Theses collar can slide forward and back. This allows optimal focus and image size. Movement finds the perfect focus for any slit lamp.
Place the EyePhotoDoc onto the collar and gently move the collar with the Apple device back and forth until it is the optimal focus. Tighten set screw. See below
Collar installation for Haag-Streit, Zeiss, CSO with sliding glare guards
In order to get proper centration, the rarely used glare guard needs to be removed. All of he glare guards pull off by extending them and rocking it until it comes loose. Remove the keeper spring and place the collar on.