iStar Optical

iStar Optical

iStar Optical

More than a Telescope Manufacturer

More than a Telescope Manufacturer

iStar Optical is known for the design and manufacturing of quality telescopes and lenses for individuals and the astronomy industry. No less than a half dozen professional telescope builders and manufacturers in Europe and the US now implement our lenses in their telescopes. We have produced a number of objective lenses for Universities and observatories around the world including Mount Stromlo observatory   in   Canberra   Australia,  INAF-Osservatorio

Astronomico di Brera in Italy, Swarthmore College in the USA, Hohenkarpfen Observatory in Germany, Pic du Midi  observatory in France and Université Libre de Bruxelles in Belgium.

What you may not know is iStar Optical also designs and produces lenses for “Opto Mechanical” and “Opto Electronics” applications. Lenses and optical assemblies were recently produced for the physics departments of MIT

in Massachusetts USA and Caltech in Pasadena California USA. Specially designed lenses for Holographic applications were delivered to L-3 Communications EOTech in Ann Harbor Michigan USA. Recently iStar Optical became a registered supplier of optics for the prestigious STAR Labs of Lockheed Martin Aerospace and Defense Company.

Call or email today to find out how iStar Optical and their staff of engineers and opticians can provide solutions to your optical needs.


WXT 204-6 LT

This telescope is a great performer in its class, and is a joy to use! It is awesome for observing deep-sky and fantastic for the Moon! CA? Yes, the CA is undeniably present on bright objects, but I think it is up to a person how much it is tolerated or not? For example, I could not take off my eyes off the Moon for an hour or so, even when CA was present, because I was immersed so much in observing the craters and other fine surface details! Is this telescope good? Yes, darn good :-) Actually, this refractor may be the perfect outreach kind of scope!

I am very happy with it!


The focuser is an AP 2.7" with greased rack and   pinion  and  I  added  an  AP  extension

between the focuser and the tube so that it can be exchanged later on for a 4" AP focuser if needed. The length of the system is exactly as planned. I have 7" from the end of focuser to the focal point and it comes into focus with a diagonal even for me who wears strong glasses. The 7" back focus also makes the telescope bino friendly, however, this will need to be verified. The tube mounting is a 15" AP ribbed plate with Parallax rings. The tube is not heavy considering its size. My AP 900 is good enough to hold the refractor, but I have to balance it carefully.



Whitehorse Canada


Viktor Zsohar Proudly Presents the iStar 228mm F/7.7 ATM Build

Strongly Reduced Chromatic Aberration doublet  with a near SEMI APO performance.

iStar is proud to introduce an all new, second generation Ares WFX 150mm F5

with exciting features our customers were asking for.


  The Heart of this wide field Comet Hunter is a recently designed 154mm F5 R50-Slim improved Achromatic doublet.

This new lens is substantially lighter and Chromatic aberration is reduced to near Semi APO levels with unmatched

resolution. New white tubes with all inner parts completely re-designed for reduced weight. Split construction counter cell

with fully retractable dew shield, bayonet style locking mechanism and slim lens cap held by neodymium magnets. Each OTA is

shipped with 360° fully rotatable dual speed 2.0” WO Rack and Pinion focuser in white finish and a set of 160mm “Fast Lock” Mounting

Rings. All scope parts are precision CNC machined in the European Union out of aircraft grade alloys and powder coated. All this for only $2085.



  Watch for the release of our next generation line of super lightweight 8" Refractors the Phoenix WXT 204mm F6, Perseus AXT 204mm F9 and Asteria AXT 204mm F8 R45-S.

Stay tuned!

Over the last several years, iStar Optical has established itself as a market leader in providing high quality achromatic and semi- apochromatic refractors at fair prices. Over this length of time, I have watched the company grow and innovate in new and exciting ways, providing customers with objectives for ATM builds or complete telescopes in traditional or truss tube formats. Recently, the company has been introducing exotic glass types into their designs, thus providing large aperture with improved colour correction to sate a growing demand from the amateur community.


Having fully test driven several iStar refractors, I eventually settled on acquiring one of my own; a beautiful 127mm f/12 R30 Asteria (aka ‘Tiberius’) which has given me immense pleasure in the pursuit of my hobby. Earlier this year, iStar owner, Ales Krivanek, contacted me inquiring about whether I would be interested in test driving yet another product from their first generation stock; a 6 inch (150mm) f/8 achromat. Naturally, I obliged and the following is a summary of how I got on with it.


Fit ‘n’ Finish

The optical tube assembly arrived in perfect condition having travelled across Europe to Scotland from its source in the Czech Republic. The instrument – a first generation iStar model – was very carefully packed and a quick examination of it confirmed that all was well. Just a few moments of casual inspection of the telescope will convince you that the workmanship that went into fashioning the tube assembly is light years ahead of the more ubiquitous Synta designed CR6.


While many have complained that the original, first-generation iStar tubes were over-built and too heavy, I have come to like them an awful lot. For me, they are reassuringly sturdy and reminiscent of the days when quality achromatic refractors were being built by the world’s famous optical houses. They feel old fashioned and look old fashioned.


Like all iStar objectives I’ve had the pleasure of using, the one that accompanied this tube was perfectly assembled within its high quality, adjustable aluminium cell. The crown and flint components are properly spaced, fully-multicoated and are surrounded by a massive dew shield that protects the lens and all but guarantees hours of hassle free observing without the need for a dew band.


J.P. Brahic - French amateur astronomer

Last night I had an opportunity to take my first peek at my friend James new iStar Phoenix 204 F/6. Here in Sacramento, some of the weather forecasts were showing a chance of rain but our best source was saying no rain till the following afternoon. Because of this, we decided it would be smart to just set up on his driveway, just in case the weather turned south on us. When I went to his place, his scope was already set up.

He was on his driveway with 3 streetlights all in sight, and a near full moon just rising. We didn't care, we are passionate astronomers and having an opportunity to just set up and look at this beast on his G11 would have been good enough even if it remained cloudy.

Fortunately, the skies cleared up and the clouds had moved away. Despite our horrible lighting conditions, we were ready to have a first light at this beautiful masterpiece.

First off, I'd like to say the 204/F6 was a perfect marriage for the G11 with an optional one foot extension pier installed. For the first time ever, the big mount looked completely matched with a big refractor mounted on it. When  I  got  there,  the  scope  was  not  balanced  on the mount properly. I removed  one of  the counterweights and ended up with two 21 pound counter weights on the G11.

I slid the scope back in its massive stock tube rings because

because it seemed somewhat front heavy, even with a 2" diagonal and a 41 Panoptic installed. So 41 pounds of counterweights on the G11 was the perfect weight for the big optical tube.

I noticed the Moonlight focuser was adjusted a little too light for his two inch eyepieces, so using an allen wrench, I tightened both screws under the focuser which stiffened up the focuser slightly, and the focuser then felt excellent. When the scope was pointing straight up, the big Panoptic moved like glass in and out of the draw tube. The rotating focuser was extremely fluid, very smooth and precise, exactly what you would have wanted.

With the 12" Losmandy Extension Pier on the mount, the mount was at a perfect height with the tripod legs full extended. Even when pointing straight up, it was at a perfect height for sitting for observing or just leaning forward, and when observing above the roof lines, we were able to stand comfortably. Had we been in open flat horizons, we may have needed one small step on a two step ladder I always take with me. Overall, this scope was matched perfectly to the G11.

With our mediocre skies, I was able to see Cassiopeia and moved the scope over to the double cluster in Perseus.

Even  with  the  near  full moon about 30 degrees from our

target, the big red giants in the double cluster were very prominent and the entire star field was picture perfect pin points. With a big smile, I told my friend Jim that the optics on this scope was excellent. Every star with the widest eyepiece possible was absolutely a perfect pinpoint. It couldn't have been a better image. I panned around and found the ET Cluster, NGC 457. Even with the wide field 41 Pan, the large red and blue star forming the eyes of the ET cluster focuses perfectly. I put in a 14mm ES 100deg eyepiece (85x) and the cluster just jumped into view. Again, perfect pin point stars across the entire field of view, just absolutely perfect optics. This scope had been up for maybe 45 minutes before I started using it, so even in that short amount of cool downt time, there were no issues of waiting for the glass to equalize or settle down. The outside temperature was about 55 degrees and despite the clouds just clearing away maybe 2 hrs earlier, there were no signs of puffy stars.



Phoenix WFT 204-6 FIRST LIGHT REPORT by Ralph Aquirre, California, USA (August 2014)


ATM Build by Jack, September 2014

It’s been obvious for several years that my TV85 and cheap 6 inch Dob in our Florida home consistently outperform (on the usual lineup of urban targets) my TV102 and 10 inch Dob - Newt with a premium mirror in our upstate NY home. Atmospheric and local seeing is very good most winter nights on the east central coast of FL, and poor (on those few nights when stars are visible) in NY. So I transported...


ASTERIA AT 127-12 R30




"The universe is full of magical things

patiently waiting for our wits to grow sharper."

iStar Optical

Eden Phillpotts