Find a lens for this look
eBay links may earn us a commission, at no extra cost to you.
Matching lenses from each maker's lineup, plus some classic medium and large format lenses. Email me if something is wrong or missing.
Nikon AF 28mm f/2.8D — Bokeh & Optical Ray-Tracing Simulator
Interactive 3D portrait ray-traced through the published US5557473A optical prescription (6 elements in 6 groups) with a 10.0 mm entrance pupil and 0.25 m minimum focus.
Optical & Portrait Specifications (Upper Body Framing)
| Optical & Portrait Metric | Measured / Patent Value | What It Means in Practice |
|---|---|---|
| Patent Prescription | US5557473A · 6 elements in 6 groups | Traced surface by surface in WebGL2 |
| Entrance Pupil Diameter | 10.0 mm (at f/2.8) | Controls distant background blur disc size |
| Corner Bokeh Roundness (90% Field) | 60% at f/2.8 (≥86% from f/5.6) · -1.1 EV | Mechanical vignetting (cat’s-eye vs. round corner highlights) |
| Background Field of View (Compression) | 66° horizontal | Width of the background room visible behind the subject |
| Upper-Body Working Distance | 1.15 m | Camera-to-subject distance for head-to-waist framing |
| Effective Focal Length (Breathing) | 27.6 mm (-1.3%) | Actual framing focal length at portrait distance |
| Depth of Field (Sharp Zone) | 42 cm (97 cm – 1.40 m) | Sharp zone at wide-open aperture |
| Minimum Focus Distance | 0.25 m | Closest focusing distance from the sensor |
Questions
How much background blur and corner cat's-eye does the Nikon AF 28mm f/2.8D produce?
Wide open at f/2.8, the Nikon AF 28mm f/2.8D has a 10.0 mm entrance pupil (28 mm ÷ 2.8) and 60% bokeh roundness in the 90% corner (-1.1 EV corner falloff, reaching ≥86% roundness from f/5.6). In an upper-body portrait at 1.15 m, the sharp depth-of-field zone spans 42 cm (97 cm to 1.40 m) with a 66° horizontal background angle of view.
Does the Nikon AF 28mm f/2.8D show focus breathing at portrait distance?
Based on patent US5557473A, tracing the focusing group at 1.15 m gives an effective framing focal length of 27.6 mm (-1.3% vs. the nominal 28 mm). You can toggle "Match subject size" in the simulator to see the framing shift live.
What optical design is inside the Nikon AF 28mm f/2.8D?
The patent prescription (US5557473A) specifies 6 lens elements in 6 groups. The interactive Optical X-Ray above traces rays through every surface in real time.
Related comparisons
- Nikon 28mm f/1.4E FX
- Nikon AF 28mm f/1.4D
- Nikon 28mm f/2.0
- Nikon 28mm f/2.8 AI-s
- Nikon 28mm f/3.5
- Nikon 24mm f/1.4G FX
Compare with similar portrait lenses
- Nikon NIKKOR Z 28mm f/2.8
- Canon RF 28mm F2.8 STM
- Leica Elmarit-M 28mm f/2.8 ASPH.
- Nikon NIKKOR Z 20mm f/1.8 S
Also see: depth of field, bokeh, crop factor, lens compression.