Patent ID: 6962447

Claim:
A single-lens reflex camera comprising: a screen on which an image of an object is projected; a plurality of reflection surfaces for erecting the image on the screen; and an eyepiece system with positive refracting power for observing the image, wherein the eyepiece system comprises, in order from an object side, a first lens component with positive refracting power, a second lens component with positive refracting power, and a third lens component with negative refracting power so that spacings between the first lens component and the second lens component and between the second lens component and the third lens component are changed to thereby make a diopter adjustment, and the single-lens reflex camera satisfies the following conditions: 0.15<tan( S )<0.35 2.00 <fb/Y< 4.00 −0.80 <f 3 / f<− 0.40 where S is an angle, at a diopter of 0 m −1 , made by a most off-axis chief ray passing through a point on an optical axis at a distance of 23 mm along the optical axis from an exit surface of the third lens component with the optical axis; fb is an air-equivalent length, at a diopter of 0 m −1 , from the screen to an entrance surface of the first lens component; Y is a diagonal length of a picture plane on the screen; f 3 is a focal length of the third lens component; and f is a focal length, at a diopter of 0 m −1 , of an entire system from the screen to an exit surface of the eyepiece system.