Nikon's variable magnification angle finder for corner window viewfinders, the DR-6. The optics have some cloudiness (balsam separation?), but I think it's within a usable range. Instant purchase OK, no price negotiations. This is an angle finder for cameras with a corner window type viewfinder. Also, you can select from two magnifications: 1x and 2x. * At 2x, vignetting occurs in the periphery. * Diopter adjustment range: 1x magnification: -8.0 to +3.8 m-1; 2x magnification: -5.0 to +6.0 m-1