SolarChat!

Hey all,

I think news has gotten around about the problems with Meade, financially, I wonder who may buy them up or how this will get handled? But, I'm also curious, what's the future of Solarmax series? It's always good to have competition. Anyhow, I'm really curious if anyone knows or has heard of anything regarding where the Solarmax series may go at this point? The SMII series are available as standalone etalons. The SMIII series seem to only come as a complete telescope, so if you get a single-stack, you cannot even buy the 2nd etalon later yet, it seems? Also, does anyone know if there is even a difference, quality wise or anything, between the SMII and SMIII series etalons at all other than their external look? I like the idea of two front mounted etalons in the future.

Curious!

Very best,

Hi Marty,

I've not heard anything about it since the initial announcement.

Mark

I read about Meade declaring bankruptcy but know nothing more. I have a SolarMax II 60 DS. It does quite well but I never have liked the idea of the central obstruction it has in the light path. A refractor should be unobstructed. I did not research well enough when I bought it or I would have probably gotten a Lunt LS 60Tha which is unobstructed. But even with the obstruction and sometimes uneven tuning the scope does well. I can generally see much of the detail seen in the NSO GONG images.

I hope Meade/Coronado does not go under. Still, Meade and for that matter Celestron are not the companies they once were. I have always preferred Celestron over Meade but Celestron has no equivalent of the Coronado line of scopes.

I considered a SolarMax III 70. I am curious myself whether it is much better. It certainly has a better focuser and the totally external etalons give it more flexibility.

Hi,

I have a SolarMax II 60 DS. It does quite well but I never have liked the idea of the central obstruction it has in the light path.

If I remember well Lunt has even 3 little discs in their light path.

https://luntsolarsystems.com/wp-content ... cope-3.jpg

https://luntsolarsystems.com/shop/solar ... ar-filter/

Thanks Rainer, I am learning all the time! I must be wrong about Lunt too. It is Solarscope that is unobstructed.

https://solarscope.co.uk/solar-telescopes/

It does quite well but I never have liked the idea of the central obstruction it has in the light path. A refractor should be unobstructed.

An etalon is a filter, not a telescope. Etalons are quite sensitive to thermal variations of both the gap spacers and etalon plates themselves. A central (or other pattern) of spacers for a large air-spaced etalon helps to improve thermal stability and contrast performance by ensuring the uniformity of the etalon gap across the etalon diameter through changing temperature conditions:
Exaggerated depiction of central spacer patent for Coronado Instrument Group for improved solar etalon thermal stability.

https://www.cloudynights.com/topic/6226 ... try8658155

Moreover, a small central obstruction can actually improve optical performance of certain levels of detail, especially small high contrast detail:

https://www.telescope-optics.net/obstruction.htm

https://www.telescope-optics.net/mtf.htm

Bob,

Thanks for the info. I am used to nighttime observing which does not require etalons. As a general rule anything in the light path reduces contrast. The smaller the better. None is best. I actually downsized the diagonal mirror in my old RV-6 Dynascope years ago to push an already great performer to better levels. The scope already had excellent optics and by reducing the diagonal to a size which is just big enough to catch the entire light cone gives performance probably only a little short of an apochromatic refractor the same size. I guess I am just not used to a refractor with any kind of obstruction in the light path. Still, the SM 60 does well.

James

Hi James,

At 60-70 mm, an unobstructed etalon can perform quite well. But your minimally obstructed 60 mm will likely do just as well, and the wavefront effects of the obstruction will likely be indistinguishable from an unobstructed etalon, especially given daytime seeing rarely gets to diffraction - limited levels.

Beyond a certain point, even fused quartz etalon plates begin to have significant deformations over their larger surface areas due to non-zero CTE, and these need to be mitigated via additional measures to ensure plate parallelism and gap uniformity, and tuning ability. The 100 mm SolarScope etalons needed much better protection from thermal "extortion" compared to an obstructed Coronado SM90s. They would often start out being completely off-band, and could take more than an hour to get close - but never really quite got there:

Using an additional Baader DERF with the OEM Solarscope helped tremendously, but the SM90s to my eye retained a slight edge:

Solar Scope may have since addressed this, but if not I would consider a Baader DERF a mandatory accessory for their 100 mm etalon.

Using an additional Baader DERF with the OEM Solarscope helped tremendously, but the SM90s to my eye retained a slight edge:

Hi Bob,

Interesting. What does it mean in the above quote ? Two ERF or one ERF substituted by another one.

My double stack Coronado SM 60 has only one ERF. I took out the second ERF of the lower Etalon and I gained contrast and lower exposure times ...

Rainer

Hi Rainer,

It means I added a Baader DERF to the etalon assembly, which already included the Solar Scope OEM RG630 ERF with some IR blocking.


The OEM Solar Scope ERF apparently has significant IR leakage, which exacerbates the thermal instability of the 100 mm etalons (no central spacer) which I and others have noted.


A Baader DERF compliments the OEM Solar Scope ERF almost perfectly, ensuring little if any near IR reaches the etalons, and greatly mitigated the thermal instability:


Your Coronado SM 60's have a central spacer to mitigate thermal instability, and work well for the etalon. However, the Coronado RG630 ERF has no IR blocking, which can cause excessive thermal stress to the ITF of the blocking filter, and I would employ an additional IR blocking filter at the nose of the blocking filter itself to reduce the thermal loading and cycling that usually results in ITF degradation.

Bob Yoesle wrote: ↑Mon Jan 13, 2020 7:49 pm Hi Rainer,

It means I added a Baader DERF to the etalon assembly, which already included the Solar Scope OEM RG630 ERF with some IR blocking.


DSF100 v SM90DS DERF comp.jpg


The OEM Solar Scope ERF apparently has significant IR leakage, which exacerbates the thermal instability of the 100 mm etalons (no central spacer) which I and others have noted.


Sol-ERF-lin.jpg


A Baader DERF compliments the OEM Solar Scope ERF almost perfectly, ensuring little if any near IR reaches the etalons, and greatly mitigated the thermal instability:


Baader-D-ERF.jpg


Your Coronado SM 60's have a central spacer to mitigate thermal instability, and work well for the etalon. However, the Coronado RG630 ERF has no IR blocking, which can cause excessive thermal stress to the ITF of you blocking filter, and I would employ an additional IR blocking filter at the nose of the blocking filter itself to reduce the thermal loading and cycling that usually results in ITF degradation.

Hi Bob,

Ah thank you. You killed more from the infrared ...

Rainer

Yes, exactly.

At sea level, over 50% of the energy from the Sun lies in the near IR. The combination of the two ERF's essentially removes everything out to 2500 nm, where the atmosphere then blocks most everything beyond.


The larger Solar Scope filters - lacking a central spacer to maintain etalon gap parallelism - are particularly vulnerable to this IR. Blocking this IR at the etalon seems to be essential. And though I employed the DERF for ITF protection, even my SM90's with a central spacer seem to perform better due to the presence of the DERF. Note the "naked" RG630 ERFs used by Coronado and DayStar are completely transparent to this IR.

This is unfortunate that there's no clear road map future for Meade since they have Coronado and that's the only other affordable competition to Lunt. Also, they seem to be the only ones offering affordable front mounted etalons. Also, very disappointing that currently SMIII series options can only be had via buying the entire package together, as one cannot source a single etalon to add later.

If Meade goes down, I wonder who would buy them out and add their own spin on solar? If Orion bought them, sheesh, the costs would be silly.

Very best,

There's the Celestron brand owners perhaps...

Wouldn't it be poetic justice if Lunt bought back their original patents and possibly production infrastructure for pennies on the dollar at auction?

Hi,

I just read this

https://www.skyandtelescope.com/astrono ... ankruptcy/

and this

https://www.telescope.com/assets/docume ... 1-2019.pdf

¿?¿?¿?

Bob Yoesle wrote: ↑Fri Jan 17, 2020 2:12 pm Wouldn't it be poetic justice if Lunt bought back their original patents and possibly production infrastructure for pennies on the dollar at auction?

It would!

But then less competition

Very best,

If you look at the original suit and judgement, Meade is only the first to go through bankruptcy protection....Celestron and Sky Watcher are also named so this may go to the next step sadly. https://www.telescope.com/assets/docume ... 1-2019.pdf

I do think Meade and hopefully the other two will also survive but are slapped down.
What this means for the amateur astronomy community can be major. Will this eliminate those three major players or severely hamper their operations. And if they survive will this reduce the types of products and number of options and drive the price up for consumers.

Bottom line....perhaps there was collusion and price fixing.....and lawyers got involved as they saw money and deep pockets. BUT I suspect the people that will be hurt by this are consumers who will now have less choice and costlier products.

Unfortunately its just a business to the business people.

The same way medicine is just business for a supplier, but required for the end-user.

As we measure ourselves in the billions, each individual matters less to larger entities like corporations, or business in general.

I hope they all survive. The end-users are indeed the ones that hurt. In an already declining interest world....

Very best,

It seems self-destructive if Orion sues Celestron. Synta owned Celestron is a major supplier of Orion Telescopes and Binoculars. Orion makes nothing on it's own.They are basically just a store. A brand name.

Meade should die. It did enough damage to other astrobusineses and astrocommunity.

DeepSolar64 wrote: ↑Wed Jan 29, 2020 7:15 pm It seems self-destructive if Orion sues Celestron. Synta owned Celestron is a major supplier of Orion Telescopes and Binoculars. Orion makes nothing on it's own.They are basically just a store. A brand name.

In the corporate world lawsuits are used as negotiations leverage.

Valery wrote: ↑Mon Feb 03, 2020 7:01 pm Meade should die. It did enough damage to other astrobusineses and astrocommunity.

Such as?