Search found 86 matches

by antonello
Mon Aug 27, 2018 5:38 am
Forum: Solar Scope Modifications
Topic: Re: The Double pass idea...
Replies: 16
Views: 9633

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: 9633

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: 9633

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: 7014

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: 7014

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: 7014

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: 7014

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: 7014

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: 8236

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: 8236

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: 8236

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: 8236

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: 8236

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: 8236

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: 8236

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: 8236

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: 8236

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: 8236

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: 4683

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: 4683

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: 4683

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: 7296

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: 4194

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: 6579

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...
by antonello
Thu Dec 22, 2016 8:14 am
Forum: Solar Scope Modifications
Topic: Astronomik IR Block filter as internal ERF
Replies: 12
Views: 6579

Re: Astronomik IR Block filter as internal ERF

Hello Merlin66 Yes, the use of a Baader H-alpha 35nm as ERF is a good solution, more or less like the others on this chart attached. The Baader H-alpha filters have quality Lambda/2 as the B + W. I have tested (in may samples) that the standard Baader filters have quality lambda/2 as photographic fi...
by antonello
Wed Dec 21, 2016 10:41 am
Forum: Solar Scope Modifications
Topic: Astronomik IR Block filter as internal ERF
Replies: 12
Views: 6579

Re: Astronomik IR Block filter as internal ERF

Hello Vicchio I suggest you read this post (in Italian), with many apologies to all those who do not understand Italian language. http://www.binomania.it/phpBB3/viewtopic.php?f=160&t=8269&start=10 In this post I recommend the use in a small telescopes two photographic filters like ERF (RG630...
by antonello
Mon Nov 14, 2016 7:04 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Dream come true!
Replies: 113
Views: 50397

Re: Dream come true!

Hello Bob Yes, the two lenses (in a system with a plano concave and a plano convex lens standard) must be placed as in the drawing, with the plano surfaces facing outward for each optic. Only so the quality of the telescope it is maintained. Hello Christian Yes the lens has an f: 6.6, but this is th...
by antonello
Thu Oct 27, 2016 11:37 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Dream come true!
Replies: 113
Views: 50397

Re: Dream come true!

Hello Christian I designed the collimator with OSLO and optimized with Zemax so that none of the surfaces of the lens was flat, then I built the lambda/10 lenses from an important national industry. The system is expensive, but it is perfect. This is the spots diagram with a perfect 150 mm f:10 lens...
by antonello
Thu Oct 20, 2016 7:11 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Dream come true!
Replies: 113
Views: 50397

Re: Dream come true!

Hello Bob Also I have had a dream for a long time and I worked for achieve it. For this purpose I have built a slight Truss (see picture 1) 1.jpg for a 150 mm H-alpha Istar lens. After, I have purchased a Lunt Etalon, the model for 60 mm Double stack, for to put it inside the telescope. For this pur...
by antonello
Fri Jul 22, 2016 10:58 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader D-ERF Question
Replies: 15
Views: 9208

Re: Baader D-ERF Question

Hello to all, Unfortunately, I have no measurement of photographic filters ... Christian, many thanks for your answer. I am a technician of a professional astronomical observatory in Italy … The Zygo of my Institute is set, from several months, for the control of a 300 mm diameter camera for a sate...
by antonello
Mon Jun 06, 2016 7:26 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader D-ERF Question
Replies: 15
Views: 9208

Re: Baader D-ERF Question

I was hoping to get a scientific answer to my question and instead I received only praise of Baader products, as if I had written that the Baader products are not good ... But I DO NOT wrote that the Baader products are not good… There are at least two good scientific answers to my question. The fir...
by antonello
Sat Jun 04, 2016 6:38 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader D-ERF Question
Replies: 15
Views: 9208

Re: Baader D-ERF Question

Camera filters are usually not 1/4 wave on transmission. Mark W. In fact, I have read that they are machined 1/2 wave ... and what does that mean? I have done many tests with 60 mm and 100 mm lenses and I did not see any difference between the B + W filters and ERF Baader filter, then the differenc...
by antonello
Tue May 31, 2016 10:22 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader D-ERF Question
Replies: 15
Views: 9208

Re: Baader D-ERF Question

Hello Christian I have realized some ERF using a combination of two photographic filters: B+W 091 (RG630) and a B+W 486 (UV-IR Cut) bought used at cheap on Ebay. I have also measured the transmission (attached), compared to Baader and Lunt ERF. Looking into the telescope I do not see the quality dif...
by antonello
Mon May 30, 2016 10:32 am
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

Merlin I read the messages of BYoesle: http://www.cloudynights.com/topic/537136-tilt-tuning-etalon/ with great interest. Therefore "Jaquinot spot" (that I did not know before) it is only synonymous of Sweet spot ... Valery I think it is useful to point out that "Sweet spot = De / Do&q...
by antonello
Tue May 24, 2016 6:33 pm
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

http://www.astrosurf.com/viladrich/astro/instrument/solar/FP-no-tele.htm This is an excellent reference for those interested in etalons and their performance. OK Merlin, I have found the reference to Jacquinot spot: http://www.cloudynights.com/topic/537136-tilt-tuning-etalon/ Now I study this commu...
by antonello
Tue May 24, 2016 12:18 pm
Forum: Solar Scope Modifications
Topic: Just blocking filters.
Replies: 5
Views: 3275

Re: Just blocking filters.

Ghost-Fire wrote:Has anyone experimented imaging with just your blocking filter and erf?
Why you thought it was done by many people, for example:

http://www.considine.net/dgroski/halpha/

However, the quality of an ERF-ETALON-BF system is superior ...
by antonello
Tue May 24, 2016 11:16 am
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

Antonello, I don't have access to my computer to supply the links I have... If you search this forum on "sweet spot" and look for this discussions in early 2015 ( Bob Y. Etc) you should find the formula and discussions on the Jaquinot spot. Merlin Thank you, but I already know of these do...
by antonello
Fri May 20, 2016 5:27 am
Forum: Solar Scope Modifications
Topic: First PST Mod Questions and Check
Replies: 6
Views: 4048

Re: First PST Mod Questions and Check

5) I will be using a Lunt ERF for this Mod. Is the transmission profile similar for the Lunt as the Baader? Hello I was in charge of recent solar astronomy and in our laboratory I have done many tests on solar filters (BF, ERF, etc.). This is the graph of the transmission curve of three different E...
by antonello
Thu May 19, 2016 5:00 pm
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

Thank you Merlin, it is always nice to learn.
Thank you for references. I will look.
by antonello
Thu May 19, 2016 4:06 pm
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

My English is not good to understand what you're thinking. My approach is more experimental: in my collimated system with etalon (a Lunt etalon 60 mm) inside my F:10 telescope, 100 mm f:1000 there is an image area (0.5 °) in which I see the sun in H-alpha. Outside this circle (sweet spot) the image ...
by antonello
Thu May 19, 2016 3:38 pm
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

OSLO (as zemax) does not determine the sweet spot...
Oslo allows you to calculate the angle of the collimated rays inside the etalon. Many larger is this angle, respect to optical axis, and many small is the sweet spot. Elementary.
by antonello
Thu May 19, 2016 3:25 pm
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

... What I have written is a result of the analysis with an optical design software .... (OSLO)
by antonello
Thu May 19, 2016 10:21 am
Forum: Solar Scope Modifications
Topic: F11 PST scope
Replies: 18
Views: 6072

Re: F11 PST scope

Perhaps it is better to be more specific At the same focal, closing the opening to the objective, all extrassial rays, inside a collimated etalon, continuing to have the same angle. So the sweet spot remains the same. In other words: A 80 mm vixen F: 11 has the same sweet spot of 40 mm F.22. The Swe...
by antonello
Fri May 22, 2015 6:24 am
Forum: Solar Scope Modifications
Topic: PST mod1 on a C8 without ERF
Replies: 7
Views: 3224

Re: PST mod1 on a C8 without ERF

we have already a definition > 100mm scope! This is exactly what I wanted to say... Having a 200 mm and see as a 100 mm is not (for me) pleasant :( . (I have also a telescope Tal 100 mm, with internal etalon lunt, and I know exactly what I can do with him). Naturally, my speech was not for belittle...
by antonello
Thu May 21, 2015 7:03 pm
Forum: Solar Scope Modifications
Topic: PST mod1 on a C8 without ERF
Replies: 7
Views: 3224

Re: PST mod1 on a C8 without ERF

Yes, I think you're right... I had not checked the transmission of a photographic Baader Astrosolar (T = 0.00015) ...
Unfortunately, it is sad to see the noticeable drop in quality with the three filters (but also with 5 filters, I think...) ...
DSobserver wrote: I doubt : the astrosolar will block to much light!
by antonello
Thu May 21, 2015 5:25 pm
Forum: Solar Scope Modifications
Topic: Solar Continuum - leaky filter mount
Replies: 8
Views: 1936

Re: Solar Continuum - leaky filter mount

I did not write that this is right ... :-) I have just written "it is normal": all production is so, not only your filter. The problem can be solved only by Baader doing a little less thin the ring block in the filter holder ... or placing a new and bigger stop ring ... as you did. :-) Ant...
by antonello
Thu May 21, 2015 6:45 am
Forum: Solar Scope Modifications
Topic: Solar Continuum - leaky filter mount
Replies: 8
Views: 1936

Re: Solar Continuum - leaky filter mount

It is a normal thing... The filters are placed in a special plate which covers a little the periphery of the filters, before treatment under high vacuum ... I have the filter 1.25 " and also to 2" inches. Both of the filters are not treated up to the edge, however, in the model by two inch...
by antonello
Thu May 21, 2015 6:14 am
Forum: Solar Scope Modifications
Topic: PST mod1 on a C8 without ERF
Replies: 7
Views: 3224

Re: PST mod1 on a C8 without ERF

Sorry, maybe you get a better result by putting in front to telescope an astrosolar Baader photographic sheet and behind, before the PST, an ERF by two inches?
Antonello
by antonello
Sun May 03, 2015 3:27 pm
Forum: Solar Scope Modifications
Topic: Barlow F30?
Replies: 17
Views: 5324

Re: Barlow F30?

Thank you mdwmark I saw your ZEMAX project. Really many compliments for the excellent design with commercial lenses. From what I have seen everything has to work perfectly. Your telecentric barlow transforms in f: 32 an f: 5.56, and seems suitable for a specific telescope, in fact is 5.75X. Who need...