Ricoh has a new patent for a 23mm and 28mm f/2.8 APS-C lenses designed for a compact camera (new Ricoh GR maybe?):
Embodiment 1:
f = 25.99 mm,F = 2.86,ω = 28.3Embodiment 7:
f = 23.42 mm,F = 2.88,ω = 30.9Other Embodiments:
2: f = 26.05,F = 2.87,ω = 28.3
3: f = 26.05,F = 2.87,ω = 28.3
4: f = 28.00,F = 2.88,ω = 26.6
5: f = 26.05,F = 2.88,ω = 28.3
6: f = 24.68,F = 2.88,ω = 29.6
8: f = 26.04,F = 2.88,ω = 28.3
9: f = 26.06,F = 2.88,ω = 28.3
10: f = 26.05,F = 2.88,ω = 28.3
Via hi-lows-note