The field of view will vary depending on the lens used at the end of the borescope. Most of the Teslong borescope lenses have a 70-degree field of view. Articulated borescopes increase that field of view and dual-lens borescopes double that with 2 x 70-degree lenses. Some borescopes also offer different fields of view for different applications – you may only need a 10-degree field of view to identify small problems in a rifle, but need a 100-degree field of view to identify plumbing problems.