ความหมายของ DOV และ FOV

ในการเลือกบอร์สโคป จำเป็นที่จะต้องทราบความหมายของ DOV และ FOV เพื่อช่วยในการเลือก Borescope ที่เหมาะสมกับการนำไปใช้งาน

DOV = Direction of View หรือทิศทางการมองเห็น

Take a longitudinal axis through the center of the body of a rigid borescope, or the tip of a flexible. The direction-of-view is the angle from that axis of the center of the field-of-view.
Look at your particular application, noting the point of borescope entry and the area to be examined. If the subject is straight ahead of a convenient entry hole a 0° direction-of-view might be best. If the subject is very close to the entry port, like engine valves near a spark plug hole, a backward-looking 120° borescope might be best. When examining a bore, like a rifle barrel, a 90° Mirror Tube will be perfect.

FOV = Field of View หรือพื้นที่ของการมองเห็น

Field-of-view may be very wide, wide, medium, or narrow. Think of it as a cone coming from the borescope tip, so that anything within the cone is visible. The field-of-view of the Hawkeye Slim borescope is approximately 37°.
Field-of-View should be dictated by the distance from the distal end of the borescope to the subject, for your application. The wider the field the lower the magnification, and vice versa. If you have plenty of space to move inside the cavity, but want to see both detailed close-ups and big picture views you might choose a 67° moderate wide angle. If the space is more confined but you still need to see most of it at one time, try a 90° extreme wide angle. On the other hand, if you can't get close enough to show the detail you need, a 30° telephoto might be required.