Photography & Optics: Depth of Field & Exposure Guide
Hyperfocal distance, crop factors, exposure values, and video storage requirements.
📚 Overview
Photography blends artistic vision with optical geometry. Mastering the exposure triangle (aperture, shutter speed, ISO), sensor crop factors, and depth of field allows photographers and cinematographers to achieve sharp, cinematic imagery in any lighting environment.
📐 Hyperfocal Distance & Exposure Value (EV)
Where f is focal length, N is aperture f-number, c is circle of confusion (e.g. 0.03mm for full frame 35mm), and t is shutter speed in seconds.
🔢 Worked Example
Scenario: A landscape photographer using a 24mm lens at f/8 on a full-frame sensor (c = 0.03mm).
- Focal Length: 24 mm
- Aperture: f/8
- Circle of Confusion: 0.03 mm
- Numerator = 24² = 576
- Denominator = 8 × 0.03 = 0.24
- Hyperfocal distance = 576 / 0.24 = 2,400 mm = 2.4 meters (7.9 ft)
💡 Pro Tips
- Closing down aperture beyond f/11 or f/16 on high-resolution sensors introduces optical diffraction softness.
- Multiply focal length and f-number by your sensor's crop factor (1.5x for APS-C, 2.0x for Micro Four Thirds) to find 35mm equivalent field of view and depth of field.
- Follow the 180-degree shutter rule for video: set shutter speed to 1/(2 × frame rate) for natural motion blur (e.g. 1/50s for 24fps).
- Use our photo storage calculator to determine how many raw photo files fit on memory cards.
🧮 Photography Calculators (30)
Put the formulas above into practice with these free tools:
Convert aperture, shutter speed, and ISO into an exposure value.
Near and far limits of acceptable sharpness for any lens setup.
Find the focus distance that keeps everything to infinity sharp.
Crop factor and full-frame equivalent focal length and aperture.
Horizontal, vertical, and diagonal angle of view for a lens and sensor.
Slowest shutter speed you can hand-hold without blur.
New exposure time after adding a neutral density filter.
Compare two exposure settings and see the difference in stops.
❓ Frequently Asked Questions
What is the exposure triangle?
The balance between Aperture (depth of field), Shutter Speed (motion blur), and ISO (sensor signal amplification and noise).
What does depth of field depend on?
Aperture f-number, focal length, distance to the subject, and the camera's physical sensor format.
How is video bitrate converted to gigabytes per hour?
Multiply bitrate in Mbps by 3,600 seconds, then divide by 8,000 to get Gigabytes per hour (e.g. 100 Mbps ≈ 45 GB/hour).