These binoculars are equipped with an auto focus feature and an excellent balance of magnification and aperture. Designed for marine use, its classic 7x50 model provides an optimal balance of magnification and aperture. Binoculars with increased magnification are harder to hold steady which may cause the image to appear blurry, whereas a smaller lens would decrease aperture, causing the image to appear darker. This model features BK 7 prisms and extended eyecups that are useful for users with glasses. Linear field refers to the width of the area seen when observed at the distance of 1,000 m. With a field of view of 7,1 degrees, the linear field is 119 m at 1,000 m.