Abstract: A microscope system whereby microscopic specimens can be continuously and autonomously maintained in focus without sacrifice to the optimum resolution of the objective. The system achieves focus by splitting the image emerging from the objective lens into two pathways, a focus test pathway and an observational pathway. Each pathway contains an electronically indexed lens module. The focus test pathway lens module is continuously varied, resulting in focal variations in its projected image. The focus test pathway lens position is correlated with the focus camera image for optimum focus. The indexed value for the optimum focus, obtained from the focus test pathway, is then compared to the index value of the lens module in the observational pathway where immediate correction is applied if necessary. Therefore, time and three-dimensional information which would be lost with conventional focusing is acquired, processed, and utilized without negative effects to the observational path.