ISTAR Optical

istar logo 2
istar AT150
ISTAR OPTICAL produce a small range of exciting refractors in achromatic and apochromatic formats - ultra high quality lenses, excellent mechanical construction, at down to earth prices.
The Phoenix 204-6LT is the best value 8inch achromat available.
In addition, Istar uniquely design and produce the Rx technology range of anastigmatic doublets, offering significant improvement in chromatic aberration and reduced image spot size when compared to Fraunhoffer achromats.
This optical arrangement yields near apochromatic performance but with the major benefits of lower lens weight and faster cool down time than triplets - and considerable cost savings.
Istar's H-alpha solar lenses are unique in the market. Large aperture H-a tuned achromat doublets from 150 to 250mm aperture offer the solar enthusiast the opportunity of constructing a dedicated solar telescope of serious capability.
 Istar Phantom 152mm F7.8 Fluorite triplet apochromat 
 Reviewed by Neil English for Astronomy Now magazine - January 2012
" No false colours were visible either in or outside focus, a testament to the superlative colour correction of this optic. Save for a very small but acceptable amount of field curvature with inexpensive wide field eyepieces, I couldn't detect any other aberrations in the Istar Phantom triplet."
( On Jupiter )  "During moments of excellent seeing, stupendous amounts of detail could be discerned on the giant planet using a power of 197x, almost as if they were laser etched onto an off-white oblate disc."
" Low power views of deep sky objects are gorgeous. The Perseus Double Cluster for example, located high in the eastern sky, was jaw-dropping with the Phantom."
" Make no mistake about it; this is one impressive deep sky visual telescope."
" The Istar Phantom triplet is one serious telescope for the money. Serving as both a first rate photographic and visual telescope, it is exceptionally priced in comparison to a number of other models on the market. That, together with a waiting time measured in months rather than years, and you can see why it would appeal to many discriminating observers and imagers."
  Jupiter073011ten                                       lunar1004one
                  Jupiter 30th July 2011                                                                                 The Moon October 4th 2011
                   Images taken  with a Phantom 152mm F7 CaF2 Fluorite Triplet - courtesy Mike Harden, Florida
 Perseus 150mm F12 achromat 
 Reviewed by Steve Richards for Sky at Night magazine - December 2011
" Views through the Istar were bright and full of contrast..."
" Substantially built from aerospace-grade magnesium and aluminium alloys, with many parts machined from solid block, the telescope exudes quality."
" The Istar Perseus would make an excellent upgrade for lunar, planetary and double star observations, and it's high-contrast views would also come in useful when looking at many deep-sky objects, such as planetary nebulae and globular clusters."
Tube Assemblies - all prices subject to confirmation at time of order due to currency fluctuations.
Availability - Istar have anounced that production of all OTAs will be phased out this year, with only lenses being readily available.
We are able to quote for a bespoke OTA for special order.
All ISTAR OTAs use aircraft grade magnesium alloy tubing, providing strong and very rigid support. The fully baffled tubes are powder coated for durability, and come with a lens cap. Dewshields now are retractable, some with a bayonet locking system.
The fully adjustable push-pull lens cells and other tube fittings are CNC machined from titanium magnesium alloy, with either a polished natural finish or anodised with colour dependant on product type.
ares wfx 150-5 r35_03
Moonlite dual speed rack and pinion 2" focuser on all OTAs as standard. 
However, a choice of focusers is offered - Moonlite, Starlight Feather Touch, or Baader SteelTrack, all in 2inch fitting.
Finder units are optional extras, and we would recommend the Teleskop Services, APM range or brand of your choice. 

Anastigmatic lens options - Rx technology

This optical arrangement yields near ED performance but with the major benefits of lower lens weight and faster cool down time than triplets - and considerable cost savings.         


Anastigmatic Asteria Range 

Currently  available:

WFX 150-5 R50    Prices from £2895

Sub-compact design in white powder coat finish with detail colour, rings, Moonlite 2.5 inch focuser, 9kilos

AXT 150-8 R35    Prices from £3025

Specification as for WFX, weight 11 kilos

Achromats - Phoenix Range

WXT 204-6 LT £4665

2 element achromatic wide field, same specification as WFX, weight 14 kilos

See the review by Neil English in December 2014 Sky at Night magazine of the WXT 204-6 LT
Specification :  204mm achromat, f5.9, 1220mm focal length.  Fully baffled OTA with retractable dewshield weighs 12 kilos.
Supplied with CNC tube rings and William Optics dual speed rack and pinion focuser as standard - any focuser may be specified at additional cost.
" ..the rich field obsever's dream ticket..."  " ...I trained the instrument on delta Cygni and was impressed to have glimpsed the companion."
" ... I was deeply impressed to fit the entire Pleiades cluster into the field of view!"   Neil's review is very complementary on all counts.



Lens Prices - subject to confirmation at time of order due to currency fluctuations

Availability - please note that all lenses listed are not routinely in stock, small batches being made on a demand basis. This means that lead/delivery times will vary and you should contact us for confirmation. Subject to order status, we may require a 50% deposit.

All ISTAR achromatic doublets and apochromatic doublets and triplets are available for clients wishing to upgrade their existing refractor or build a new instrument.  Lenses are mounted in a CNC machined cell and fully adjustable push-pull counter cells are available at extra cost.


Achromats:  Hand figured doublets in push-pull cell. Broadband multilayer film (yellow). Average Strehl ratio above 0.9 (>F7)

For commercial reasons, only 150mm plus aperture lenses in the following focal ratios will be offered. 

Smaller apertures and alternative focal ratios may be available to special order, please enquire.




    Prices from 
 127mm  F8 575
150mm F5 , F8, F10  775
204mm  F5.9, F8.8  2150
220mm  F15  PV6  3295
220mm  F15  PV4  2700
228mm F7.7 3015

lens 150 F12

150/F12 Achromat in cell 

Anastigmats: R30/R35 designs provide reduction in chromatic aberration and image spot size,eg R30 gives 30% reduction and performs in a similar way to an achromat of 30% longer focal length.


127mm F12          R30                     875

150mm F5        R50               1125

180mm F8        R35               2074         

204mm F8        R35         currently unavailable

250mm F11      R30               5850

250mm F20      R30               6660


H-alpha solar doublets: Istar are the only manufacturers of Hydrogaen-alpha 'tuned' doublets.

These provide finer detailed solar images and are favoured by dedicated solar observers.

However, they also perform admirably on night sky objects so you don't particularly need more than one telescope.

Images on the main Istar US website illustrate this point -


150mm F10    Ha         currently unavailable

228mm F9      Ha             4925

250mm F10    Ha            10510


Please note that prices on Istar Optical website are ex-works and do not include shipping, import duty or VAT.

Our prices include 20% VAT.