Search found 86 matches

by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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

KMH wrote: Fri Oct 13, 2023 6:47 pm Interesting....
What would you use as a tilting device?
Kevin
See this, if it helps
viewtopic.php?p=156165#p156165
by antonello
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 ...
by antonello
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...
by antonello
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 ...
by antonello
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...
by antonello
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.
by antonello
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 ...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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 ...
by antonello
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 ...
by antonello
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!
by antonello
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.
by antonello
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...
by antonello
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 ...
by antonello
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 ...
by antonello
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 ...
by antonello
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 ...
by antonello
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...
by antonello
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...
by antonello
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 ...
by antonello
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 ...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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), ...
by antonello
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 ...
by antonello
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...
by antonello
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....
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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 ...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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...
by antonello
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
by antonello
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
by 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
by antonello
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...