Thinking About a New Scope? Think Big!
Latest News & Updates
Fused silica has a beautiful white tint (compared with Pyrex in photo) and with virtually no coefficient of expansion, much lower than Pyrex and Supremax
All 15” and 18” Obsessions use fused quartz (also called fused silica) for the primary mirror glass. Fused quartz is glass consisting of silica in non-crystalline form. It differs from traditional glasses in containing no other ingredients, which are typically added to glass to lower the melt temperature. The optical and thermal properties of fused quartz are superior to those of other types of glass due to its purity. Its low coefficient of thermal expansion makes it one of the finest materials for precision mirror substrates. Fused quart is standard on all our 15” and 18” scopes, both Ultra Compact and Classic models.
30 year anniversary
In 1987 I introduced the Classic Obsession 20” at Astrofest. Since then it has been the most imitated large aperture telescope in the world. I am still am obsessed with deep sky astronomy and producing the finest instruments possible. I’ve built over 2,500 Obsession telescopes, wrote the number one selling book on building big Dobs, started the Ultra Compact line of scopes in 2008, and provided nearly all the design innovations that everyone else imitates. Choose from the warm and beauty of the Classic Obsession or the modern Ultra Compact telescope. Either choice is the best instrument available anywhere at any price. An Obsession Telescope will provide you with a lifetime of observing fun.
Taft Observatory with Obsession 25 inch in Islamic Azad University, Taft Branch, Taft, Yazd, Iran
18 Classic arriving for Ron Lewis in Brandon VT.
Kelly McGrew, 18" UC owner in Land O Lakes, Florida - February 12, 2016
Everyone who buys one of your scopes no doubt tells you how amazing these scopes are—and I’m no exception. Big, fast, and it glides. A friend who was here from Korea overnight will probably be selling one of his motorcycles when he rotates home in order to finance one of your scopes. He has an 8" Dob but after looking at M42 under our stable Florida winter skies for 30 minutes through the Obsession using a Tele Vue 21 mm Ethos and a 13mm Ethos he's got his eye on at least a 12.5-incher. Amazing views!
Ultra res 32K encoders standard with all Argo Navis and ServoCAT orders.
Already have an Obsession scope? Swap out your old 8K or 10K encoders with ultra res 32000 count encoders. More than three times the resolution for improved targeting and tracking.
Don Himes in Chagrin Falls, Ohio - April 30, 2015
A remarkable experience here; by luck rising just before dawn to catch summer favorites with my brother;
- M13 Breathtaking with the 13mm Ethos star deep into the core, huge and bright... truth in advertising for once!!
- M57 Luminous smoke ring bright
- Alberio Vivid, vibrant electric sapphire and topaz like Beta Andromedae...
That evening, against expectations rolled out again for the moon and Jupiter... to my astonishment laid out before me the full aperture resolving power of a 20" telescope working at the theoretical limit. After laser collimation in less than a minute...
Jupiter watching GRS turn into view with a white oval nearby, festoons and much more. Amazed to actually have the impression of Ganymede as a 'ball' rather than a disc and dusky color as opposed to nearby icy Europa.
But at last on the good old moon astonishment is no longer adequate and I was forced to resort to mind-blending for here a beheld a new world as if seen from halfway... I am veteran lunar observer with many instrument and hi def video and have never in 30 years seen the moon like this.
My favorite Apollo 15 landing site Hadley Rille was plainly visible, in the bright, clear and clean image with only the slightest fluttering.
I dared hope, and yes the fabled rille down the length of Lunar Alpine Valley was clearly visible.
The great tragedy of the evening was I only had 360x available; I believe the scope would have supported 500x or more.
Recently picked up planetary nebula NGC 3242 and nickname should be Blue Eyeball nebula... the deep blue color at low power knocked me back, and even at highest power bright and can clearly see the outrageous eyeball 'CBS logo' within... insane!!!
Against all theory and urgent advertising, the big refractor guys will not be hearing from me.
Obsession 20" is four times the telescope for half the money!!!
Dave, I have made major purchases in the past and few so quickly and decisively returned the investment. I once had a Questar...
This is the breakthrough, revolutionary telescope I have needed and deserved all these years.
Obsession 25" on cover of school textbook
That's Tom Miller, Obsession owner at the 25" eyepiece.
Boyd L., 18" UC owner in Sisters, Oregon - July 28, 2014
I live under the darkest sky in North America, but I've never had the breath-taking views now at my eyepiece as I have with the 18" UC! The Veil Nebula presents more detail than I could have ever dreamed. Other astronomers take a look and one-after-another just say "Wow!" "Fantastic!" Add the O III filter and it's just picture-perfect stunning in all its character. You are spot on: The 31 Nagler and the new 13 Ethos make an outstanding duo. I could name all the destinations of my intergalactic travels so far, from the Whirlpool to the Ring to M 13 and the adventure is just beginning with each of them! There's so much more to see and I can wait for more! The lines at the star parties in the Oregon high desert outback testify to the fact that with this 18 UC you have thought of everything. Collimation with the laser takes 2 minutes, and even with bumpy country roads, everything holds extremely well from start party to star party. My Ford Escape is perfect for transporting everything I need to bring along, with room to spare. Combine the portability with the excellence of this fine instrument and I could not be happier. Thank you, Dave, for your nurture from my transition from my former Dob life to this over-the-top UC 18!
Paul W., 25" owner at OzSky Star Party - April 2014
An exceptional view of the Homonculus Nebula surrounding Eta Carinae. I've noted in the past that this object is the only one that resembles its Hubble Telescope image. It more than resembled its Hubble view this week. It was at least as detailed, if not more, in the eyepiece of the 25" Obsession. I've seen this object on my three previous visits to OzSky, but never before like this.
Paul Koller views Quasar PG1634+706 - almost 9 Billion Light Years away
Last October 31st to Nov. 1st 2013 my friend Justin Kabaus (22" UC) and I had a very successful night, observing on the location of Hohe Dirn (Elevation app. 3,000 ft), Austria.
I found my most distant object ever seen -> the Quasar PG1634+706 in Draco -> almost 9 Billion Light Years away !!
Send you a map of this Quasar and a picture from our observation site from the morning after a cold, but beautiful clear night.
Still by far not satisfied to do much more observing with the UC22“ – just would like to have better weather to have more clear nights.
Greetings from Austria,
Paul Koller (;-)) 22UC
Astronomy Sketch of the Day
Rick Angell - Orion's Wreath
I have been having a ball using my Classic 18 to sketch. My Classic 18" is what got me started sketching in the first place. When I got my scope I was able, for the first time, to see detail in objects I had seen many times. But, the thrill was usually: "Wow, I actually found it." The faint fuzzies were just that, faint fuzzies. The thrill of actually seeing detail had me so excited I was running all over the sky, as rapidly as a 6 year-old to a Christmas tree. I could see so much good stuff. But, I soon learned that I wasn't really "seeing" it. I decided to sketch as a discipline to slow me down. I didn't figure I'd really be able to do a good sketch. I had trouble drawing stick figures that would identify the Mens' Room.
I've discovered a few things. First, the Classic 18" seems to have been made for sketching. Second, I can in fact render a sketch that is a somewhat reasonable approximation of what the object actually looks like. I can finally show people what I see in the eyepiece and they begin to understand what thrills me so.
So, this is a long-winded thank you.
Rick Angell Golden Colorado
Check out ASOD today.
18" Classic is now f/4.2
Both the 18" Classic and 18" UC are now f/4.2.
Another dozen brass name plates polished
You could have your name on one!
John Nymark from Edina Minnesota with his 22" UC loaded in his 2012 Corvette.
I have to tell you Dave that your scope is a work of art. I put it together a day or so after I got home. Amy and our daughters were quite amazed at the transformation from mirror box one minute to completed scope the next. Truly elegant engineering, form and function. They also couldn’t get over that we fit the 22" into the Corvette Z06. ~ John Nymark
Measuring the orbits of double stars
Tim C., 25" owner in Statesboro, Georgia - March 19, 2013
I wanted you to know that my 13 year old daughter, Maria, just took the top award in her school's science fair competition, measuring the orbits of a handful of double stars with my new 25-inch. She had a blast. The judges loved it. And Dad couldn't be happier...
We still have Pyrex
In 2008 Corning closed their Pyrex glass factory. Corning decided to get out of the borosilicate (Pyrex) glass business to focus on glass fiber cable and glass for cell phones. Before they closed, we purchased over a 1000 Pyrex optical blanks at tremendous savings. It's the reason we’ve been able to keep prices so low and we've been passing the savings on to our customers ever since. After the Pyrex is gone prices will rise considerably.
Jupiter grazing - Jan. 21, 2013
Claudio Elicer, 15" UC owner in Santiago, Chile
Hi Dave, glad to speak with you again. Just to show you the last Moon / Jupiter meeting, 01.22.2013, with my excellent 15" UC, I have been learning about astrophotography, but I'm still a beginner.
Keep in touch.
Jupiter grazing occultation - Nov. 2, 2012
Talking about having fun – the 18 inch Obsession + Canon DSLR (7D and 5D) – no stacking etc. – just straight forward prime focus (bottom part of a barlow lens - attached to camera adaptor/ nose piece).
We were fortunate to see a grazing occultation and the photon shields (clouds) stayed away JUST long enough!!
Pretoria, South Africa
Retired from dentistry
Not many know that I was a dentist for 33 years. I sold my practice and retired on April 1st to focus more on my true love, astronomy and Obsession Telescopes. I only wish I had done it earlier!
Don't miss Comet ISON. The brightest comet in 400 years will visit earth this October/November (2013). Some anticipate ISON will be as bright as the full moon! Observe the head of ISON with a large aperture Obsession Telescope. It will be dazzling. Don't wait until a month before the event to get your scope as I'll be buried in orders at that time.
OEM discount pricing
on all Televue eyepieces
Obsession is also a Televue dealer. Get Original Equipment Manufactures discount pricing on all Televue eyepieces, coma correctors, filters, and barlows. The new Ethos eyepieces are awesome. Send us email for price list.
26 year anniversary
In 1987 I introduced the Classic Obsession 20” at Astrofest. Since then it has been the most imitated large aperture telescope in the world. I am still am obsessed with deep sky astronomy and producing the finest instruments possible. I’ve built over 2,000 Obsession telescopes, wrote the number one selling book on building big Dobs, started the Ultra Compact line of scopes in 2008, and provided nearly all the design innovations that everyone else imitates. Choose from the warm and beauty of the Classic Obsession or the modern Ultra Compact telescope. Either choice is the best instrument available anywhere at any price. An Obsession Telescope will provide you with a lifetime of observing fun.
New phone number
Phone is now 920-220-1195
Wheelbarrow handles included on all models
Wheelbarrow handles are now standard on all Classic and Ultra Compact scopes from 12.5 to 25 inches.
Jupiter & Saturn images
Taken by Refet Dehari with 15" Classic.
Award winning Obsession 15” f/4.2 UC and 18” f/4.2 UC (Ultra Compact)
See video on our web site or last 15 minutes of the DVD
Introducing entirely new products. The Ultra Compact telescopes are for people that want large aperture that will fit in any car. Completely new design and extremely compact - but same optical, build quality, and ease of use as the Classic Obsession. Awarded 2008 Hot Product by Sky & Telescope magazine, Cloudy Nights Gear of the year 2008 award, Astronomy magazine 2008 Top Ten award, Cloudy Night Reviews Readers Choice – 2007 Top Products award. For info, photos and a streaming video of the 15” UC and 18" UC please see our web site. Both the 15 and 18 inch Ultra Compact Obsessions include premium Feathertouch focuser, Telrad, and counter weight kit. Cost is the same as Classic 15 and 18 inch models with same items. Argo Navis Digital Telescope Computer and ServoCAT GoTo drive options available on both. And if you prefer the warmth and beauty of a fine wood instrument we still offer the famous Classic Obsession series of telescopes.
22 f/4.2 Ultra Compact
We are constantly being asked to make a larger Ultra Compact scope. So we introduced the 22 f/4.2 UC in January 2010. Same award winning design but with 8 truss poles instead of six. Same premium Ostahowski and OMI optics. All optics are tested and figured with wave fringe analysis interferometry, the Gold Standard in the business.
Ultra Compact is even easier to transport
I modified the UCs so they are even easier to lift and transport. The primary mirror can be removed from the VMB (virtual mirror box). At your dark site, take the mirror out of the VMB, set the VMB in the rocker, and set the mirror back in. This means the heaviest item for the 15UC is only 26 pounds, and for the 18UC it’s only 38 pounds. And you still get the wheelbarrow handles if you want to roll the whole scope around.
Premium optics and Ion Deposition enhanced coatings
Obsessions are built with diffraction limited optics from Ostahowski and OMI (Optical Mechanics Inc). All on 2 inch glass. No cheap astigmatic bendy thin mirrors like others use. No fragile plate glass sandwich mirrors. No cutting corners.
These optics have the finest specs on the market, are certified with laser interferometry and have ID (Ion Deposition) 96% enhanced coating. Enhanced Ion deposition is the smoothest, most durable, most opaque (no pin holes) and most reflective coating possible. Now you can have the best optics, the best coatings and the best delivery. Call or email for price & delivery. Secondary mirrors are 1/10 wave or better with interferometry certification and coated with 98% Brilliant-Diamond enhanced aluminum. These are the finest flats and coatings offered anywhere.
ServoCAT GoTo drive
Select the ServoCAT GoTo drive option for your scope and you get the best drive system in the business, including the Argo Navis Digital Setting Circles, high res 10K encoders, powered ground board (prevents cord wrap up), and professional installation.
New Super 10K res encoders
Now when you choose the Argo Navis Digital Setting Circles or ServoCAT GoTo drive for your scope you get 10000 count encoders. Standard on all Obsessions, these super res encoders increase targeting accuracy. No other scope has these.
GOTO TRACKING DRIVE - ARGO NAVIS DIGITAL SETTING CIRCLES
Available now. We can install the new Generation 3 ServoCAT GoTo tracking drive on your new Obsession. Combined with the powerful Argo Navis digital setting circles and 10K super res encoders, this system makes your large aperture telescope a fantastic observational instrument. Seamless operation. Precise tracking and GoTo capability at the push of a button to over 29000 objects. Features so advanced we can't describe them all on this page. Whether you get the ServoCAT GoTo tracking system or if you just want the advanced features of the Argo Navis digital setting circles you'll get factory installation. For more info please see enclosed product sheets.