The Rokinon 135mm f/2.0 ED UMC lens from Rokinon is especially well-suited to astrophotography. At Deep Sky West Remote Observatory (DSW) we use the Rokinon as part of a fully automated astrophotography system. The fast f/2 maximum aperture makes the Rokinon 135 especially effective at capturing the elusive photons of the night sky.
Even wide open at f/2 the extra-low dispersion glass and overall optical design delivers sharp, round stars across the field with no hint of chromatic aberration. In our experience, no other camera lens combines the speed and image quality of the Rokinon–especially at this price point. The Rokinon is so fast that even short 5-minute unguided exposures are sufficient to produce images like the ones below. The Rokinon rivals the performance of high-quality, purpose-built small refractors, but at a fraction of the price. It is equally at home on a DSLR as it is on a specialized cooled CCD camera. It many respects it is the best “first telescope” for beginners. For experienced astrophotographers it provides a new level of price / performance for extremely wide-field imaging.
Our production Rokinon 135 astrophotography system is shown at right. A power distribution system located just in front of the lens hood provides power for the automated focuser, dew heater and CCD camera. The CCD camera (black and blue case) is solidly connected to the lens via Nikon mount and a telescope ring holds the front of the lens for additional stability. The entire imaging platform weighs ~12 pounds making it light enough for even modest telescope mounts.
Below are a few examples of the excellent results achieved with the Rokinon 135. Special thanks to Roberto Colombari and Paddy Gilliland for contributing their images and superior processing skills. The images were captured remotely via the Internet at Deep Sky West Remote Observatory. DSW’s combination of darkness, astronomical seeing, and transparency ensures this equipment is at its highest and best use:
- Rokinon 135mm f/2
- QSI 583 wsg-5 CCD Camera
- Paramount ME German Equatorial Mount
- Robofocus Stepper Motor Focuser