This professional trinocular compound microscope provides both darkfield and brightfield features. It boasts three unique features no other microscope dealer can claim, designed for professional applications in clinical offices and research laboratories. Different from most other microscopes on the market, the T490B is remarkable because it features 1) simultaneous viewing through the photo port and eyepieces, 2) an adjustable parfocal trinocular port, and 3) a detachable C-Mount located on the 23mm photo port. T490Bs adjustable trinocular port creates a parfocal optical system by allowing the image system attached to the photo port and the image in the eyepieces to be in focus at the same time. Traditional microscopes on the market allow you to see through either the trinocular port or eyepieces, forcing you to switch between the port and eyepieces. Because their trinocular port is not designed to be par-focal with the microscope optical system, you have to conduct re-focusing after each "switch". The T490B, however, has simultaneous viewing and parfocal trinocular port so that these "switch" and "re-focusing" are no longer necessary. Especially handy for teaching demonstrations, clinical examinations and laboratory applications, these features allow your students or colleagues to view crystal clear images simultaneously while you work through the eyepieces. In addition, the T490Bs industry standard 23mm photo port can be converted into a C-Mount port by putting on the free C-mount adapter included, allowing you to attach most of microscope digital cameras and video systems on the market. This versatile microscope is also capable of being upgraded with various accessories and attachments for additional functions. The T490B also includes a 30° inclined 360° swiveling compensation-free trinocular head, a 3-D mechanical stage, and an intensity-variable halogen illumination system. This microscope is made by the same technicians and on the same production