Secondary lens
（重定向自Accessory lens）
![A fisheye secondary lens that attaches to a phone camera using a magnetic ring, with an example image using the lens](/Images/godic/202412/19/Fisheye_phone_lens_collage_with_example_image4155.jpg")
In photography, a secondary lens is a lens designed to be used in conjunction with another lens, called the primary lens.
A secondary lens may be designed to be used either in front of the primary lens, between it and the subject, or behind the primary lens, between it and the film.