Friday, December 11, 2009

Hola from PERU!! (Part 1)

Here is an image of Rikki working out of her spacious office in Peru..

The following is a blog from Rikki talking about the move..

I have known Andy for about 8 years.

When he asked if I would like to work for him at Lunt Solar Systems I jumped at the opportunity. We had worked together at Coronado and I knew he had the vision and knowledge to make an amazing product and company.

There was one catch, however, I told him and the other owners that my husband and I were planning on moving to Peru in the next year to 2 years. He said “Well I’ll take you as long as we can have you.” Honestly I don’t think he thought we would go.

Peru…why Peru? My husband Jon was born in Peru. His family ran a Christian mission in the river basin of Pucallpa Peru. His father has retired from running the mission and Jon’s sister has taken over. There focus is on the kid in the community. Jon’s dad has a cattle ranch that he and Jon are now converting to housing developments.

When the time came and I let Andy and the guys know I was leaving we talked about me working remotely. Most of what I do is over the phone or online.

If you email of call Lunt Solar 99% of the time you will either be talking or writing to me.

So we set up a system that lets me log on to our accounting software remotely and a phone system that lets me talk with customers anywhere in the world.

And none of this would be possible if it weren’t for my eyes and ears (sometimes hands) in Tucson…Jen.....She is a life saver.

Wednesday, November 25, 2009

What's and Etalon, and How do I Make One?

For those who have googled "what's an etalon?" the returned results outlining complex looking optical equations, mathmatical relationships, and technical references probably didn't do much to answer the question. Unless you are an Optical Physicist of course. (I love that stuff)

An etalon refers to an interference type filter typically used in Solar Telescopes because of the desire for an ultra narrow bandpass.

An etalon is probably one of the simplest designs for an optical filter utilizing some of the most precise optical specifications. Due to it both being simple and the need for precision, there are many compromises that can influence the quality of an etalon filter.

An etalon is comprised of 2 flat and parallel optical surface that have been optically coated with a high reflective dielectric layer with the high reflector layer peaking at the desired bandpass point for best results. These optical surfaces are seperated by a gap. This gap can be either air or a solid material. The light resonates in the gap by internal reflection off the highly reflective layers on the surfaces. Thru interference at this gap, only light meeting the correct angle of incidence to the surface and is not "interfered with" can pass, all other light is lost.

The main parameters that define an etalon are:

Bandpass: This is the width of the curve that defines the transmitance of the filter at 50% of the total transmision of the filter. An etalon's transmission has a broad base and a sharp peak. Typically the peak transmission should be between 80-90%, so the bandpass of the etalon will be measured between the 40-45% points. For Solar applications it is generally accepted that the lower this number, the better. Typical Solar Etalons have a bandpass of <1.0.

Bandpass is a function of the gap size between the high reflector plates. The larger the gap size, the narrower the bandpass.

Bandpass is also a function of the reflectivity of the etalon high reflector plates. The higher the reflectivity, the narrower the bandpass.

Peak Transmission: In order to obtain good contrast it is important to maximize the peak transmission while minimizing the "out of band" transmission. To explain this statement, a surface that had zero reflectivity would have 100% peak transmission. However, because there is no reflectivity in the cavity, there is no interference, and thus, no filter (bandpass). A surface with 100% R would reflect all light before it entered the cavity, thus having zero T. The compromise is somewhere in between..

Peak transmission is a function of the reflectivity of the surfaces. The higher the R, the lower the peak transmission. (in reality it isn't quite that simple)

Free Spectral Range: The free spectral range is defined as the gap between the peaks of transmission plotted againt wavelength. Huh?? An etalon produces a "comb" of peak transmission across a broad range of the visible spectrum. This would be like a hair comb. One tooth of the comb would represent a peak transmission. This comb would then be missing about 12-14 teeth before the next peak transmission, or tooth. In our case the FSR is more than 10 Angstroms. This becomes important to our ability to block the unwanted peak transmissions utilizing simpler filters. The narrower the FSR, the harder it is to block the transmissions you don't want. Letting another leak transmission thru will wash out the details.

FSR is a function of gap size. The narrower the gap, the wider the FSR.

Optical Flatness and Parallism: Probably the most critical aspects of the etalon performance.... To put it simply, the better the flatness and the parallism, the better the etalon.
The quality of an etalon is very much the function of precision polishing and gap maintainance.
When it comes to the specification of a Solar Telescope I often hear the bandpass stated out as a matter of fact. However, this bandpass is typically the theoretical value of the system based on the known paramaters of reflectivity, gap size, and optical flatness. What one should realize is that bandpass is not the all defining specification of a quality system.
I could quite easily manufacture a 0.3A bandpass filter and everyone would be happy.. Right??
Not if it's performance was any factor.. An etalon with a peak transmission of 40% and a FSR of 4A is quite easy to manufacture. But I assure you, you wouldn't want it in your scope.
When it comes to Etalons there are typically a few things to look at.. The bandpass, is of course, of very high concern as long as all other aspects of the optical system have been addressed. An FSR of greater than 10A is required in order to prevent out of band leaks. (the camel peaking it's nose under the tent) a phrase I liked when I heard it.
Peak T is also important as long as it comes with a zero baseline. Signal to noise ratio is critical because it is what makes the brights bright, and the darks dark. No-one want to see a significant orange glow in the space around the Sun's image, this simply washes out the edge details.
Contrast is just as important as bandpass in my opinion. However, there really isn't any specification for contrast ratio.
End of Part 1
Next: How do we make them?

Etalons: External and Internal

Which is Better??

The defining difference between an External etalon vs an Internal etalon has typically been Price vs Performance... Well that gap is getting very narrow.

External etalons are used on the front of an existing scope, and the user typically asks that the etalon be full aperture. Internal etalons are situated internally to the scope, allowing for a full aperture objective to pass the light thru a smaller etalon due it being placed further down the optical path.

The basic rule of thumb for an etalon is the price is a function of the area. That adds up fast.

Another rule of thumb that I have heard is that the acceptance angle of an airspaced etalon is 0.5 degrees. What one should keep in mind is that, in any case, an etalon specified by surface reflection at the interface of the internal plates, thickness of gap, and gap medium only, will NOT perform to that optimal specification should there be anything other than collimated light passing thru it.

F30 does not apply specifically to airspaced etalons due to the higher index material utilized at the gap of the solid design. In most cases for solar this is solid material is Mica, and in some cases it is fused silica. All solid etalons that I have made for space flight have been fused silica.

The Sun is not a point source. In fact, the Sun is a very large extended source. It may look small at 93M miles away, but it is 865,000 miles in diameter. To put that in perspective, if the Sun were an objective and the front of your filter was the focal plane (I don't think we need to look at filter size in this example ;) the system would have an F107 ratio. That's still not entirely collimated..

Seeing the Sun at Sunset or Sunrise in relation to a distant mountain also puts it's size into perspective.

Even so, the best position for an etalon filter is on the front of the scope. However, this etalon is still compromised from ideal by the Sun's angle. These errors are small.
The use of tilt at the front etalon is simply a method of shifting the bandpass (the frequency of light passing thru the etalon). Due to the acceptance angle of the etalon, this tilt must remain very small. The more the tilt, the wider the bandpass becomes, and the non-collimated Sun angles begin to play a factor.

Tilting was introduced many years ago as a way of allowing etalons to be mass produced at slightly above the Ha line. They could then be tilted on line to accomodate the users changes in altitude and changes in barometric pressure at any given location. Without tilt, Solar Telescopes would be many times more expensive than they are today.

The move to internal etalons was done in order to bring the manufacturing costs of the Solar Telescopes down to less than 1k. By utilizing an etalon that was half the diameter of one required for the front, the cost of the etalon was cut by more than half. Even with the added cost of re-collimating and re-focus lenses, the system realized significant gains in affordability.

One of the huge benefits to internal etalons has been the fact that we only deal in one wavelength of light. This allows for the optimization of the internal lens system to remain fairly simple and straight forward. Ha! Right.. Simply aligning and collimating 4 optics now..

The evolution of internal etalons has taken several steps.
The original systems had internal fixed etalons that sat behind a re-collimating lens set (these lenses work to bring the light rays back to parallel). The light from the etalon was then re-focused back to the image plane.

These systems cannot compensate for changes in altitude and air pressure. Taking this system from sea level to 8,000ft would not work.

The next step is the introduction of some tilt. This works similar to the tilt on the front of a system. However, due to both off axis light rays that could not be re-collimated with a simple lens, and the angles created by the Sun's size, the etalon can only be tilted thru a fraction of a front mounted system. These etalons have been designed to be only very slightly higher than the Ha line so minimal tilt is required. Front mounted etalon designs can be used for this process, but recent innovations to coatings on the etalon cannot be used due to the new design's slightly narrower acceptance angle.

These systems maintain a very good flat field of narrow bandpass due to the optimization of the collimating set at Ha over about 80% of the entire field. Etalons with a theoretical bandpass of 0.65A are used, but are specified internally at 0.75A over the entire field due to the compromise of the ray angles. The center portion of these systems is typically better than 0.7A.

The current technology is the Doppler True tuning design.
The technology came about for the simple reason that tilted internal etalons are not optimized. The ideal design calls for an internal etalon (to reduce cost) in a perfectly collimated system, without the need for tilt, while also compensating for altitude and pressure changes (or being isolated from).
The new system may be simple, but it addresses 99% of all the relevant issues.

The incorporation of the air pressure system (see other blog entries for description of how this works ) has allowed us to improve the technology of the high reflector layers.
For a given optical system, we have been able to modify the design of the HR. We are still working on tweaks and changes, but have already seen some improvement to resolution, field flatness, and contrast. The new designs are moving in an area that provides for blacker backgrounds and sharper features. There's still room for improvement..

So which is better? External or Internal??

The jury is still out on that one. It is still a function of Price vs Performance.

The new evolution of internal design has certainly gone a long way to improving the performance of internal systems. However, the added cost of the pressure system has now made the external system seem more affordable.

In my opinion the best option is to buy as much double stack system as you can afford ;)

All kidding aside. Going with an internal PT system is probably the most ideal start. Buying a system that you know you can DS later without much problem is good. The dedicated system is fully optimized and ready to go. We are familiar with these systems and can help with technical issues. We test every system that goes out. I cannot test a Lunt Filter on Your scope. I cannot answer questions about in focus etc. for Your scope.

The removal of the tilting from the internal system is providing stunning results. The ability to Doppler Shift instantly to and away from you adds a 3D feel to the image that cannot be matched. This technology has certainly improved the dedicated system.

Now... What about all that tilt on the front??

The see-saw of performance is about to swing again. Lunt will be introducing the front mounted filter system with the Pressure Tune capability in mid next year (or maybe sooner ;). These systems will be manual control and also remote operable. For those that don't have 6 foot arms for your LS160F on that really long scope, this will certainly be a must.

Next blog: What is an Etalon and how do we make them?

Monday, November 23, 2009

Help Needed on Lunt Forum

The New Lunt Solar Forum is live..

We are looking for a few enthusiasatic helpers who are familiar with this type of forum to do moderating and help set up the catagories etc..

Please let us know if you can help out by sending an e-mail to

Working with us on the Lunt Forum will entitle you to discounts on Lunt Products. We can also arrange to send new products to you for test and review.

Thanks in advance...

Sky and Telescope Hot Product 2010!!

We certainly appreciate being recognized by Sky and Telescope for a Hot Product of 2010 Award.

This award has been presented to Lunt Solar for the LS60T/Ha/PT system.

The Pressure Tuned System received an overwhelmingly positive response when shown at NEAF, RTMC, and PATS in 2009. I will be writing a full editorial about the Doppler True tuning system with insights into how to get the most from this system, and why this new technology is such an innovation to the Solar Telescope.

Thanks again to all the folks at Sky and Telescope for picking Lunt Solar and the LS60T/PT. I am very proud of this scope and enjoy testing them every chance I get.

NEAF shirt spotted in Peru!!

I'll have to get Rikki to do a little write up about what it's like living in Peru.

Here is an image of Rikki with Jesus, the guy who drives her too and from "work" every day.

Is that a NEAF shirt that Jesus is wearing??

As some people know, Rikki lives in Peru. She runs the Lunt office from a small office in the town near where she lives. It must be nice to be chauffeured to and from work.

When I get into the office in the morning, I see the mouse cursor on her virtual terminal moving around. She uses an internet based program to chat with Jen in the office all day for free!! You know she's here all day, but you never see her...

I won't say that it hasn't been without it's small glitches, but I have to say that the virtual commuting really works even over thousands of miles to a developing country..

What else does Rikki do in Peru and how did we get this worked out?? I'll have to get her write up a little blog and send in some pics..

Stay tuned..

Tuesday, November 17, 2009

Great Activity Today !!!

Tucson, Arizona has cooled some from last week. One week ago today it was 90 degrees, today we are in the low 70s.. oooh that's chilly...

Along with the cooled temps has come some nice transparent skies. I was testing today and I am very delighted to see several good active areas and as many as 4-5 small developing areas. In addition there are filaments on the surface.. woooHooo!

I hope you get a chance to get outside and view, it's very nice to see the significant increase in activity over the last few months..

Let me know what you see..

Monday, November 16, 2009

Limited Edition LS75F/HR Un-Obstructed

A HR LS75F Un-obstructed filter with matchable BF at <0.6Angstroms (single stack).

During the process of R&D I have been working with new coating technologies that are very low stress and very high finesse. As you know, these coatings will be made available in the new LS152T.

One of our recent projects was the manufacture of some un-obstructed larger 75mm Hydrogen-alpha etalons. My intention was to build one and keep it for myself.

Due to batch costs, it was just as costly to make one as it was to make a few :)

As luck would have it, we have been able to produce a couple of these etalons and I have decided to make maybe 5 available. These filters are not part of our normal production and when they are gone, they are gone, we will not take any orders for more. They are a limited edition signature series filter. There is the possibility of matching 2 for a single DS system.

A little about the etalons:

Internal aperture obstructions are used to maintain the parallelism of the high reflector plates typical to an etalon.
Removing the internal obstructions, or feet, requires that the etalon plates be manufactured to the highest specification for flatness possible. Generally better than 100th wave.
In order to prevent stress to the plates (bending) after the coating process, the coating has to be done in a system that can put down a hard, accurate, dielectric at very low heat. This process is often refered to as ion assisted deposition.

In order to decrease the bandwidth, we had to improve the high reflector dielectric properties. However, in general the trade off has been that plates flat enough to take advantage of the improved coating, were too costly to produce. (higher R needed better flatness).

The coatings that we are currently introducing have higher finesse and lower bandpass. While also providing higher contrast (noise to signal and all that). We are making the blacker, black, and the brighter, bright. Sort of like HD for solar viewing..

I will discuss more about the coatings in a future blog..

The specifications are as follows:

Type: Single Etalon Front Mount Filter
Size: 75mm Un-obstructed
Bandpass: <0.6
FSR: 11 Angstroms
Blocking Filter: Price includes B1200
Adapter Plate: Not Included (POR)
Price: US$3,985.00
Availability: Limited from Stock (check your local dealer or call us)

These are subject to prior sale and we will NOT take orders after they are gone.

Each filter will be signed and dated.

We have a few other fun things coming up, so you will have to check back here to hear about them first. (How about an unobstructed 150????) ;)~

Friday, November 13, 2009

One Thousand Dollar Giveaway :)

In the spirit of awards and the launch of our new website, Lunt Solar will be giving away a total of US$1,000.00 in gift cards to be used toward the purchase of any Lunt product at any authorized Lunt dealer worldwide..

Entries for this event should be received by December 31st 2009. All entries received after that will be included in January 2010. Award winners will be notified in early January.

How do you enter??

Simply submit; a series of images with related text, an editorial article, a "how to" article, educational article, etc.. Keep the submission relevant and original to anything Solar. It doesn't have to be observing related.

All submissions will be reviewed and prizes will be awarded to those that are interesting, fun, creative, and entertaining.

Submissions will be placed into our blog or on our website.

Please include return contact information in all submissions.

Submissions and questions should be sent to:
Please use the sales e-mail until we have finished uploading the completed website and accounts this coming week....

Check back often for more info and updates.

Thursday, November 12, 2009

This is what Solar Minimum looked like ;)

Greg Piepol sent this image of the Sun a few weeks back. I am not sure when it was taken.

Assuming this was just a couple os weeks ago, we can certainly appreciate that the Sun has become a little more active in that timeframe.

Although we still have a long way to go before we see the amazing events that the Sun displays during it's Solar Maximum, I think we can all feel good about the fact that Solar Minimum is over.

Hopefully we won't be receiving any more images like the one attached for a while ;)

I am going to stop the further developement of the Adobe Photoshop Solar Features plugin package. The plugin would have allowed for the "enhancement" of Solar Minimum images.

We have received a few recent images and I will be getting those added to the website soon. There's still alot of work to be done on that site.. Keep the submissions coming, and feel free to comment and ask questions..

Wednesday, November 11, 2009

Popular Science Best of What's New 2009

A quote....

"For 22 years, Popular Science has honored the innovations that surprise and amaze us - those that make a positive impact on our world today and challenge our views of what's possible in the future." said Mark Jannot, Editor-in-Chief of Popular Science.
"The Best of What's New Award is the magazine's top honor, and the the 100 winners - chosen from among thousands of entrants - represent the highest level of achievement in their fields."

We are obviously very pleased to have received the BOWN 2009 award in the Recreational Catagory for the New LS60 Pressure Tuned Telescope. See page 58 of the December issue, or check on line when it goes live.

Although it has long been known that altitude changes move the center bandpass of an air spaced filter, it wasn't until June of this year that the reality of a system that incorporates this technology was brought out into the mainstream. A simple system that simply increases and decreases the air pressure inside a sealed cavity.
This change in air pressure results in a change in refractive index which alters the interference of the light as it enters the cavity. Simplicity! This system basically does the same job as heat would do to a solid design, but instantly, without power, at the turn of a wrist.

Look for some exciting new developements from Lunt Solar in the next 6 months. Along with some R&D projects which I will continue to discuss as I can, we are close to completion on the developement of several new products..

Thanks! to Popular Science for recognizing Lunt Solar as a leader in it's field.

Tuesday, November 10, 2009

First Week of November (Last Part)

As of November 1st we officially began to move into our new expanded facilities next door. Our landlord, Steve, has been nice enough to let us store our cases, shipping containers etc. over there for the last few months until the facilities were ready. The new facilities increased our square footage by about another 40%.

The expansion incudes a few more offices, a nice education/AV area with kitchen and restrooms, and in mid area a nice big fully climate controlled room for our upcoming coating facilities with large double doors to our current assembly area. The back of the area has been heated and cooled, but is currently used as a main storage area. During the buildout of our current area, we had the fore thought to put 800 Amps of 3 phase power in, so the new area has plenty of juice to keep us going.

I'll have to get some pictures up, but it's hard to believe that we first moved in to the current building in February of 2008. The building had a small kitchen, and a lobby. There were NO bathroom facilities. (We made friends with the neighbors very quickly ;). The first 2 Continuous Polishers were working in the kitchen area on very long extension cords. I had an electric heater on one wall and an air conditioner on the other, both fighting to keep the un-insulated room at +/-1 degree.

6 months later we were able to move out of the kitchen and populate the new building just in time for our open house..

14 months later we are still expanding and I am still working very hard to increase our capacity to meet the ever growing demand.

First Week of November (Part 2)

During this week we finally finished our 6th Continuous Polisher.

All the polishers at Lunt are custom designed and fabricated on site. They are currently all 48" diameter with a capacity for about a 12" part. In our application we use plastic fixtures on the lap to hold multiple sizes. We also utilize a large conditioning wheel that runs continiuously on the lap to maintain the required flatness to the parts being polished.

The 48" granite lap is supported on a thick steel plate which mounts via a very heavy duty machine bearing to our custom tables. Our tables are designed and manufactured to be very solid. The lap is driven by a 5HP motor with a large gear reducer, all controlled by a variable speed controller. Due to the fact that our laps generally run 24 hours a day, 7 days a week, we have ensured that all components are over sized for the job.

The granite forms the solid and thermally stable foundation for the polishing pitch. We use a Gugolz fine pitch. We heat the pitch up in a very large pot and once fully liquid, we add secondary components to ensure that the lap will remain firm and stable for long periods of time.
These additions make the lap very "hard". The trade off is that it takes many hours just to push a lap 1/4 wave in each direction. The benefit is that the lap remains flat for extended periods of time, allowing us to finish an entire batch of glass in that timeframe. This also ensures that the laps cannot drift too far while being run overnight. The hardness of the lap and the fine polishing compound assure that our flats are very precise and have no roll off at the edge.

Our next project is the fabrication of a 36" Continuous Grinder. David, our glass grinder, spends 8 hours a day grinding glass from rough cut to fine grind. A second machine will allow us to provide just a little more ground parts than the optics shop currently needs freeing David to hekp in other areas.

In addition to the 6 48" CPs, we are in the middle of construction on our 72" Continuous Polisher. The granite has arrived, and the steel base is finished. This machine will be used to manufacture precision flats up to 24" in diameter. Recent large flats were finished on a large draper style machine. Although we eventually met the specifications of 1/10th wave over 20", we have certainly concluded that a large CP is the way to go.

Monday, November 9, 2009

Outreach in Riverside, CA

I wanted to share my experience with this new gear.

I don't know what Andy does when he matches this scopes and filters up but I am just completely blown away by the views with the new LS60THa scope and my original LS50FHa filter. This set up starts to mimics views I had years back with a buddies older Coronado Solarmax 90 filter on a TV101 scope! I knew double stacking was the way to go but seeing it real time with this latest technology really reinforces it.

I got first sunlight Saturday morning and could see so much detail on a new emerging active region that day. The bright spot with detailed twisting was very easy to see and study. The orange peel was so intense that the sun's globe was starting to show the classic 3D quality of truly high end H-Alpha rigs. And, amazingly, the double stack even at 50mm aperture was still able to show the prominences extremely well even while showing all this surface detail. How can this be!!? Most smaller aperture double stack H-Alpha filters and scopes in the past just showed higher surface detail at the strong expense of easily seen edge detail. Not both at the same time. This little additional gift to the views is just more iceing on the solar cake.

Using the scope and filter set up at the large STEP Conference outreach here in Riverside for the last two days presented easily seen surface detail for every single student and teacher. Every single one. No guessing. There was never any......"well I see it sort of but I'm not sure". Even the younger children could view the orange peel, filaments and active regions clearly. Lots of smiles or "that's so cool!" or "that's really our sun? Are you kidding me?....awwwwesome!!"

I now have the ultimate solar outreach tool that can be use to share our star with many thousands of the public of all ages over the years. I have tools to do serious outreach all day long. Not just at night. For an outreach junkie like me this is true Nirvana.
I thank all of you guys involved at Lunt Solar Systems for bringing this company to market. You folks really are continuing the vision of bringing H-Alpha observing to the masses. All I can say is your service and products speak for themselves.

.....Thanks for these very kind words, we look forward to hearing about ongoing outreach from Riverside and in your area.....

Thanks again,
P. Agins
Riverside Astronomical Society
Outreach program

Saturday, November 7, 2009

The NEW Website!!

The new Lunt Solar Website is almost finished!
........It is almost finished... right?..........

With DNS transfer scheduled for Wednesday, November 11th I am excited about finally starting on a website dedicated to everything Solar. With live streams in Ha and CaK, news and events, forums, galleries, and editorials provided by the users of solar equipment.

We would like to see Solar enthusiasts get involved. Jot down a few stories, ideas or experiences and submit them for the site. We will be featuring articles on past and upcoming events, your local outreach efforts, and a chance to share you knowledge of observing and imaging. And please include pictures!!

The new community area will be dedicated to everything solar it does NOT matter what brand of scope you use. I have been involved in the solar filter business since about 1998, I understand that Lunt is not the only manufacture of Solar equipment, the fact is we all share the same interests and should do what we can to promote the hobby of Solar to everyone. I am certainly proud of the equipment I helped produce before Lunt, and it is a result of that experience that I am able to push it's continued evolution..

So put pen to paper and submit "articles of interest" to

We also need to get the word out about the new website and the blogs (there are 11 of us in this area).

The blog will be attached to the new site once the site is live..

First Week of November (Part 1)

The first week of November has flown by. A week ago today we were getting ready for Holloween night, it'll be Thanksgiving before you know it!!.

Testing, new products, and website were the projects of the week.

The image at left is the New LS152T/PT. This is currently the largest dedicated telescope that we manufacture. This is a working prototype and was on display at PATS. It had been my intention to take it outside on the Sunday, but the mount that I was going to borrow was sold on Saturday. I did try the mount it was displayed on, but that was a drop waiting to happen.

The internal lens sets for the system are almost finished. The prototype lenses were "off the shelf" and weren't quite optimized for the system proviving only about a 70% sweetspot in the center of field. The production lenses have been designed to the optical system. They are also slightly larger than the prototype given more aperture to the beam.

The LS152 contains an unobstructed 60mm HR (high resolution) etalon. This is a new etalon design and provides for high signal to noise ratio which greatly darkens that background allowing for stunning contrast on edge details.

I have already had one person ask about the unobstructed 60mm, and before the questions are raised and the assumptions made in other forums, I will state that we will not be introducing the LS60F until Summer of 2010. Due to the very high demand for the other products, we will not be tooling this particular size at the expense of current production. Our LS60F production is currently limited to the LS152T, and takes the place of the production schedule for the LS200T.

The estimated US$ retail for this instrument is $7,495.00 (this does NOT include the CaK module). For those that have the LS200T on order you will be receiving the LS152T at no additional cost. If you purchased the CaK option for the LS200T you will also be receiving that at no additional cost. As you know, the LS200T was introduced at 5k. It was the intention to increase this price once the system was shipping and had good reviews. As I will explain in another post, the LS200T could never meet both the performance requirements that I had set for it, while also meeting the strict safety requirements. The trade offs were leading to unacceptable compromizes on both sides. Safety will always be of the highest priority to ANY solar product.

For those that choose to accept the exchange, I promise that you will be receiving a solar system that exceeds my expectaions for what the LS200T was going to do. By defualt the delays have allowed for the incorporation of a 60mm etalon instead of a 50mm. The new HR (high resolution) coatings will be incorporated standard, and the value of the package itself will provide a good return on investment should you ever choose to sell.

For those that cannot accept the exchange, we will refund any deposit in full.

Monday, November 2, 2009

Recent Trip to Mt Lemmon Sky Center

This image was recently e-mailed to me from my Landlord. He and a group from his church spent the day and part of the evening at the Mt Lemmon Sky Center.
For those that attended the Open House at Lunt Solar a year ago, you will remember the visit to 9,000 ft. It was about this time of year and although the weather was clear and sunny, the temperatures were very cold.
Shortly after the visit we donated a LS100T/PT to the facility in appreciation of their hosting the event and providing everyone with a look thru some of their large scopes. Everyone had a great time.

We chose the LS100T/PT specifically because of the high altitude. A large aperture scope in great skies without the issues of air pressure to the air spaced etalon.

I hadn't given much thought to the scope on Mt Lemmon until I received this picture. Steve and the group were wandering around the domes, when Steve recognized the name on the 100T. He'd never actually looked thru one of my larger scopes before and expressed his excitment at having the chance to look thru one of our systems "in the wild". He was very pleased with the view. Everyone in the group had a chance to view the active region of last week.

This scope was provided to allow the Center to provide visitors a chance to view the Sun. The Mt Lemmon Sky Center is open to the public, and often receives large groups of children and adults who are interested in learning more about astronomy as well as the nature of the mountain.

For more information on the Sky Center you can visit

The facilities were remodeled about a year ago and I have to say that they did a fantastic job. From large kitchen areas, to private bedrooms, and a first rate meeting/audio visual area.

We are hoping to visit the center at our next Solar event which is now tentatively planned for March 2010.

Friday, October 30, 2009

Pressure vs Doppler Shift (Part 3)

The diagram at left shows the system has been fully pressurized. This pressure is equivalent to about a 12,000ft altitude change.
The air inside the sealed chamber has been compressed due to the reduced volume. As a result the refractive index of the air has increased and caused the CWL of the etalon to move to the blue or high energy side of the Hydrogen wavelength.

Due to the fact that there is no tilt involved, the image field remains flat and very precise.

Traditional tilting allows the Doppler shifting across the field in a plane perpendicular to the axis of light. The user can see a change to the image that allows for the viewing of proms and then filaments. The optimum position is when the proms and surface are both fairly detailed. Overtilting will tighten the bandpass but will also produce a banding effect. The resolution under the band is higher, but at the expense of the entire field of view.

People often feel that the entire field should be as good as the area created under the band. If this were possible, the systems would be spec'd at a much lower bandpass. If a band occurs, the system has probably been over attenuated.

True Doppler Tuning allows for a shift into and away from the user. Adding a 3D component to the viewing experience.
While it has minimal effect on proms due to their being at the edge of the disk, it does have an effect on filaments and active regions.
While looking at a filament at the center of the Sun the user has the ability to Doppler shift from the base of the filament to the tip, following the filament thru it's structure toward you and away from you. Allowing for enhanced visual and imaging capability for the observer as well as a research tool for the avid hobbyist.
The tuning system provides an order of magnitude more precision to the tuning of the desired features.

We are working on designs to the LS100F and the LS100T/Na utilizing the same technology.
The LS100F will be remotely operated for those that have this filter mounted on a long FL scope and do not have 4ft long arms.
We are currently manufacturing the LS60T and the LS100T via this technology.
The LS60T is fully upgradeable to the new Pressure Tune System at any time. However, it does require a return to the factory.

End of Part 3

Pressure vs Doppler Shift (Part 2)

The diagram shown at left indicates that the air pressure inside the sealed chamber has been increased. At this point the CWL of the bandpass is at 656.28nm. At this position we are looking at the Hydrogen-alpha line and the energy associated with that wavelength.

The sealing of the cavity is done via the collimating and refocus lens so that the etalon itself is isolated from differential pressure.
The piston applies from zero to a pressure that is equivalent to taking an etalon from -500ft to +12,000ft above sea level.
This has the added benefit of making the etalon system altitude insensitive.

In addition the etalon can be used from -50 to +200 degrees Celsius due to the fact that the tuning can compensate for the very small changes that heat would have on the "feet" of the etalon.

I have gone into great detail in prior posts regarding the compromises of tilting internal to a telescope. Only very small adjustments to the tilt of an etalon can be done otherwise the etalon system will begin to suffer from the off axis rays of the re-collimated beam.
People have noted that in internal tilt systems the CWL is very sensitive to even small adjustments of the tilt wheel.
By removing the need for tilt we have placed the etalon in the most optimized position possible.
We install a very accurately tuned etalon. This etalon is tuned to the red side of the CWL. Given that it is already tuned to the red, the user has the ability to shift the tune of the CWL to the Hydrogen-alpha line and then Doppler tune to the blue or back thru to the red.

Due to the fact that there is no tilt involved, the image field remains flat and very precise.

End of Part 2

Pressure vs Doppler Shift (Part 1)

Lunt Solar Systems recently introduced the new Pressure Tune system, or Doppler True Tuning system.

The image at left shows the basic outline of this system. The internal etalon is at ambient pressure. The tuning of the etalon is slightly low, putting the Center Wavelength (CWL) at the red wing of the Hydrogen line. This provides a view of less energetic features in the Chromosphere.

How does it work and what does it do?

The system works because the etalons used in the current Lunt designs are air spaced. These air spaced etalons have been typically tuned to the Hydrogen-alpha line via several mechanisms.

The first is the spacing of the air gap between the high reflective surfaces of the ultra flat plates. By changing the spacing, you change the CWL. The distance of this spacing is generally held constant because the refractive index of the medium between the plates (air) is relatively stable at ~1.
The center wavelength can be manipulated from there by slight tilting of the etalon. This changes the angle of the light at the interface of the high reflector/air layer, having the effect of moving the center wavelength toward the blue.

Slight changes in barometric pressure and/or a change in altitude will effect the CWL due to the change in refractive index of the spacer layer.
These changes can be compensated for by additional tilting provided that the etalon is tuned to accomodate those changes.
Taking an etalon that was tuned at 100ft to 10,000ft would certainly not be within that range.

In the past I have manufactured sealed etalon systems for space flight.
These etalon systems were designed to work in a sealed vacuum. As a result they were manufactured as very highly tuned etalons. By placing them under vacuum, the tuning lowered . Tuning was done to ensure that at full vacuum the etalon was on band.
Additional fine tuning from there was done via heat due to the fact that the vacuum could not be adjusted.

Our technology utilizes air pressure and not vacuum.

End of part 1

Thursday, October 29, 2009

Lunt Solar and our new Website

On November 12th Lunt Solar Systems will be taking it's new website live.

I know that most of you are thinking that it is about time. I couldn't agree with you more.

The new launch will coincide with another very exciting announcement. As a result, Lunt Solar and it's products will be recieving some significant media attention. At the moment this other announcement has to be kept under wraps, but I assure you, it will be worth the visit.

The new website will be far more of a monthly magazine with focus on Solar events and activities. We are introducing an interactive community area and are looking forward to having editorials and blogs from customers and solar enthusiasts. We certainly hope that you will check back often and will participate.
Our goal in 2010 will be to introduce and develop an educational and learning source that will provide resources to all ages for everything Solar.

We are just finishing up our Live Solar feed in both Hydrogen-alpha and CaK, and although we anticipate being able to begin the live feed on Monday, November 2nd, we will bide our time and wait for the new site.

In addition to the above, Lunt Solar is going digital. We will be teaching ourselves the imaging process. I will be blogging our successes and failures, and I hope that very soon we can begin to provide a diary of images of the Sun's growing activity toward Solar Maximum. (we may need just a little help along the way).

Soooo, put your thinking caps on and type a few paragraphs for the new blogs. We would be interested in upcoming events, outreach activities, and anything solar related..

We also need you images for our upcoming new gallery. Please submit your images to Include a brief description of what equipment was used and how, where it was taken, and the name of the person to thank. Images of people looking thru and using solar equipment are also welcome.

More to come..

R&D Projects at Lunt Solar Part 1

It's probably doesn't come as any surprise that Lunt Solar Systems LLC is involved in R&D projects outside the field of Solar Filters and Telescopes.
But it is because of our highly technical and specialized skills that we are often asked to develop unique optical elements that fall within our capabilities and my interests.
Some of these R&D programs are confidencial. Some of the ongoing projects are not, and may not only be of interest, but they may encourage readers to suggest other uses for these technologies.

One of our more recent projects has been the developement of a novel solid etalon design.
The intial concept was for the design of an ulta thin, ultra stable, ultra precise, and ultra narrow bandpass micro etalon.

The project's scope of work consisted of manufacturing a solid etalon that was approximately 0.3mm thick (0.012") at the Hydrogen-alpha line.
Multiple matched etalons needed to be produced. The desired size was 4mm x 4mm.
The Hydrogn-alpha emission line was chosen due to our knowledge of manufacturing at that specific wavelength. However, Hydrogen-alpha is not the desired wavelength of the finished product.

The results have been extremely succesful.

At Lunt Solar we produced what can essencially be referred to as a wafer etalon.
The solid etalon was manufactured from a 80mm piece of low expansion UV grade material. (not zero expansion).
The "spacer" layer was polished to 0.3mm thick and send out for testing prior to further work. We needed to show verification of the spacer layer's precision prior to going to the next step.


The Wafer was first tested for surface flatness. Surface flatness was not the concern given that the etalon would be used in transmission.
It was the Transmitted Wavefront that was specified.

As you can imagine the wafer did suffer from some surface error due to being held in a fixture.

The surface flatness was measured at 1/6th of a wave, some of that coming from astigmatism due to the fixture point.
Power was the major contributing factor to this error due to the method of manufacture.

The Transmitted wavefront results were very encouraging.
The interferometer showed a peak to valley error over 75mm (the aperture of the system) of 1/61th wave at 532nm. The RMS being better than 1/250th wave (the limit of the test system).
This test was over 75mm. The system was not capable of realizing a measurement over 4mm aperture, and the engineer was not able to speculate just what that result would be could it even be measured.

These results were followed by some interesting conversations with the test facility who wanted to know how we had tested the wafer ourselves.
For those that have visited Lunt Solar in Tucson, you will know that I test ALL optics for flatness by eye only.

The wafer was sent out for coating via a low temperature, ion assisted process. The wafer was coated on both surfaces with what I now refer to as the new hybrid high reflector.
Some initial tests needed to be done to assure a "tune" at the desired wavelength.
In this case we tuned slightly low of Hydrogen-alpha in order to utilize the standard method of heat to bring the etalon accurately on band.

The end result was a pellicle wafer of about 80mm diameter. Given the highest degree of precision for the entire etalon, we could now be assured of matching etalons of 4mm x 4mm after the wafer had been diced.

The net result as far as specifications go are as follows:

Bandpass: 0.2 Angstroms
Free Spectral Range: 11 Angstroms
Finesse: 27

A few technology applications immediately come to mind given the controllable FSR and the narrow bandpass. I would certainly like to hear your thoughts on possible applications as well.

I am obviously excited about the prospect of getting this system assembled into the back end of a SCT telescope very soon. The wider acceptance angle of this design vs a conventional higher index spacer material will make the modification to existing SCTs in the market fairly simple and compact.
The fact that the etalon itself is thin and has little mass will allow for rapid temperature change and stabilization.
The use of the proven materials will allow for a mass-produceable 0.2 Angstrom bandpass system with a single etalon. I can hear the calls for a double stack system already...

Moving outside my area of expertise and free thinking for a moment...

The product is of a robust solid design and the CWL of the system can be fixed to a specific wavelength or tuneable.
The thickness of the system lends itself well to the bonding to CCDs. Maybe multiple etalons can be bonded to a single CCD to provide a chemical signature detector?
I have thought about it's use in applications such as ionized gas/chemical detection for a while.

Used in these applications the signal to background noise ratio would be of huge advantage, eliminating all background noise and providing >90% T at the desired wavelengths.

We provide 0.5A bandpass looking directly at the Sun. Ambient daylight would be of no issue.

Ancillary light sources such as laser or short wavelengths could be used to further excite the desired compounds?
Are there military applications for ionized gas/chemical detection for munitions, gunfire etc?? The addition of signature trace elements to munitions that can be optically traced?

Other applications may include laser line stabilization, optical fiber multiplexing, etc...

This is just one of our current R&D projects. It is thanks to this project and a few others which I will outline in another blog that we are rapidly improving the performance of our core products. Success and failure though our ongoing research projects are already seeing a positve impact on the contrast and resolution of even our most basic systems..

Upcoming products will focus on enhanced performance and the ability to accessorize systems for use as educational tools.

I encourage your feedback and comments and thank you for reading.

The Sun and "what am I going to see?"

"What am I going to see??"..

Given today's audio visual technologies, special effects, and image enhancement software, it's not surprising that people expect to see everything there is to see the moment they put their eye to the eyepiece for the first time.
Some walk away having seen nothing. Not taking the time to see a Star in action.
Most others are mesmerized by the site. Cannot believe that they are actually looking at a real Star, our Star. The longer they stay, the more they see. The more they see, the harder it is to walk away.

There's no show like it at night. And as I like to say "It's not a sight you will see everyday" I guarantee tomorrow will be just as unique and equally different.

The Sun is the one object in the sky we don't usually look at.

As with any other hobby, it takes time to learn and how to observe. Much like walking into a dark room from outside, at first the eye sees nothing. Does that mean there is nothing to see?
After just a few minutes, features can be made out, and after several more minutes you can clearly make out all the objects in the room and can navigate the room with general ease.

I once set up a scope for a customer who, after 2-3 minutes, declared that the equipment was somehow faulty. All he could see was a red ball, there were none of the features that were shown in the brochure???.
For comparison I asked how long it took him to learn to drive. "Only a few weeks"...
Hmmm, was the car broken because he couldn't drive it in the first 5 minutes?

Solar Observing is much the same as the dark room.
Up until the point that you put your eye to the eyepiece, the Hydrogen-alpha line was only 0.01% of the total light that your eye sees on a daily basis.

However, what a magical 0.01% that can be. Ionized Hydrogen-alpha. By far the most interesting and entertaining emmission line from the Sun.
I'm amazed that the human eye can even resolve this very narrow bandwidth at all.

To answer the questions; "What can I see?"

First and foremost. Everyone's eyes are different. Please do not walk up to a scope and assume it has been focused to your eye. Take the focus knob, defocus the image, and bring it back to focus. The features you are looking at are narrowly contrasted and a sharp clean focus is essential. As features become apparent, refocus the scope. You will be amazed at the view once the focus is sharp.

To focus on the Sun, simply look at the edge. Focus is achieved when the edge of the ball is sharp against a black background.

At first you will see a red ball. Your eye is basically saying, "yep, that's red against black, and that's what I will show you".


During the day your eye's pupil is very small. It is reducing the light into the eye to a comfortable level.
When you put your eye to a telescope your pupil will typical dilate quickly (open) to compensate. The image is basically red against black, and the eye has learnt to show that information quickly.

However, after 10-20 seconds your eye is adjusting to the reduced light. The more light outside the scope you can block, the better the adaptation.
As you look around the edge of the disk, start at 12 o clock and work around, you will come accross what look like flames protruding from the rim. Small flame like structures are Spicules and Prominences. Large flame like structure can be large Prominences, Flares, and even Mass Ejections. Obviously, the larger the structure, the easier it is to see.

As you study these things, your eye will quickly perceive the lighter and darker contrast of the narrow bandwidth. The feature become very aparent and the flame like details are fully visualized. This is generally followed by a "WoW!" from the observer.

If I don't hear the "WoW!" I know they haven't SEEN the Sun yet.

The features you are looking at can last hours and even days. As the Earth rotates around the Sun, the features will appear to move accross the Sun's surface.
This allows the observer to see the details in various angles and positions both off the edge of the Sun, and in cooler contrast to the Sun's bright and hotter surface.

Over the next few years events such as CMTs (Corronal Mass Ejections) and flares will become more frequent. They are by far the most awe inspiring events that can be viewed thru a Solar scope in real time.
Often starting as a large Filament, or Active Region, they quickly develop in energy, resulting in a Mass explosion from the Sun's surface. Many pass harmlessly by, while others can hit the Earth head on. This can disrupt our communications, electricity, and provide awesome light shows as the Earths Atmosphere is effected.

The cause and effect can be seen and felt. The next time you see a flare hit the Earth and you cell phone doesn't work for a while, you'll know why.

Today's Lunt Solar 60T/PT Solar Scopes are ideal for both the casual observer and the avid hobbyist who seeks to study the Sun's day to day changing activity.

People are becoming far more Solar aware. From the effects of global warming, to the distruption of global systems, to the energy that we can now harness.
The Sun can teach many aspects of science from the warmth of a sunny day, to the reaction in plants essential to their growth, to the harnessing of Photons for electricity, to the Sun burn on your skin.

I often do outreach to school kids. Both the kids and the parents get a hands on
lesson with the scope and I generally teach the science basics while they look thru the eyepiece.
Kids adapt quickly and often see activity on the surface right away. They talk about volcanoes, fire, and fuzzy worms crawling on the surface. They are eager to see, and eager to learn.
Set up a scope sometime during the day and invite people to look.

"What can I see?".....

An ever changing and dynamic Star in real time.. Our Star.
The violence of the upcoming Solar Maximum.
The cause and effect of the Sun's activity.
You will learn to see the fine feather like details of the faintest prominence. The bright berth of a Solar Flare, it's rapid growth of energy, and it's departure from the Sun's surface into space.
You will see catapillar/worm like strucures ( Filaments) snaking across the Sun's surface, spirals of gas activity spewing and churning from active regions above Sunspots, and if your lucky, the violent eruption of an X class flare from the surface, an event which is highly energetic, fast evolving, and really does provide that full appreciation of just how close we really are.

The Beginning of a new Solar Maximum

The Sun is our Star, and as you would expect, our Star is hot, bright, dynamic, and sometimes quite violent.

At 93 million miles away, we are ideally placed at a point where the Sun provides just enough warmth and energy essential to our living planet, Earth.
At only 93 million miles, the Sun is close enough for us to view it's surface thru a relatively inexpensive scope from the comfort and relative safety (Sunscreen please) of our backyards on a clear and warm day.

What! Astronomy during the day? Lunt Solar can show you how.

To a growing many, daytime observing is the only time they can see a Star. To teachers it's an ideal way to bring the science of a living Star to school kids, and to parents the exploration of the Sun shared with their own children. No more staying up until 2AM in the pitch black and potential cold to visualy view pinpoints of light.

What's more fun than looking at that fireball at the center of our own Solar System?

For the thousands of people who already own a Solar Telescope you've already had a hands on appreciation of the dynamic nature of the Sun's daily cycles.
Given that the hobby of Solar observing really didn't become mainstream until the late 1990's, relatively few have probably witnessed the ferocity of a Solar Maximum.

For those that began the hobby in the last few years, you may be wondering what all the fuss is about.

The Sun has been at a slightly extended Solar Minimum of about 1-2 years. This is a time of reduced Sunspot and Flare activity. Being a living Star, the Sun's activity "breathes" in and out over a period of about 12 or so years.

The Sun has been holding it's breathe.

For those that are interested, Solar Minimum is now over, and the next Solar Maximum has already begun. Getting a Solar Telescope delivered by Spring maybe just in time.

The Sun has begun to let it's "breathe" out. As it does so over the next few years, the Sun will become far more active. There are already daily signs of increased Solar activity. My daily observations compared to 1 year ago clearly indicate an increase in daily Sunspot count, Prominence activity, the apprearance of Filaments on the surface, Active Regions, and even the rare Mass Ejection.

So how do you see the Sun?

Although the core technology, or the Etalon, of Solar Telescopes has not changed over the last century, the idea of actually looking at the Sun didn't catch on in
the mainstream until the late 1990's. Before that time, Solar observing was left to the "professional" elite who paid out 10s of thousands of dollars for the precision optical systems required.

Over the last 15 years, the price of a Solar Telescopes has dropped to a point where the "amateur" can make the choice between a good nighttime scope, or a great daytime scope. Even today's basic Solar Scopes are by far the most advanced ever made.

With entry level Solar Telescopes at $600, and the well fitted LS60T/PT at $1400, the ability to enter the rapidly growing hobby can be achieved by many, and before we make a comparison to that nighttime scope, lets not forget that the LS60T
contains 17 precision aligned filters and optical elements that provide redundant 100% safety allowing us to view the Hydrogen-alpha emmision line (ionized Hydrogen)
at a bandwidth of less than 0.7 Angstroms (the spectrum is 7,000 Angstroms wide), while reducing all other wavelengths to absolute zero.
That night time scope has 2, maybe 3 lenses/mirrors.

Clubs and events are popping up everywhere. Solar viewing events are being paired with nature viewing events like hiking and birding.
Many cities have yearly science expos where Solar vendors are now showing and discussing the latest equipment, technology, and current solar events.
Solar forums are growing. People are learning to image the sun quickly and easily with simple camera equipment, while others sketch what they see visually.

Education and learning thru hands on observing.

Over the next few months and year, we will be working on promoting the Solar Community thru our new web magazine at Providing education not only on the use of our Solar Telescopes and Equipment, but also the education of the science of the Sun itself and it's effects on our planet.