Hello johnnokomis,
You can use the following script (adds a custom menu item for faster access) that sorts the cameras in the Photos pane according to the number of marker projections placed, cameras with no projections will be filtered out:
import Metashape, operator
def filter_photos_by_projections():
chunk = Metashape.app.document.chunk
cam_proj = {}
for marker in chunk.markers:
for camera in marker.projections.keys():
if not (camera in cam_proj.keys()):
cam_proj[camera] = 1
else:
cam_proj[camera] += 1
sorted_cams = sorted(cam_proj.items(), key=operator.itemgetter(1))
sorted_cams = [[x[0]] for x in list(sorted_cams)]
sorted_cams.reverse()
Metashape.app.photos_pane.setFilter(sorted_cams)
Metashape.app.addMenuItem("Custom menu/Filter Photos by Marker Projections", filter_photos_by_projections)