iStar Optical

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, L3Harris Technologies, 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 can provide solutions to your optical needs.


iStar Optical has been successfully manufacturing 127-250mm F5-F15 achromatic lenses for many years. These lenses are also purchased by various professional manufacturers of achromatic telescopes, as well as by amateurs who build refractors for themselves.


Technologically advanced achromats with the designations R30-T, R35-S, and R50-S (Anastigmatic, T-thick, S-slim) are also very well known because the optical design reduces chromatic aberration by 30-50% when compared to Fraunhofer’s conventional achromat designs. This is due to an improved false color correction due to incorporation of a dense flint (type of an ED glass) in the design.


Read more >


by Josef Ladra, September 24, 2021


See stunning photos taken with iStar Optical instruments

Newly Designed & Precision Manufactured

Line of Super APO Triplet OTA  Refractors


iStar’s newly designed and produced Phantom FCL 140-6.5

is the first-ever imaging Super APO refractor with fully

detachable 80mm rear section to allow for the use

of binoviewers, and imaging equipment requiring

extended back focus distance.

iStar Phantom FCL 140-6.5 Super APO Triplet

for Full Frame (FF) imaging use William Optics Flattener 68III

for APS-C imaging use Starizona Apex ED L 0.65x Reducer/Flattener



(140mm F/6.5 Lens in Cell and Apex ED-L corrector)

$ 2,325

$ 2,209

ATM built - iStar Optical 140mm f6.5 Super APO Triplet

Robin Lim

Hi all


Just want to share with you all my experience on building my own APO Triplet refractor. I always wanted to build my own refractor, I did it recently by purchasing a skywatcher esprit 80ED lens and build the tube around it, but then I wanted a bigger scope with longer focal length.

My aim is to build myself a refractor with APO Triplet lens. It is hard to get the manufacturer that sell the lens cells alone so when iStar Optical released their first batch of 140mm APO Triplet lens, I did not put any hesitation and take a bold jump to be the first adapter of this lens.

It took me 2 months to get the lens from ordering to delivery and meanwhile, I communicated with iStar optical to get the detailed lens drawing as well as the focal length data I need to determine the tube size.

Read more >


New iStar 140 F/6.5 Super APO triplet

Build by Robin Lim, Singapore

Photo of NGC3372 (Eta Carinae Nebula) taken by Robin Lim using


Lens:  iStar 140mm f6.5 Triplet Super APO

Camera:  QHY600M

Field Flattener:  William Optics Flat68III 1.0x

Mount:  Skywatcher HEQ5 - Belt Modded

Guide Scope: William Optics Uniguide 50mm

Guide Cam:  QHY5III290C

Capture Software:  Astro Photography Tools

Guiding Software:  PHD2

Focuser:  Pegasus Astro FocusCube2

USB Hub:  Pegasus Astro USB Control Hub

Flat panel:  Pegasus Astro FlatMaster 150

Filter Wheel:  ZWO 2" EFW

Filters:  Chroma 3nm narrowband filters, 50mm unmounted

Image Stacking:  AstroPixelProcessor

Post Processing:  Adobe Photoshop, HLVG, Topaz DeNoise

iStar 140 F/6.5 APO triplet


Frames taken

Ha:  8 x 600s

Sii:  6 x 600s

Oiii:  6 x 600s

Total integration time:  3 hours 20 minutes


Calibrated with

10 x Dark Frames

100 x Bias Frames

10 x Flat Frames for each filter


Taken from Singapore, Bortle 9 sky, 07 February 2021



Eden Phillpotts

patiently waiting for our wits to grow sharper."

"The universe is full of magical things


Each international customer is responsible for paying local taxes and fees! We ship from Tucson, Arizona, USA so only US customers (excluding Arizona residents) will receive their items tax free. Contact your local customs authorities before ordering.