The J-Mount Design
The J-Mount was developed to hold a smartphone in landscape orientation up to a microscope eyepiece. With any mount, there are 6-axes of movement to consider: X-axis, Y-axis, Z-axis, as well as pitch, roll and yaw.
The eyepiece barrel is designed to wrap around the outside of an eyepiece, taking care of the later 3 axes of movement.
The ribs within the eyepiece barrel hold the mount at the necessary Z-distance from the eyepiece lens to enable positioning in the correct focal plane. Two adapters are included that act as 'shims'; for those with thick cases, no shims are necessary, for those with a thin case, a thin shim can be used, and for those without cases, the thicker shim works best. The pins of the shims wrap around the ribs within the eyepiece, staying securely in place once positioned.
For Y-axis adjustment, a thumbscrew on the rear of the mount adjusts the phone shelf up and down; again, once the mount has been set for your phone, no further major adjustment is needed.
Lastly, for the X-axis, the phone is slid along the platform to place the camera in the optimal position.
A Wide Array of Smartphones
The J-mount comes in 2 sizing varieties in order to fit most microscopes and smartphones.
For those with modern professional grade microscopes produced by Nikon and Olympus, an eyepiece size of 3.6 cm is best. For those with microscopes which have smaller diameter eyepieces, the 2.6-3.6 cm eyepiece will work best. Additonally, it is best to remove any rubber protectors on the eyepiece to allow easy setup and removal of the J-Mount.
As currently designed, the J-Mount is designed to attach to the left eyepiece.