GOAT LabLensLab: 16 offline depth of field, ND & exposure calculators
LensLab is a free, fully client-side set of 16 photography and optics tools — depth of field, hyperfocal distance, ND filter exposure, astro shutter timing, flash guide number, print size, time-lapse and panorama planning — that run instantly in your browser. All results are estimates from thin-lens optics and standard photographic conventions; verify critical shots in the field.
- Free
- No sign-up
- Works offline
What is LensLab?
LensLab bundles 14 everyday photography and optics calculators plus 2 reference tables across four areas: lens & focus (depth of field, hyperfocal distance, field of view, crop-factor equivalence, macro magnification, pixel-pitch diffraction), exposure & light (ND filter exposure, astro shutter NPF/500 rule, flash guide number, EV & Sunny 16), and shoot planning (print size, time-lapse, memory card capacity, panorama shot count) — plus a sensor-format chart and an ND filter stop chart. Everything is computed locally with no server, no account, and no upload.
How does it work?
Each calculator runs as client-side JavaScript using standard photographic formulas — for example hyperfocal distance H = f²/(N×c) + f, the NPF astro rule t = (35N + 30p)/f seconds, and new ND-filtered shutter time T' = T × 2^S. Every calculator shares one internal sensor-format table (crop factor = 43.27/diagonal, circle of confusion = diagonal/1442), so results stay consistent whether you pick full frame, APS-C, Micro Four Thirds, or a phone sensor.
When should I use it?
Use LensLab to check a lens's depth of field before you buy, work out how long to leave the shutter open behind a 10-stop ND filter, find the longest exposure before stars trail using the NPF rule, size a print from your camera's megapixels, or plan the shot count and storage for a time-lapse or panorama. Estimates only — thin-lens optics and standard conventions, not a substitute for a test shot in the field.
At a glance
| Calculators | 16 (14 calculators + 2 reference tables) |
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| Areas | Lens & focus, exposure & light, shoot planning |
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| Sensor formats | 9, medium format to phone 1/2.55″ (shared table) |
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| Conventions | DOFMaster CoC, NPF rule (PhotoPills form), Sunny-16 |
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| Reference tables | Sensor format & crop-factor chart, ND stop chart (ND2–ND100000) |
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| Processing | 100% client-side — no server, no upload |
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| Account | None — free, no sign-up, works offline |
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| Languages | en, ja, es, zh, de |
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Frequently asked questions
How do I calculate depth of field?
Depth of field comes from the hyperfocal distance H = f²/(N×c) + f, where c is the circle of confusion for your sensor format. For a full-frame camera at 50 mm, f/2.8, focused at 3 m, LensLab returns a near limit of 2.73 m and a far limit of 3.33 m — a total depth of field of 0.60 m.
What is the NPF rule for astrophotography?
The NPF rule (t = (35×N + 30×p)/f seconds, p = pixel pitch in µm) gives a stricter maximum shutter time than the old 500 rule before stars trail. On a 24 MP full-frame body at 20 mm, f/1.8, LensLab calculates 12.2 s under NPF versus 25 s under the 500 rule — nearly half the exposure time.
How much longer should my shutter stay open with a 10-stop ND filter?
Multiply the base shutter speed by 2 raised to the number of stops. A 10-stop (ND1000) filter adds 9.97 stops, so a 1/60 s base exposure becomes about 16.7 s. LensLab includes a built-in countdown timer for the new time.
Is my data uploaded?
No. Every calculation runs entirely in your browser. Your inputs never leave your device.
Do I need an account?
No. LensLab is free, needs no sign-up or install, works offline once loaded, and is available in English, Japanese, Spanish, Chinese and German.
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