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ASKAR FMA F135 f/4.5

ASKAR FMA F135 f/4.5


Regular price £315.00
Regular price Sale price £315.00
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ASKAR FMA F135 f/4.5 Astrograph Telephoto Camera Lens - Triplet/Sextuplet APO Refractor Telescope / Guidescope / Finderscope.

The ASKAR FMA135 objective lens features a triplet air-spaced APO design at the front plus a three element flattener at the back that allows superb flatfield photography with cameras with a sensor size up to APS-C size. The front triplet part includes an ED (extra-low dispersion) glass, providing excellent correction of chromatic aberration, which lays the foundation for high quality astrophotography and observation. 

The FMA135 comes with an adapter that makes it possible to use a 1.25" standard astronomy filter to be used at the front end of the astrograph and the standard configuration also includes a tube ring with a finder base. The tube ring slides onto the field flattener part of the setup as seen on the below image.

At the back end of it there is a standard M42×0.75 male thread (T2-thread or T-thread), so that you can connect most DSLRs, compact system cameras or specialist astronomy cameras.

DSLRs would usually require a camera specific T-ring. Many astro photo cameras would come with the necessary adapters, but we'd recommend to either contact the camera manufacturer or contact us if you are not sure if you have all the required adapters. 

The FMA135 also comes with a 1.25" visual back for the attachment of an eyepiece or a guiding camera. A high-quality helical focuser helps to achieve focus and there is a small thumbscrew to lock it in position once focus is achieved. This latter feature is mainly used for astrophotography, but also useful if you use it as a guidescope. 

We hope that the ingenious optical design of the FMA135 will offer you a superb imaging and visual experience.



  • Aperture: 30mm
  • Focal Length: 135mm (with or without flattener, i.e. the flattener is a non-magnifying flattener)
  • Focal Ratio: f/4.5 (with or without the flattener, as above)
  • Objective type: Air-spaced APO triplet (including ED glass element or Sextuplet refractor for astrophotography up to APS-C sensor size)
  • Overall length: 113mm (photographic mode with flattener)
  • Weight: 280g
  • Rear-end adapter type:  M42x0.75mm thread (for imaging) or 1.25" visual back (for visual observations)
  • Package content: FMA135 (one set). tube ring (one piece), 1.25" visual back (one piece), screws (3 + 2 pieces), instruction manual (one piece)


    First test results from Zoltan (director of 365Astronomy): 

    "I tested the FMA135 with an 8mm 60-degree BST eyepiece. I screwed on the included 1.25" eyepiece holder to the field flattener that was already present at the back end of the scope, then plugged in the eyepiece. It was easy to adjust and come to focus with the helical focuser.

    I looked at nearby and far away objects as well and was amazed by the clarity, sharpness and complete lack of chromatic aberration even at the very edge of the field.  This might be the smallest and very best apochromatic quality spotting scope or APO refractor telescope in the world!

    I also tried to use it with a 1.25" Televue mirror diagonal by removing the flattener, but could not come to focus, The Televue diagonal has quite a long eyepiece holder, so we will try other options later to see if we can create a configuration for an angled finderscope setup.

    I'll now pass this onto one of my colleagues to test it with various cameras to see how it will perform as an astro photo instrument. Will come back with the result shortly."

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