ApertureThe technical
craft of photography,
decoded.
Hyperfocal tables. Reciprocity failure charts. Sensor crop math. Diffraction limits. Every answer you need mid-shoot — no blog posts, no guessing.
Used by 4,000+ working photographers
Exposure Math & Sensor Formats
Toggle variables, hover rows, see equivalences instantly.
Exposure Equivalence
EV = log₂(N² / t) − log₂(ISO / 100)
| Shutter Speed | ISO | Aperture | EV | Scene |
|---|---|---|---|---|
| 1/4000s | 400 | f/2.8 | EV 12.9 | Overcast / shade |
| 1/2000s | 400 | f/2.8 | EV 11.9 | Overcast / shade |
| 1/1000s | 400 | f/2.8 | EV 10.9 | Indoor bright |
| 1/500s | 400 | f/2.8 | EV 9.9 | Indoor bright |
| 1/250s | 400 | f/2.8 | EV 8.9 | Indoor low light |
| 1/125s | 400 | f/2.8 | EV 7.9 | Indoor low light |
| 1/60s | 400 | f/2.8 | EV 6.9 | Night / dark |
| 1/30s | 400 | f/2.8 | EV 5.9 | Night / dark |
| 1/15s | 400 | f/2.8 | EV 4.9 | Night / dark |
↑ hover rows to highlight · equivalent exposures share the same EV
Crop Factor Comparator
35mm equivalent = focal × crop_factor
| Format | Crop × | 35mm Equiv. | Size mm |
|---|---|---|---|
| Medium Format | ×0.64 | 32mm | 53.4×40 |
| Full Frame | ×1 | 50mm | 36×24 |
| APS-H | ×1.3 | 65mm | 27.9×18.6 |
| APS-C (Nikon) | ×1.5 | 75mm | 23.6×15.7 |
| APS-C (Canon) | ×1.6 | 80mm | 22.3×14.9 |
| Micro 4/3 | ×2 | 100mm | 17.3×13 |
| 1" Type | ×2.7 | 135mm | 13.2×8.8 |
Optical Simulators
Drag sliders to see bokeh disk size and ND stacking results in real-time.
Bokeh Simulator
disk_diam = (f/N) × |z_bg − z_subj| / z_bg
ND Filter Stack
combined_factor = ∏ ND_factors
select_filters
Open the Full Reference.
Every tool you just used is the free tier. The full library contains hyperfocal tables for every format, MTF curve analysis, reciprocity failure charts for 30+ film stocks, lens projection geometry, and flash coverage calculators — all in one searchable, mid-shoot-optimized interface.
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200+ Tools in the Full Library
Complexity scales from basic exposure math to MTF analysis and lens projection geometry.
Flash Guide Number
GN = distance × aperture (ISO 100)
Color Temperature
Kelvin → Mired shift conversion
Diffraction Limit
f_diff = 1.22λ × (N+1) / pixel_pitch
Reciprocity Failure
Film speed correction for long exposures
Hyperfocal Tables
Complete H-distance lookup by format
MTF Curve Reader
Contrast vs. spatial frequency analysis
ND Filter Stacking
Combined stop reduction calculator
Lens Projection Geometry
Rectilinear vs. fisheye vs. equidistant
Locked tools unlock with Full Reference access.
Unlock All 200+ ToolsSettled a heated argument at the counter about whether f/11 is diffraction-limited on a 24MP MFT body. Aperture had the answer in 15 seconds.
Marcus Chen
Camera Store Manager, B&H NYC
I shoot weddings at f/1.8. Having the hyperfocal table pre-calculated for my 35mm on full frame means I never miss focus during a first dance again.
Priya Sharma
Wedding Photographer, Mumbai
The reciprocity failure charts for Kodak 400TX saved my whole night shoot series. I'd been underexposing by 2.5 stops for three years.
David Kowalski
Fine Art Film Photographer, Chicago