Pros & Cons
PROs
Real f/1.8 aperture: It is extremely bright for an ultra wide angle, which makes it unbeatable in astrophotography and for separating the subject from the background. Informative LCD Screen: A rare innovation at this price; Allows you to see the focus and aperture distance without looking at the camera screen, ideal for night shots. Optimized for Video: The STM motor is silent, has almost zero focus breathing and the aperture ring is "de-clickable" (you can unclick it). Build Quality: Includes weather sealing, customizable Fn buttons, and USB-C port for firmware updates. Standard Filter Thread: Despite being a very bright 16mm, it allows you to use common 77mm filters without the need for cumbersome adapters.
CONs
Size and Weight: At 550g and 10cm long, it is a powerful target. On very small bodies like your Lumix S9, the set will feel "headed" (unbalanced forward). Edge Distortion: As is natural with a 16mm, there is noticeable perspective distortion in the corners, which requires correction if you do highly technical architectural photography. Without Optical Stabilization (OIS): It does not have an internal stabilizer. Although cameras like the S9 have a great IBIS, in freehand video the lack of optical help is noticeable in such wide-angle focal lengths. Vignetting at f/1.8: At its maximum aperture it presents a noticeable darkening in the corners that, although it is easily corrected in editing, is something to take into account. Bulky Lens Hood: The included petal lens hood is quite large, which adds extra volume when you want to go for a minimalist set-up.
