Optic image-guidance systems enable minimally invasive (MIS) approaches in surgery. However, available MIS-techniques limits both ergonomics and field of view (FoV), which can be detrimental for anatomical awareness and safe manipulation with tissues. Contemporary navigation techniques (i.e. neuronavigation) support spatial awareness during surgery. However, these techniques require time-consuming instrumentation and lack real-time precision needed in soft-tissue surgery. In this work, we utilize operative microscopes FoV as an unobtrusive source to support MIS-navigation with micro-instrument tracking. The FoV instrument tracking has been investigated in laparoscopy, however, high magnification, selection of instruments and bimanually variant characteristics of microneurosurgery make the current computational approaches challenging to adopt. In this work, we investigate potentials of spectral