SAFR SCAN recommended mounting height is from 48 to 58 inches. Lower mounting down to 42" (existing ADA compliant reader heights) or 38" (Turnstiles) is possible but will result in slower response time and perform better when users stop and look at the device at the right distance. While a walk-thru experience can be achieved with readers mounted near or at face level, this is typically not possible with the lower mounting. This document outlines the trade-off between reducing installation costs by mounting to existing reader cutouts and user experience. This also applies to Turnstile mounting which is often dictated by the height of the turnstile.
When mounted at 42 inches, a 30° upward title angle is found to be optimal in order to have face near center of view when at the distance required for liveness verification (3 to 4 feet). Attached videos demonstrates behavior when at 42” height. What we see is that SCAN is able to match the face and verify liveness, but usability suffers a little compared to readers mounted at 55". At 42" mounting height, people need to stand a moment at the right distance. In contrast, when reader is 55” (face high), access granted typically occurs as the person approaches and offers a smoother flow.
Because the reader is angled at 30°, there is a specific sweet spot where liveness verification occurs. The user needs to stop at a specific point. To make this more natural and avoid case where person walks up too close, positioning the reader to the location where the person is right in front of the door holding the handle works to ensure the correct location of the person (see above video for example).
Most users find the experience with the lower mounted reader to be acceptable. For some the low angle view can be an unflattering pose. A few users not familiar with facial recognition readers tend to crowd the reader when mounted at the lower angle. This tends to be less of an issue for readers mounted at face height.
For fastest performance / best user experience, reader should be inline with the approach vector of a person and at face height.