Aspect Ratio: The Shape of Your Image
The aspect ratio defines the width/height proportions of the image. 3:2 (standard photo, panoramic) is dominant among DSLRs and mirrorless cameras. 4:3 (more balanced) is used by Micro 4/3 systems. 16:9 is reserved for video.
Sensor Format: The Physical Size
The physical size of the sensor is crucial for image quality, depth of field, and lens performance.
| Full Frame | APS-C | Micro 4/3 | |
|---|---|---|---|
| Size | 36 x 24 mm | 23.6 x 15.7 mm | 17.3 x 13 mm |
| Crop Factor | 1x | 1.5x | 2x |
| Low Light Performance | Excellent | Very Good | Good |
| Housing Size | Large | Medium | Compact |
| Housing Cost | 2000-4000 EUR | 1000-2500 EUR | 800-1500 EUR |
| Ideal for | Professionals, low light | Versatility, travel | Travel, video, macro |
Underwater Applications
In underwater photography, compactness is a significant advantage: less drag in currents, easier handling to frame moving subjects, and lighter weight for travel. The Micro 4/3 system is very popular among traveling divers. APS-C offers an excellent compromise. Full Frame systems are ideal for professionals working in low light conditions.