300mm F6.3 for DSLR's


  • Full Frame
  • Low CA
  • Low Flare & Ghost
  • Catadioptric
  • Low Coma
  • Rokinon Multi-Coating
  • Compact for MILC

User manual can be downloaded here: Download

The Rokinon Reflex 300mm f/6.3 ED UMC CS Lens is a mirror lens designed specifically for use on Fujifilm X mirrorless cameras. The lens' Cassegrain design enables it to achieve a 450mm 35mm-equivalent focal length perspective within a compact and lightweight lens design that is significantly smaller than a traditional 300mm lens. It features a fixed f/6.3 aperture and utilizes manual focus operation for focusing as closely as 2.95'.

One extra-low dispersion element and the inherent mirror construction of the lens work to eliminate chromatic aberrations while providing notable image sharpness and clarity. Furthermore, the UMC (Ultra Multi Coated) coating has been applied to reduce surface reflections, lens flare, and ghosting while also contributing to improved overall contrast.

  • Mirror lens designed specifically for Fujifilm X mirrorless cameras.
  • Catadioptric system with Cassegrain design helps to reduce the overall size of the lens while still providing a 35mm-equivalent focal length of 450mm.
  • One extra-low dispersion element and a UMC coating are integrated into the lens construction to improve sharpness and clarity as well as enhance the overall image contrast.


Model: 300M-C
MSRP: $399
UPC: 0-84438-76276-1
Focal Length: 300mm
Maximum Aperture: F6.3
Coverage: APS-C
Optical Construction: Reflex Mirror (Catadioptric) 8 Glass Elements in 8 Groups
Aperture Range: F6.3 Fixed
Diaphragm Blades: n/a
Coating: Ultra Multi-Coating
Minimum Focusing Distance: 3.6ft (1.1m)
Filter Size: 58mm/25.5mm
Lens Hood: Removable
Maximum Diameter: 2.54” (64.5mm)
Weight: 9.5oz (270g)
Length: 3.0” (76.1mm)
1. Rokinon MTF charts use theoretical equations to plot performance and do not rely on subjective 
opinion, subject matter, camera features, software or other factors. They plot the contrast and resolution of a lens from the center to its edges, against a "perfect" lens that would transmit 100% of the light that passes through it. The contrast of a lens is important because it directly relates to resolution.

3. Rokinon tests are carried out with the lens at its maximum (widest) aperture (Ex. 24mm F1.4 lens is measured at F1.4 for MTF).

4. Zero on the chart’s X-axis (horizontal axis) 
represents the center of the lens. As a line moves right, it indicates the change of contrast and sharpness from the center to the edge of the image. 

5. The Y-axis (vertical axis) plots the transmission of light through the lens. It has a maximum value of "1.0" to indicate 100% transmittance of the light, which is not possible to achieve. 

6. The blue graph lines (10 lines/mm) represent contrast measurement. The red graph lines (30 lines/mm) represent resolution.

7. Sagittal lines (thick lines) represent the contrast 
measurements of line pairs that are parallel to an imaginary diagonal line that runs from the bottom left hand corner to the top right hand corner of a image frame. Meridonial lines (thin lines) represent line pairs that are perpendicular to the imaginary diagonal line.

8. The higher and straighter the blue lines, the better the contrast. The higher and straighter the red lines, the better the resolution.