Professional DSLR & Mirrorless Camera Companion
Manual photography requires calculating three interdependent camera settings (ISO, aperture, shutter speed) to achieve proper exposure. This is challenging because:
Exposure IQ solves this using the APEX-CAL™ constraint-solver engine, a deterministic mathematical system that calculates optimal camera settings in real-time by:
Unlike heuristic or compensation-based approaches, Exposure IQ uses deterministic constraint solving with the fundamental exposure equation:
Scene EV = Av + Tv + Sv
Where Av = 2·log₂(f), Tv = log₂(1/t), Sv = log₂(ISO/100)
Vision framework for face detection, scene classification, brightness measurement from EXIF BrightnessValue, motion detection for action photography
All calculations in logarithmic base-2 space. Third-stop snapping to real camera detent positions. Algebraic solving for unknown parameters
Each mode defines anchor (creative control), helper (technical requirement), release valve (absorbs deficit). Priority-based violation handling
Lens database with focal length, max aperture, stabilization. Camera body sensor formats (full-frame, APS-C, Micro 4/3). IBIS/OIS aware shutter calculations
| Mode | Anchor (Priority 1) | Helper (Priority 2) | Release Valve (Priority 3) | Use Case |
|---|---|---|---|---|
| General | None | Shutter, Aperture | ISO | Point-and-shoot balanced exposure |
| Portrait | Aperture (f/1.4-f/2.8) | Shutter (1/125s) | ISO | Shallow depth-of-field, bokeh background |
| Landscape | Aperture (f/8-f/16), ISO (100-200) | None | Shutter | Maximum depth-of-field, sharpness throughout |
| Action | Shutter (1/500-1/2000s) | Aperture (f/2.8-f/5.6) | ISO | Freeze motion, fast-moving subjects |
| Low Light | Aperture (wide open) | Shutter (safe min) | ISO | Indoor photography, dim restaurants, twilight |
| Macro | Aperture (f/8-f/16) | Shutter (1/125s) | ISO | Close-up detail with extended focus plane |
| Astrophotography | Aperture (widest), Shutter (500-rule) | None | ISO | Stars, Milky Way, night sky (prevents star trails) |
| Night Photography | Aperture (wide open) | None | ISO | City lights, long exposure, fireworks, blue hour |
| Aperture Priority | Aperture (user-set) | Shutter (flexible) | ISO | Manual DOF control, learning aperture effects |
| Shutter Priority | Shutter (user-set) | Aperture (flexible) | ISO | Manual motion control, sports, water effects |
Learn exposure triangle relationships. See real-time stop calculations. Understand constraint trade-offs. Coaching tips explain why specific settings are recommended.
Maintain 1/48s or 1/50s shutter for 24fps video. Calculate ND filter strength needed. Monitor exposure as lighting changes during takes.
Adapting from full-frame to APS-C or Micro 4/3? Understand how crop factor affects depth-of-field and effective aperture for equivalent look.
Quick exposure checks when moving between indoor/outdoor. Action mode for sports. Portrait mode for posed shots. Gear recommendations when lighting gets challenging.
Calculate hyperfocal distance for maximum sharpness. Determine if scene requires bracketing. Check if ND filter needed for long exposures.
Milky Way, star trails, night sky landscapes. 500-rule prevents star trails. Dual anchors (widest aperture + proper shutter) maximize light gathering.
City lights, skylines, light painting, fireworks. Supports exposures up to 30s. Wide aperture priority with ISO compensation.
Indoor without flash. Restaurants, bars, museums, twilight. Prioritizes wide aperture, accepts higher ISO for proper exposure.
Learning manual control one parameter at a time. Set your f-stop or shutter speed, app calculates the rest. Perfect for transitioning from auto to full manual.
Transitioning from auto to manual? See exactly what your camera's auto-exposure would choose, then understand why as you adjust across 10 modes.
General photography mode with basic exposure recommendations
All 10 professional photography modes plus advanced features
Try all Pro features free for 3 days, cancel anytime
Exposure IQ is built with a "privacy-first" philosophy because your photography is personal.
Every feature runs locally on your iPhone:
Absolutely nothing. The app is fully functional offline after initial download from App Store.
Questions? Contact developer via GitHub profile.
Exposure IQ uses the same APEX (Additive System of Photographic Exposure) mathematics that cameras use internally. Recommendations match what professional photographers would manually calculate, typically within 1/3 stop. The constraint-solver ensures the fundamental equation Scene EV = Av + Tv + Sv is always satisfied.
No, it's a companion tool for manual shooting. Your camera's meter measures the scene, Exposure IQ calculates optimal settings for your creative intent. It's like having a photography instructor explaining the reasoning behind each recommendation.
Yes! The exposure triangle mathematics are identical for film. Since the app doesn't require taking photos (just analyzing the scene), it works as a spot meter and exposure calculator for any manual camera.
Exposure IQ has its own camera preview for analysis but doesn't capture photos. Use it to determine settings, then switch to your preferred camera app (Halide, ProCamera, native Camera) to shoot with those calculated values.
Modern mirrorless and DSLR cameras have excellent auto-exposure. Exposure IQ is for photographers who want to learn or shoot manual mode, understand exposure trade-offs, or work in challenging lighting where auto-exposure struggles (backlit subjects, snow/beach scenes, low-light events).
When faces are detected, the app adjusts aperture recommendations based on subject count and estimated distance. Single subject at 2m: recommends f/1.8 for maximum bokeh. Three subjects: suggests f/2.8 to keep all faces sharp. This is depth-of-field physics, automated.
Night Photography is for city lights, long exposures, light painting, and fireworks. It allows shutter speeds up to 30 seconds and prioritizes wide aperture while letting ISO compensate.
Astrophotography is specifically for stars and the Milky Way. It uses the 500-rule to prevent star trails (500 ÷ effective focal length), forces widest aperture, and accepts high ISO (3200+). The key difference is shutter speed limits to avoid star movement.
Aperture Priority is for when depth-of-field is your primary creative concern. You set the exact f-stop you want (e.g., f/1.4 for portraits), and the app calculates shutter speed and ISO to match. Great for learning how aperture affects your images.
Shutter Priority is for when motion is your focus. You set the exact shutter speed (e.g., 1/2000s to freeze sports action, or 1/4s for water blur effects), and the app calculates aperture and ISO. Perfect for sports, wildlife, or creative motion photography.
Yes, the gear library persists your camera body and lenses. Calculations automatically account for sensor format (crop factor), maximum aperture limits, and stabilization (IBIS/OIS) for shutter speed recommendations.
If you're in Portrait mode at f/1.8 (anchor), and the scene requires 1/125s minimum shutter (helper), ISO becomes the only variable that can adjust. In low light, this might mean ISO 3200 or higher. The app warns when this happens and suggests switching to a faster lens if you want lower ISO.
Yellow warning: Helper constraint violated (e.g., shutter slower than sharp-hand-holding minimum). Photo is possible but may have technical issues. Red warning: Anchor constraint violated (e.g., can't achieve f/1.4 with f/1.8 lens). Impossible without different gear. App recommends specific equipment to resolve.
Developer: Alan Hermann (@ajhermann94)
Exposure IQ represents a complete architectural rewrite, transforming from a heuristic compensation-based system to a deterministic constraint-solver. The original version used arbitrary reference points (EV 10.0) and could produce mathematically impossible recommendations. The current APEX-CAL™ engine replaced approximately 500 lines of error-prone logic with a mathematically rigorous solver that:
Exposure IQ is proprietary, but the mathematical foundation is based on the APEX standard (ANSI PH2.7-1986). The constraint-solver algorithm is original work but draws inspiration from academic research in combinatorial optimization and photographic science.
Bug reports, feature requests, and technical questions: GitHub profile