Finder unit

A finder unit comprising:

• a finder optical system having an objective optical system for forming a viewing image and an eyepiece optical system for viewing said viewing image, and including an inverting optical system for making the viewing image formed by said objective optical system an erecting normal image;
• a visibility adjustment mechanism for adjusting viewing visibility of said viewing image within a prescribed range;
• a first optical component which forms a part of said objective optical system and which is provided closer to said objective optical system such that it is distant from the image formation position for said viewing image by a predetermined length;
• and
• a second optical component which forms a part of said is eyepiece optical system and which is provided closer to said eyepiece optical system such that it is distant from the image formation position for said viewing image by a predetermined length;
• wherein both conditions are expressed by
• 4+X1<1000×D1/f2,
• and
• 4+X2<1000×D2/f2
• are satisfied, where f (mm) represents a focal length of said eyepiece optical system, D1 (mm) represents a distance from image formation position for said viewing image to an optical surface of said first optical component on the side of the image formation position for said viewing image, D2 (mm) represents a distance from image formation position for said viewing image to an optical surface of said second optical component on the side of the image formation position for said viewing image, X1 (1/m) represents an amount of adjustment toward visibility minus side of said visibility adjustment mechanism, and X2 (1/m) represents an amount of adjustment for increasing the visibility of said visibility adjustment mechanism.