FlashroomDigital booths
Depth of field and depth of focus describe different sides of a lens
One concerns the subject; the other concerns the sensor position.
The similar names are easy to confuse when diagnosing a soft photobooth camera. Separating them helps you decide whether to adjust subject placement or inspect the camera’s sensor and lens alignment.
Subject-side range
Depth of field describes the range of object distances that retain a chosen image quality without refocusing. Its useful range depends on how much resolution and contrast the final strip needs, so a casual screen preview and a close print inspection can lead to different judgements.
Evidence: Optics engineering guide
Image-side tolerance
Depth of focus describes the sensor’s tolerance around the image plane while maintaining focus. A sensor or mount shifted from the designed position can soften the image even if guests stand exactly at the marked distance.
Evidence: Optics engineering guide
Choose the right check
If only guests at different distances are soft, test subject placement and depth of field. If a fixed target is soft across every distance or one side stays soft, have the camera mount and lens alignment checked by a qualified technician rather than changing guest positions indefinitely.
Sources & further reading
Sources for the specific facts and product descriptions above. Our worked examples, interpretations and practical suggestions are original editorial guidance.
- Edmund Optics, Depth of Field and Depth of FocusOptics engineering guide