Premium Optical Device: Aluminum alloy material is used to make it last longer; perfect for broad-field lunar observations; medium-sized star clusters and a wide range of cloudy nebulae; obtaining better observation results during astronomical journey
50 Degree Field of View: 1.25 inch 4 mm plossl eyepiece set offers a wider 50 degree field of view and a 4 mm focal length for observing larger objects; giving the wider view field along with extra sharpness and long eye relief
Fully Muti-Coated Optical Lens: 4-Element Optical Lens; providing bright; sharp images and excellent color correction and the fully coated groups on each lens surface maximize light transmission; contrast; and image clarity
"Stop-down mode" will need to be used when metering since the lens does not have the ability to have its aperturecontrolled by the camera body
No ROM connection on the adapter; diaphragm control of the lens is set manually