Having the possibility to search photo based on Camera Body or Lens model would be great. Telephoto lens may have similar ‘focal length’ as other telephoto or fixed lens. It then become difficult to identify photo taken with specific lens when looking for aperture or focal number.
Same for the camera body. Some are using different camera body for shooting. It would be good to have the possibility to search photo for specific camera body.
Finally, making a search on any EXIF, IPTC data (GPS, Flash fired, Exposure Bias, … ) data would be even better and would grant more flexibility in the search module.