in EQ mode only.


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Re: Ca K telescope

Post by Montana »

Is there any particular reason you don't like the alt/az other than field rotation?

We have asked for a quote from Rick for a Celestron Omni 102 and an iOptron Minitower Pro. The iOptron MT Pro gets a good review from Ian Morison and I remember him loving it and showing it off at a 'show and tell' at the astro club, he was using it with a Takahashi 130.

Any opinions welcome, I have asked for Rick's opinion too.

Alexandra and hubby


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Re: Ca K telescope

Post by pauljones »

I don't do solar imaging on an alt/az mount but I do all my planetary and lunar imaging with a ServoCat driven Dobsonian. If you keep the video runs short enough, field rotation is not an issue. It seems to work.

It makes animations annoying as over a long period of time, field rotation is obvious. But for just one image, it's fine. Solar video runs (in my hands, at least) are shorter, so I think would also be fine. If you have a choice and the money, EQ is better. But if you own an alt/az, you can use it.

I assume here it is a driven alt/az of course.


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Re: Ca K telescope

Post by marktownley »

Is there any particular reason you don't like the alt/az other than field rotation?

We have asked for a quote from Rick for a Celestron Omni 102 and an iOptron Minitower Pro. The iOptron MT Pro gets a good review from Ian Morison and I remember him loving it and showing it off at a 'show and tell' at the astro club, he was using it with a Takahashi 130.

Any opinions welcome, I have asked for Rick's opinion too.

Alexandra and hubby

Any reason you're plugging for the alt /az over the eq?


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Re: Ca K telescope

Post by TheHubby »

Any reason you're plugging for the alt /az over the eq?

Evening Mark,

For non physics people like me, I just want a tripod and mount to work when I pick it up and not have to work out where north is, what the weight is like e.t.c.

The little Merlin does this for me and when I see Alexandra spend 15 minutes mastering the EQ6 I think she could be observing rather than fiddling.

You have to remember I have the attention span of a gnat and need to pick equipment up, work with it and put it away quickly. I won't be spending hours outside, only about an hour. The alt az mounts are built for simple astronomers like me, but I realise they are inferior.


Negative comments welcome to aid learning, as competing with Alexandra on her old borrowed equipment means I will always be 3 steps behind.
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Re: Ca K telescope

Post by marktownley »

Any reason you're plugging for the alt /az over the eq?

Evening Mark,

For non physics people like me, I just want a tripod and mount to work when I pick it up and not have to work out where north is, what the weight is like e.t.c.

The little Merlin does this for me and when I see Alexandra spend 15 minutes mastering the EQ6 I think she could be observing rather than fiddling.

You have to remember I have the attention span of a gnat and need to pick equipment up, work with it and put it away quickly. I won't be spending hours outside, only about an hour. The alt az mounts are built for simple astronomers like me, but I realise they are inferior.

Ahhh, fair enough. I'm probably just slap dash with my EQ, all I do is take it out, plonk it to face north and away I go, minute or two max....


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Re: Ca K telescope

Post by swisswalter »

Hi Hubby

here the same, I take out the EQ6, put it on the place it was setup and aligned and shoot. A matter of some minutes. The G11 I even leave in the garden the whole year with a bag on top of it. Setup time 90 seconds ;-)


Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

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Re: Ca K telescope

Post by Valery »

Hello all,

Let me add, solar funs, that a telescope for CaK is not that simple optically. The reason is that at this wave length _all_ refractors have severe spherical aberration, OVERCORRECTION. In other words, their objectives have longer focus for outer zones and shorter focus for central zones. Of course, we consider that these refractors you all use for CaK telescopes are visual refractors and optimized for cental wave lengths (yellow-green for a human eye).
So, a CaK telescope must be specially made and figured/optimized for a 393nm wave length.

Which scopes are the best for CaK from what you ca find on the market?

1. Takahashi's TOA-130. These telescopes have orthochromatic color correction and better corrected (for SA) at 393nm.
2. Simpliest Fraunhoffer refractors of smaller apertures and very long F/D, at least F/10 and also they need to be severely
UNDERcorrected for green light.

All shorter achromats and especially ED doublet and triplets will work with severe SA at the demanded CaK line.


Hope this helps.


Valery.
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Ukraine.


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Re: Ca K telescope

Post by marktownley »

I like your description of SA valery 8)


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Re: Ca K telescope

Post by brianb11213 »

Is there any particular reason you don't like the alt/az other than field rotation?

We have asked for a quote from Rick for a Celestron Omni 102 and an iOptron Minitower Pro. The iOptron MT Pro gets a good review from Ian Morison and I remember him loving it and showing it off at a 'show and tell' at the astro club, he was using it with a Takahashi 130.
Field rotation & orientation is the only real issue here.

I have an MT Pro, I like to use it for outreach because it's so easy to carry & set up compared with an equatorial with similar load handling capability. It would be fine for solar imaging except for the extra hassle that working out field orientation poses, and for the fact that field rotation makes mosaicing difficult & effectively rules out time lapse / video work.

In my experience a Tak 130 might be a bit much for a MT Pro (unless the wind was really calm) but it works well with a 110mm f/7 apo.


Pedro

Re: Ca K telescope

Post by Pedro »

Very interesting thread.

For Ca-K imaging I use two different apo refractors with excellent results:

1- TV101 F/5.9 @ F/10 + LUNT1200 CaK module
2- IKHARUS 102 F/7 @ F/10 LUNT1200 CaK module

Pedro


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Re: Ca K telescope

Post by swisswalter »

Hi Hubby and wife of it

I'm not having any problems with all my 13 scopes using a Cak filter of the KLUNT type. The best results I get with the bargain scopes ;-). Take a week off, travel to switzerland and get a cheap scope ? Make sure to discuss the sight seeings with Mark and his wife ;-)


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Re: Ca K telescope

Post by TheHubby »

Well everyone, I've made a start and ordered the filter.

The Lunt LS18CaKMDd2 calcium approach for refractors up to 102mm opening - with 90 ° deflection - with B1800 blocking filter.

It's going to take 3 weeks to arrive by which time I will have hopefully settled on the scope and mount by then.

(I must admit I nearly ordered the Ha B1800 filter by accident as they nearly have the same name but Alexandra insisted on checking the order before I made the order)

The Hubby.


Negative comments welcome to aid learning, as competing with Alexandra on her old borrowed equipment means I will always be 3 steps behind.
astrodanco

Re: Ca K telescope

Post by astrodanco »

Only three weeks. You lucky dog. I waited many months.


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Re: Ca K telescope

Post by swisswalter »

Hi Hubby

great. But the article number you mentioned is the B1800 :?


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Re: Ca K telescope

Post by marktownley »

Fun times ahead in Cheshire! :)


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Re: Ca K telescope

Post by marktownley »

Simpliest Fraunhoffer refractors of smaller apertures and very long F/D, at least F/10 and also they need to be severely UNDERcorrected for green light.

Hi Valery, is there a 'list' anywhere that would tell us the telescopes that were undercorrected for green light?


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Re: Ca K telescope

Post by robert »

I want to repeat what has been said about all az mounts because it could be very disappointing to have a high quality CaK filter and good optics with it. It will suffer field rotation which will make high quality imaging impossible. Setting up an eq mount even very roughly is very much better.
Good luck
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Re: Ca K telescope

Post by Montana »

Thanks Robert, I don't have any problem imaging with the PST on my little alt/az mount, I have even done timelapse OK with it, so long as you don't suffer from sea sickness it's OK to watch :lol:

Alexandra


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Re: Ca K telescope

Post by marktownley »

Thanks Robert, I don't have any problem imaging with the PST on my little alt/az mount, I have even done timelapse OK with it, so long as you don't suffer from sea sickness it's OK to watch :lol:

Alexandra

I hear what you're saying, but at CaK wavelengths you have 1.6x the resolution for a given aperture compared to Ha. 100mm aperture has 2.5x the resolution of a 40mm, multiply these together and you are looking at a factor of 4 i.e. 4x less time for field rotation to become apparent compared to your PST. If you do plan to do any timelapse with this setup and CaK wavelengths field rotation will be apparent... Just something to be aware of...


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Re: Ca K telescope

Post by TheHubby »

I hear what you're saying, but at CaK wavelengths you have 1.6x the resolution for a given aperture compared to Ha. 100mm aperture has 2.5x the resolution of a 40mm, multiply these together and you are looking at a factor of 4 i.e. 4x less time for field rotation to become apparent compared to your PST. If you do plan to do any timelapse with this setup and CaK wavelengths field rotation will be apparent... Just something to be aware of...

My imaging knowledge is limited so I won't be doing timelapses.

I will give that job to Alexandra who can do that properly on the TEC140


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Re: Ca K telescope

Post by Valery »

[quote]Simpliest Fraunhoffer refractors of smaller apertures and very long F/D, at least F/10 and also they need to be severely UNDERcorrected for green light.

Hi Valery, is there a 'list' anywhere that would tell us the telescopes that were undercorrected for green light?

Hi Mark,

There is no such list of telescopes undercorrected in a green light. But I can tell you, that MOST of chinese refractors are under corrected. So, they have better, than normal refractors, correction in a very deep violet.
As more your refractor is under corrected in green, as better for CaK.
Some years ago I bought such severe under corrected (in green!) objective 120mm F=1000mm. It has very very good correction in a CaK line.


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Re: Ca K telescope

Post by solarchat »

I've never seen this in any refractor and don't know how you can under correct a lens . But, I'm not mechanically or optically inclined. I do know I've never noticed any fringes in any single wavelength telescope application.


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