Hi Dan,
There are a few ways to increase magnification but they all require somewhat of a redesign on the Miniscope housing and optics. In general, the longer the focal length lens you use for the tube lens, the larger the magnification will be. At a focal length of 15mm, we get a magnification of around 6 to 7x. We often run with a focal length of 20mm and this gets us to a magnification closer to 9x. You could keep going up in focal length but this also requires the CMOS imaging sensor to be mounted higher up to get the same range in focal planes.