ASKAR FMA230 F230 f/5.5 Astrograph Camera Lens - Triplet APO Refractor Telescope with f/4.6 reducer

ASKAR FMA F230 f/5.5 Astrograph Camera Lens - Triplet APO Refractor Telescope with f/4.6 reducer

The ASKAR FMA230 objective lens features a triplet air-spaced APO design, includes two pieces of ED (extra-low dispersion) glass, providing excellent correction of chromatic aberration, which lays the foundation for high quality astrophotography and observation.

The FMA230 has a compound lens system. The front objective lens comprises three lenses and the posterior reducer is composed of four lenses and thus it’s sometimes dubbed as a “three at the front and four at the rear” system. The aperture size of the objective lens is 50mm and the original focal length is 275mm thus we’ve got a relatively fast focal ratio of f/5.5. The objective lens contains two ED glasses which are adapted to cure chromatic aberrations.

One can barely find an equal counterpart in the market as designing a three-element apochromatic objective lens in astrograph with such size demands more on craftsmanship and processing technique. We made it because we consistently cling to the belief that we have to deliver a better imaging result to our customers. The FMA230 can solely function as a lens to observe the ground scenery or stars in the sky, or as a telescope for direct-focus photography. You should just fine-tune the helical focuser to perfectly focus without adding extra optical devices.

The four-element reducer is a 0.84×optical device which can change the the FMA230 into a 50mm-aperture astrograph with a focal length of 230mm and a focal ratio of f/4.6. The reducer is designed specially for sophisticated astrophotography, which plays an essential role in improving the image quality generally across the whole field of view. And it pays special attention to the stars at the edge of the image. The pictures will be greatly enhanced and detailed under the help of this dedicated reducer even the imaging equipment you use is a rather professional full-frame ordinary or astronomy camera.

SPECIFICATIONS

• Aperture: 50mm
• Focal Length: 275mm or 230mm (with reducer) 
• Focal Ratio: f/5.5 or f/4.6 (with reducer)
• Objective type: Triplet Dual ED air -spaced APO (objective lens only) or Sextuplet APO Refractor (with reducer)
• Overall length: 248mm (when imaging with the reducer) or 221mm (when observing without the diagonal)
• Weight: 1045g
• Back-end adapter:
  • M48x0.75 male thread (photographic mode),
  • 2" eyepiece holder barrel (observation mode)

WHAT'S IN THE BOX

• FMA230 body
• a pair of multi-directional tube rings
• utility-handle (that also serves as a multi-purpose finderscope bracket)
• two extension tubes
• instruction manual
• 2" adapter (2" eyepiece holder)