Nikkor 24mm f/2.8 N non-AI ('67-'77, this sample circa '70)
Filter size: 52mm
Close focus distance: 1 foot or 0.3 meters (marked)
Aperture range: f/2.8 - f/16
Aperture blades: 6
Depth of field scale for f/4, 8, 11, 16 plus IR focusing index.
Design: 9 elements in 7 groups
More information: Nikkor Thousand and One Nights
This is the first Nikkor lens with close range correction or CRC. Mine has the factory AI conversion. It is a solid lens - it is actually a little too well-behaved and modern looking for my taste.
More photos from this lens: