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Hello everyone!

I want to buy a 150 mm aperture solar telescope, to photograph prominences and active regions in more detail. As I live in Argentina, with the restrictions that my country imposes on imports, I cannot fail in the choice of equipment, since it would be impossible to return or exchange it and there is not much market to sell it used. That is why I turn to the experience of all of you so that you can advise me. The first telescope I thought of was a Lunt 152 f6, initially single stack and later buying a second etalon to have a double stack. The other option is a TS Optics 150 f8 apo doublet and use it with a 0.6 Angstrom SE Quantum filter.
Will I have a much higher image quality with the Quantum filter compared to the Lunt? The image of Quantum filters is more homogeneous than that of Quark filters?
What other things should I keep in mind?
My current equipment is a Coronado Solarmax II 90mm telescope (I use it mainly for full disk imaging) and a Sky Watcher Esprit 120 with a Quark Chromosphere filter for details.
Thanks a lot!

Hi there!

If you already have a good quark, assuming you're happy with it I would get a 150/8 doublet.

Who knows whether the Quantum will be better than the Quark - you would think so, but knowing what Daystar is like I wouldn't assume anything.

Mark

Mmm I was going to say if you have difficulty with returns, then I would avoid Daystar, but then if you are happy with your Quark then stick with it, don't tempt fate.

Alexandra

I would do as said by Mark and Alexandra. If you are happy with the Quark, go for the 150 mm f/8 and possibly a Baader ERF.

I would read the following thread. Just because you pay A LOT for a solar product does not mean it will be trouble free. If you are happy with your quark, I would stay with it.

viewtopic.php?f=10&t=29454

As advised I will use the Quark too. Be familiar with that combo. To be fair I have seen Quarks from very bad to excellent... If your Quark is good - keep it. I do have a Quantum SE 0.6 A filter. And I even have a test sheet. It is better than any Quarks I have tested. To be honest my concerns regarding Quantum filters are from this forum and some filters I have seen. Sometimes I had really been thinking about upgrading service to get a more narrowband filter. But to have an etalon from founder Del Woods - well I know for sure I will keep it.
It is the reason I have a SolarSpectrum 0.3 A filter now. 2 great filters. I will always recommend Marks filters.

Hola,

Te mandé un correo privado. Saludos

I would second the recommendation of SolarSpectrum filters. I love mine and have never read of a complaint

christian viladrich wrote: ↑Thu Apr 08, 2021 8:56 am I would do as said by Mark and Alexandra. If you are happy with the Quark, go for the 150 mm f/8 and possibly a Baader ERF.

Thanks Christian for your answer!!
It seems like a good option to go for a doublet and use my Quark.
One more question... What is the difference in image quality between a Lunt 152 f/6 and using a doublet with my Quark filter? Or rather how good are the etalons used by the Lunt 152? I am attracted to the versatility of the Lunt, since I could also use it to make full disk images and with a barlow to obtain details.

Thank you!!

Hi,

Does the 152 mm Lunt telescope come with a test sheet ?

rsfoto wrote: ↑Fri Apr 09, 2021 6:39 pm Hi,

Does the 152 mm Lunt telescope come with a test sheet ?

I have owned three Lunts (2 80 DS and 100 DS) and none came with test sheet

If you have a more than okay Quark - the single stack Lunt will not show more details - but you can image the full disk. Side by side my 0.6 A Quantum and a Bresser 127mm f9 doblet was a little bit better on surface details and stunningly better on prominences... A very good Quark at the same meeting did outperform all filters on surface details. But as you know, Quarks specifications can vary from a PE 0.2A to worser than a 0.7A SE filter.

Ljungmann wrote: ↑Fri Apr 09, 2021 8:21 pm If you have a more than okay Quark - the single stack Lunt will not show more details - but you can image the full disk. Side by side my 0.6 A Quantum and a Bresser 127mm f9 doblet was a little bit better on surface details and stunningly better on prominences... A very good Quark at the same meeting did outperform all filters on surface details. But as you know, Quarks specifications can vary from a PE 0.2A to worser than a 0.7A SE filter.

Thank you very much for your answer!
Could you compare your Bresser 127 with Quantum filter side by side with a Lunt 152? I was interested in what you say about the prominences, I thought that the Lunt having a larger aperture could show more detailed and bright images of them.

It can be tricky to say why a filter performes better. But transmission is one of the more delicate issues in a solid etalon system. Mica can behave in different ways. It is often not neutral in color. Homogeneity and transmission can do a lot in the contrast department. I have seen in a 0.4A SE Quantum filter with very low transmission and I was not impressed. My Del Woods mica 0.6A etalon has a very high transmission (people do say to me that its to bright and you need a neutral filter!) but I like it. It is one of the main reasons I can see a lot of delicate prominences and extremely lots of details too. The other thing is that it has 0 reflections and no ghost image. The background is black as in black. I think it all helps. But you never know what transmission your filter have before you actually look at the Sun for the first time.
It is one of the reasons I do like SS filters. Mark will always work around the transmission profile to get the optimised filter stack. It is easy to see it in my own 0.3A filter. And I think Del Woods did the same in the old Daystar days.

Hi,

First, I would say you need to get an idea of your seeing conditions. Taking a mica-spaced etalon to F30~F40 with a 150mm aperture requires excellent seeing conditions, even with a reducer. To even benefit this aperture's resolution potential you need around 1 arc-second seeing (slightly better than 1 arc-second would be far more ideal). Otherwise, in reality, you're losing resolution to whatever the seeing actually is. Thankfully you can aperture mask a refractor for this purpose if needed, but the focal-length remains so you are pushing very fine image scales often when seeing isn't supporting it.

If your Quark is good enough, stick with it. I would argue any etalon from Lunt will likely be superior to an average Daystar one and it will be a lot more fuss-free (no electronics, not mica-spaced, etc). A pressure tuned Lunt etalon would be a way better gamble of all options out there in my opinion.

Very best,