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.