Search found 86 matches
- Mon Oct 30, 2023 8:04 am
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: Lunt BF400 modification.
- Replies: 3
- Views: 1399
Re: Lunt BF400 modification.
It's a modification that I have made about 10 years ago and which I have illustrated in an Italian forum in 2016 (modification then made by various other people in Italy)... https://www.binomania.it/phpBB3/viewtopic.php?t=8371 The advantage of the modification can be seen, compared to the small 4 mm...
- Sat Oct 28, 2023 7:34 am
- Forum: Solar Scope Modifications
- Topic: Lunt 40 mod basics.
- Replies: 24
- Views: 3631
Re: Lunt 40 mod basics.
Fortunately, the distance between the two collimator lenses (with the etalon in between) is not critical. With commercial lenses (i.e. not specially designed) the closer the lenses are the better the quality, however, as can be seen from the optical calculation images attached (objective diameter 15...
- Fri Oct 27, 2023 6:46 pm
- Forum: Solar Scope Modifications
- Topic: Question about H-alpha double stacking
- Replies: 37
- Views: 3822
Re: Question about H-alpha double stacking
Nice to hear, i might adopt parts of the design for my own tilters im planning to have done in a machine shop. What did you use as center part / filter holder, or was that selfmade too? The central part is a simple self-built aluminum cylinder, turned and milled (also to insert the small magnet). T...
- Fri Oct 27, 2023 2:11 pm
- Forum: Solar Scope Modifications
- Topic: Question about H-alpha double stacking
- Replies: 37
- Views: 3822
Re: Question about H-alpha double stacking
Yes, the functioning is perfect, precise and very sensitive (and also economical, if one has good manual dexterity: there is only the modest cost of the Baader ring and the small knob). Soon I will test the insertion of the BF 1800 Lunt filter into this tilting. I think that the fine adjustment (ins...
- Thu Oct 26, 2023 10:46 pm
- Forum: Solar Scope Modifications
- Topic: Question about H-alpha double stacking
- Replies: 37
- Views: 3822
Re: Question about H-alpha double stacking
- Thu May 18, 2023 7:17 pm
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: Differences between Lunt BF's.
- Replies: 28
- Views: 7497
Re: Differences between Lunt BF's.
Thanks Bob, everything correct and flawless. Naturally, the transmission of absorption filters depends also on the thickness, but, with the same thickness, no production tolerance of Schott BG38 glass can justify the difference in luminosity complained of by Gus (one Stop). The fact is that the two ...
- Wed May 17, 2023 4:38 pm
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: Differences between Lunt BF's.
- Replies: 28
- Views: 7497
Re: Differences between Lunt BF's.
Hello, I read this topic with much interest and surprise. The surprise is that I can't understand how a company like lunt can produce two articles that are supposed to do the same thing and which instead have such different results. In these years I have built 4 solar telescopes with Lunt etalons of...
- Fri May 12, 2023 11:15 pm
- Forum: Solar Scope Modifications
- Topic: Simulation of Airylab f/27 telecentric in near-UV
- Replies: 7
- Views: 1857
Re: Simulation of Airylab f/27 telecentric in near-UV
Christian, if you want to test a good self made telecentric, try this project of mine. I made it and it works great (3.3X). By changing the position of the three lenses it is possible to have all magnifications from 2X (if I remember correctly) to 5X. In the image, at the top, the spots relating to ...
- Tue Jan 04, 2022 7:12 pm
- Forum: Solar Scope Modifications
- Topic: Re: The Double pass idea...
- Replies: 16
- Views: 9621
Re: The Double pass idea...
Hello my tests on this subject are over. I have come to the conclusion that this double stack system CANNOT work, neither with a non-polarized prism and neither with a polarized prism and lambda/4 delay plate. The fact is that we have always thought about the matter by looking only at the beam split...
- Wed Feb 26, 2020 7:17 am
- Forum: Solar Scope Modifications
- Topic: 150mm/Lunt35/Coronado BF15 mod
- Replies: 48
- Views: 29532
Re: 150mm/Lunt35/Coronado BF15 mod
Yes. In a plane-concave lens of -300 mm focal length, the concave face is easily visible.
In any case, see the face for reflection. The plane face shows the reflection of the same dimension as reality. In the concave face all is much smaller.
In any case, see the face for reflection. The plane face shows the reflection of the same dimension as reality. In the concave face all is much smaller.
- Wed Feb 26, 2020 6:49 am
- Forum: Solar Scope Modifications
- Topic: 150mm/Lunt35/Coronado BF15 mod
- Replies: 48
- Views: 29532
Re: 150mm/Lunt35/Coronado BF15 mod
Carbon60, What you have done is correct. The best positioning of your plano-concave lens is what you can get experimentally after correctly putting the Lunt 35 (only complete Lunt 35) in focus at infinity. In this way it is certain that all the rays that come out of the plano-concave lens and enter ...
- Wed Feb 26, 2020 6:41 am
- Forum: Solar Scope Modifications
- Topic: 150mm/Lunt35/Coronado BF15 mod
- Replies: 48
- Views: 29532
Re: 150mm/Lunt35/Coronado BF15 mod
I wonder if separating binocular objectives would provide suitable plano concave lenses at much lower cost? No, Rusted, this is unfortunately not possible. The simplest solution is to buy the two simple lenses, flat concave and flat convex. The other solution is to design and build custom lenses wi...
- Wed Feb 26, 2020 6:19 am
- Forum: Solar Scope Modifications
- Topic: 150mm/Lunt35/Coronado BF15 mod
- Replies: 48
- Views: 29532
Re: 150mm/Lunt35/Coronado BF15 mod
Sorry Carbon60, You're right, I hadn't noticed the latest messages and I limited myself to the scheme of your drawings. In any case, my message was the pretext to let know that simple, concave and convex lenses, even with long focal lengths, and at a good price, can be found by searching the interne...
- Tue Feb 25, 2020 1:35 pm
- Forum: Solar Scope Modifications
- Topic: 150mm/Lunt35/Coronado BF15 mod
- Replies: 48
- Views: 29532
Re: 150mm/Lunt35/Coronado BF15 mod
As Valery has already written, the system use a scheme with internal collimation. The scheme of Carbon60 is not very different from this, lunt-tal_100.jpg with the only difference that he has kept, as a positive lens, the original achromatic lens of the Lunt 35, and therefore had to look for only th...
- Mon Jan 13, 2020 6:57 am
- Forum: Solar Scope Modifications
- Topic: Is this possible?
- Replies: 2
- Views: 4827
Re: Is this possible?
Hello, If you want to use the etalon of the Lunt LS60, If it is the model with a single objective lens you have only one solution: you have to change the two collimation lenses, the one in front (negative) and the one behind ( positive) of etalon. Sorry. Read here http://solarchatforum.com/viewtopic...
- Tue Mar 05, 2019 12:27 pm
- Forum: Solar Scope Modifications
- Topic: lunt 50 mod
- Replies: 35
- Views: 19517
Re: lunt 50 mod
If it can interest someone ... Here are the individual lens of 42 mm diameter f: -300 and f: +300 in my etalon Lunt 35. lunt_35_mod.jpg Here is the simulation of the quality of this collimator with three different objectives. Perfect lens 50/540 1_perfect_lens_50_540.jpg edmund50/500 achromatic lens...
- Mon Mar 04, 2019 7:44 am
- Forum: Solar Scope Modifications
- Topic: lunt 50 mod
- Replies: 35
- Views: 19517
Re: lunt 50 mod
Hello, many thanks for the information. Therefore the Lunt 50 Ha has an achromatic objective, and the image I posted was misleading. On the contrary, the lunt 60 Ha has a single lens lens, as it is clearly written in this image lunt_60.jpg Some time ago I wanted to buy a Lunt 60 Ha to use it to see ...
- Sat Mar 02, 2019 7:29 am
- Forum: Solar Scope Modifications
- Topic: lunt 50 mod
- Replies: 35
- Views: 19517
Re: lunt 50 mod
Hello GreatAttractor I found this image on internet... It is not a photograph, is a drawing that can not solve the mystery. It seems that only Lunt knows if the objective is single or achromatic :-) The number of reflexes is not significant, even a single lens produces two reflections, like a glued ...
- Fri Dec 21, 2018 7:30 am
- Forum: This is SolarChat !!
- Topic: Sol from the 18th of December 2018.
- Replies: 9
- Views: 1429
Re: Sol from the 18th of December 2018.
Just beautiful pictures! Compliments!
- Tue Nov 27, 2018 7:50 am
- Forum: Solar Scope Modifications
- Topic: Re: The Double pass idea...
- Replies: 16
- Views: 9621
Re: The Double pass idea...
Yes, sure.
A 25x25 mm beam-splitter Edmund, NOT polarized, costs only $ 220 and therefore has an affordable price. Who has a PST can certainly experience it.
A 25x25 mm beam-splitter Edmund, NOT polarized, costs only $ 220 and therefore has an affordable price. Who has a PST can certainly experience it.
- Fri Nov 23, 2018 10:40 am
- Forum: Solar Scope Modifications
- Topic: Re: The Double pass idea...
- Replies: 16
- Views: 9621
Re: The Double pass idea...
Hi As I have already written, despite negative experiences of other amateur astronomers more competent than me (even a German guy who deals with professional Optics), also I, few months ago, I have decided to experiment the possibility of making a double stack with a beam splitter cube. There are ma...
- Fri Nov 23, 2018 8:06 am
- Forum: Solar Scope Modifications
- Topic: optical contact experiments? Anybody?
- Replies: 4
- Views: 3976
Re: optical contact experiments? Anybody?
Hello TheSkyBurner I and you belong to the same category of people who like to experiment and who are sometimes optimistic about the feasibility of a project. It is normal that sometimes the project can fail. Not necessarily a failed project is a failure. On the contrary, a failed project is useful ...
- Wed Nov 21, 2018 7:29 am
- Forum: Solar Scope Modifications
- Topic: optical contact experiments? Anybody?
- Replies: 4
- Views: 3976
Re: optical contact experiments? Anybody?
Hello I'm not very expert, but two years ago I also thought about building an etalon in my home. I had two optical windows calibrated with correction on all sides of lambda/20. I thought about aluminising one side of every window with 95-99% reflection. I did not have problem doing this, I asked an ...
- Tue Sep 04, 2018 10:35 am
- Forum: Solar Scope Modifications
- Topic: lunt 50 mod
- Replies: 35
- Views: 19517
Re: lunt 50 mod
After a long time, during which no one knew if the Lunt 50 had a lens with a single lens or an achromatic lens, I discovered from this image lunt 50.jpg that even the Lunt 50, like the Lunt 60., seems to have a objective with single lens, and therefore the use of the Etalon of the Lunt 50, together ...
- Tue Aug 28, 2018 5:32 am
- Forum: Solar Scope Modifications
- Topic: Re: The Double pass idea...
- Replies: 16
- Views: 9621
Re: The Double pass idea...
Hi TheSkyBurner,
because we are trying to do the same thing, I with pessimism and you with optimism, we stay in touch. In the coming days I can put some pictures of my experiment ...
because we are trying to do the same thing, I with pessimism and you with optimism, we stay in touch. In the coming days I can put some pictures of my experiment ...
- Mon Aug 27, 2018 5:38 am
- Forum: Solar Scope Modifications
- Topic: Re: The Double pass idea...
- Replies: 16
- Views: 9621
Re: The Double pass idea...
At what price? The fact remains that if your beam splitter is semi-polarized, the image and all the reflections are semi-polarized and it is enough that a reflection has the same angle of polarization of the image to make the project a failure. However I have not discouraged you in your work (I myse...
- Tue Aug 21, 2018 6:13 am
- Forum: Solar Scope Modifications
- Topic: Re: The Double pass idea...
- Replies: 16
- Views: 9621
Re: The Double pass idea...
The issue is much more complicated than you see it. It is not always possible to put a polarizer. In the system in question, removing the reflection is not unlikely that the image will be removed ... and even if the image will not be removed, its brightness becomes even lower ... and it is already l...
- Mon Aug 20, 2018 7:15 am
- Forum: Solar Scope Modifications
- Topic: Re: The Double pass idea...
- Replies: 16
- Views: 9621
Re: The Double pass idea...
Yes, this system is old, but I have not seen many experimental applications... most it is remained in the design phase ... I myself am working for a prototype, just for the curiosity to see if work well... As Zetner said, if the beam splitter prism is polarized, the system will NOT work. To work it ...
- Thu Apr 12, 2018 11:28 am
- Forum: Solar Scope Modifications
- Topic: A high quality telecentric 3X made by itself
- Replies: 15
- Views: 7006
Re: A high quality telecentric 3X made by itself
Hello I apologize for the delay... Speaking of my telecentric, I had written to marktownley that quality decreases a little in the calcium line ... In reality this is not true, what happens is that it is the disc of difraction that in the wavelength of the calcium is half of that in H-alpha ... but ...
- Tue Mar 27, 2018 1:58 pm
- Forum: Solar Scope Modifications
- Topic: A high quality telecentric 3X made by itself
- Replies: 15
- Views: 7006
Re: A high quality telecentric 3X made by itself
Hello Maktownley I have had the time to verify the quality of my telecentric in the Calcium line. With Zemax in "optimization" mode I verified that the best scheme is the same as with H-alpha. Of course, the quality deteriorates slightly, but is always good for a field of 0.15 °, which cor...
- Mon Mar 12, 2018 6:55 am
- Forum: Solar Scope Modifications
- Topic: A high quality telecentric 3X made by itself
- Replies: 15
- Views: 7006
Re: A high quality telecentric 3X made by itself
Hello Marktownley 1) Please note that this telecentric was born in the amateurs astronomers field for a telescope f: 10, to bring the focal ratio to f: 30 (3X), when the telecentric 3X Baader had not yet been released. 2) As someone else has already experienced, the focal ratio f: 30, for to make an...
- Mon Feb 12, 2018 6:57 am
- Forum: Solar Scope Modifications
- Topic: A high quality telecentric 3X made by itself
- Replies: 15
- Views: 7006
Re: A high quality telecentric 3X made by itself
Thank's. I add only some useful information (they are written in the images, but if one does not know Oslo or Zemax can not interpret it): the first negative lens must be placed just before the telescope's focus. In a 150/1500 telescope this distance is 86 mm for 3X, 92 mm for 3.3X and 113 mm for 5X...
- Thu Feb 08, 2018 12:29 pm
- Forum: Solar Scope Modifications
- Topic: A high quality telecentric 3X made by itself
- Replies: 15
- Views: 7006
A high quality telecentric 3X made by itself
Do you need a very high quality 3.3X or 3X telecentric and do you have the ability to build it? Here is my project for a telecentric suitable for a H-alpha Telescope f: 10 (I designed and built it for my 150/1500 mm h-alpha Istar). There are two projects, one of a 3.3X (OSLO) and one of 3X (ZEMAX), ...
- Thu Jan 25, 2018 8:12 am
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
Hello Merlin 66 I managed to do two small projects to be able to use the Lunt LS60 etalon with achromatic objectives. Both have two collimation lenses 30 mm diameter and -250 and +250 mm of focal. These lenses is it available in the Optosigma catalog at 25 $ each ...) The first project involves the ...
- Tue Jan 23, 2018 10:59 pm
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
For me a good solution is an achromatic 100 mm f: 10 lens (as Tal rs100). In this case (if the etalon of Lunt LS 60 is 30 mm in diameter) will be necessary to change the two original lenses of the etalon with a new pair of lenses of 30 mm in diameter and -250 mm and 250 mm of focal length (plano-con...
- Tue Jan 23, 2018 1:58 pm
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
If the Lunt internal etalon is 30mm diameter... nothing changes You can put two 30-40mm lenses with the same focal length of my Lunt 35 upgraded. Sorry, but I'm not sure I understood your question correctly. Here it is not a question of improving, but of maintaining the quality of the new objective....
- Tue Jan 23, 2018 12:54 pm
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
The two lenses required for to upgraded the Lunt LS60 with a big achromatic objective are two simple catalog lenses (about € 25 each). Their simplicity and particularity is that put in that position and in that orientation (plane / concave and convex / plane) DO NOT introduce spherical aberration. I...
- Tue Jan 23, 2018 8:26 am
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
The flu has passed ... but this time it was hard ... Summarizing... In solar telescopes with an achromatic lens, the lenses of etalon collimator system do not introduce spherical aberration and do not change the quality of the objective. Precisely for this reason it is possible to replace the object...
- Fri Jan 19, 2018 4:15 am
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
Sorry Merlin66, but I'm in bed from two days with a fever at 39 °... I hope to recover soon. Now I can not even reason...
- Wed Jan 17, 2018 9:06 am
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
No, in this case I have taken the etalon of the Lunt 35 (which is frontal to the telescope and is not inside the telescope, as it is for the Lunt 50 and the Lunt 60). My modification consists in placing the etalon of the Lunt 35 inside a new telescope with a greater diameter than 35 mm (i have taken...
- Wed Jan 17, 2018 8:32 am
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
Yes, there is an achromatic objective in the PST and that is why in the PST it is possible to replace the small 40mm lens with a larger one. In this case the quality at the center of the field remains unchanged, as can easily be verified with an optical calculation program. If instead the lens objec...
- Wed Jan 17, 2018 7:38 am
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
Unfortunately it's not like that. What you write may be good for an achromatic lens, but it's not good if the objective of the solar telescope is a single lens. Recently I read a topic in which a passionate Italian complained of a poor quality of the telescope obtained by putting an achromatic lens ...
- Tue Jan 16, 2018 3:23 pm
- Forum: Solar Scope Modifications
- Topic: Lunt 60 mod options??
- Replies: 21
- Views: 8226
Re: Lunt 60 mod options??
It's strange, it seems to me that the Lunt ls60 is equipped with a objective with only one lens, so it is not the most suitable instrument for a modification. To have a good quality with another (bigger) objective, it is necessary to replace the negative and the positive lens of the etalon collimato...
- Thu Nov 23, 2017 6:45 am
- Forum: This is SolarChat !!
- Topic: Lunt 50 - Single Stack / Double Stack Comparison 19th November
- Replies: 22
- Views: 4682
Re: Lunt 50 - Single Stack / Double Stack Comparison 19th November
Lots of people have- check out the mods section 👍 You're right, I have not seen those topics recently, ... but there are only a few people, compared to the dozens and dozens of those who used the PST Etalon part ... Now I also figured why: I thought that the etalon inside the Lunt 50 was same as Lu...
- Wed Nov 22, 2017 6:57 am
- Forum: This is SolarChat !!
- Topic: Sun 21 11 2017
- Replies: 11
- Views: 2055
Re: Sun 21 11 2017
Hello Pepe
it would be useful to know what instruments you have used...
it would be useful to know what instruments you have used...
- Wed Nov 22, 2017 6:50 am
- Forum: This is SolarChat !!
- Topic: Lunt 50 - Single Stack / Double Stack Comparison 19th November
- Replies: 22
- Views: 4682
Re: Lunt 50 - Single Stack / Double Stack Comparison 19th November
Thank you for your answer. I asked this information why I did not read this anywhere. My request is motivated by the fact that if it uses an achromatic lens, I do not understand why no one uses the etalon block of this instrument to mount it on a large diameter telescope, just as many did with the b...
- Tue Nov 21, 2017 9:09 am
- Forum: This is SolarChat !!
- Topic: Lunt 50 - Single Stack / Double Stack Comparison 19th November
- Replies: 22
- Views: 4682
Re: Lunt 50 - Single Stack / Double Stack Comparison 19th November
Hello marktownley
Sorry, I have a curiosity: the Lunt 50 does have an achromatic lens or a single lens?
Thank you
Sorry, I have a curiosity: the Lunt 50 does have an achromatic lens or a single lens?
Thank you
- Fri Sep 01, 2017 5:25 am
- Forum: Solar Scope Modifications
- Topic: What does a "blocking filter" consist of... ?
- Replies: 13
- Views: 7290
Re: What does a "blocking filter" consist of... ?
Please read this my message in a italian forum:
https://www.astronomia.com/forum/showth ... RIMA-PARTE
It is in Italian language, but you should be able to understand something with google translator ...
Antonello
https://www.astronomia.com/forum/showth ... RIMA-PARTE
It is in Italian language, but you should be able to understand something with google translator ...
Antonello
- Thu Mar 30, 2017 11:13 am
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: Lunt 35 B400 vs, B600
- Replies: 5
- Views: 4191
Re: Lunt 35 B400 vs, B600
Hello
Sorry, I know that the post is old, but perhaps this information can be useful to others ...
Sorry also for the text in Italian, but it is easy to translate with google translator ...
http://www.binomania.it/phpBB3/viewtopi ... 129&t=8371
Sorry, I know that the post is old, but perhaps this information can be useful to others ...
Sorry also for the text in Italian, but it is easy to translate with google translator ...
http://www.binomania.it/phpBB3/viewtopi ... 129&t=8371
- Fri Dec 23, 2016 7:24 am
- Forum: Solar Scope Modifications
- Topic: Astronomik IR Block filter as internal ERF
- Replies: 12
- Views: 6574
Re: Astronomik IR Block filter as internal ERF
Thank you for reply Antonello :-D I've read all your posts, here and in the others forum, I appreciate very much your tests about photografic filters, too bad it's too late for saving my money because after a week without answer I've bought a Baader Erf filter... The ERF Baader is a excellent filte...