Visible differences between my Nikon FM (1980) and my Nikon FM2n (2001)
  1. FM2n has max shutter speed of 1/4000, vs 1/1000 for FM
  2. FM2n has max flash sync of 1/250, vs. 1/125 for FM
  3. FM2n has viewfinder readylight for flash. FM doesn't.
  4. FM2n has extra contact on hot shoe for viewfinder readylight, and insulated plastic part of hot shoe is bigger and rectangular, vs. "keyhole" shaped insulated area on FM hot shoe.
  5. FM2n has user-changable focusing screens. FM requires a technician to change the screens.
  6. Meter is switched differently. FM2n requires light pressure on shutter release to turn on, turns off automatically after 30 sec with no pressure. FM meter is on when film advance lever is in "stand-off" position, off when advance lever is flush with back.
  7. FM2n's meter is switched off when shutter is on "B" (saving battery and preventing LEDs from fogging film during ultra-long exposure). FM's meter stays on (B meters like 2 sec shutter speed)
  8. FM has red dot on top plate in a position so that it's exposed when the film advance lever is in the "stand-off" position where the meter is switched on.
  9. FM accepts either Nikon/Leica or ISO cable release. FM2n only accepts ISO cable release, but has bigger shutter release button.
  10. FM has metal AI coupling prong that can be swung out of the way to accept non-AI lenses. FM2n has plastic AI coupling prong that cannot accept non-AI lenses, and will be damaged if non-AI lenses are mounted.
  11. FM2n has internal contacts for databack. FM doesn't.
  12. FM2n has "FM2" on front. Serial number begins with "N". FM serial number begins with "FM", and this is the only place on the entire camera where the letters "FM" appear.
  13. Self timer lever is different. The pivot point is closer to the lens mount on the FM2n, and the lever is slightly offset.
  14. DoF preview lever is slightly different. FM2n's is scalloped with a "stairstep" design, while FM's is smooth.
  15. The "Nikon" emblem on the prism is in slightly bolder type on the FM2n, and it's engraved slightly deeper.
  16. FM has red numbers on frame counter at 0, 20, and 36. FM2n has no '0' marked on its frame counter, and has red numbers at 1 (the only odd number on either camera's frame counter), 12, 20, 24, and 36.
  17. FM's frame counter window is above the surrounding metal. FM2n's window is flush with the metal.
  18. FM's film speed dial is marked "ASA". FM2n's is marked "ASA/ISO"
  19. FM2n's film speed has red numbers at 100 and 400. FM has no red numbers.
  20. FM's multi-exposure button is sort of between the shutter speed dial and the prism. It's a round "wedding cake" shape, made of three disks. You slide it toward the prism to activate. FM2n's multi exposure lever is black plastic, concentric with film advance lever. Slide back and to right (clockwise) to activate.
  21. FM2n has stylized "CE" logo on bottom plate. FM doesn't.
  22. FM2n has plastic film reminder holder on back. FM has metal one (FM's metal film reminder holder is made of brass covered by black paint, and where the black is worn off is the only actual brass color visible on the camera.)
  23. Film advance lever is black on FM2n, chrome on FM.
  24. Collar around base of shutter speed dial is metal on FM, plastic on FM2n.
  25. Collar around shutter release is metal on FM, plastic on FM2n.
  26. Collar around rewind crank (which is used to release the crank to open the back) is metal on FM, plastic on FM2n.
  27. Arrow on rewind crank is bolder on FM2n than on FM.
  28. Shutter speed dial knurling is different. FM2n has only vertical score marks, while FM has both vertical and horizontal scoring.
  29. Fillet radius is smaller (corners are sharper) on corners of prism and area below lens mount of FM.
  30. Front "mask" which covers the front of the prism, down to the area surrounding the lens mount, is metal on FM, plastic on FM2n. Appearance is very similar, however.
  31. FM's pressure plate is smooth. FM2n's has little dot pattern.
  32. FM shutter has 5 blades visible on first curtain, 3 on second. FM2n has four blades visible on each curtain.
  33. Area where film cannister sits is a bit squared-off in the FM2n, totally rounded in FM.
  34. Meter readout LEDs are + o - on FM2n, while the FM has little dot LED's, with + o - legend symbols next to the LEDs, intruding slightly into the image area of the viewfinder.
  35. Baffling on "film advance lever" side of mirror box is smooth on FM2n, vertically ridged on FM.
  36. Battery holder on FM is marked 1.5Vx2 on one side, with a pictoral representation of 2 cells on the other. Battery holder on FM2n is marked 1.5Vx2 with picture of 2 cells on one side, and marked 3Vx1 with pictoral representation of 1 bigger cell on other side.