The used Pentax SMC FA 645 400mm f/5.6 ED IF for Medium Format is a legacy telephoto prime lens that’s compatible with the Pentax 645Z. Key features include:
Excellent for wildlife photography
Clutch design for fast autofocus/manual-focus switching
Advanced optical design for high-quality images
Internal-focusing system
Telephoto Prime. With a focal length equivalent to 315mm after sensor crop factor, the 400mm f/5.6 is a high-quality prime that reaches out to the super telephoto focal range. Its long reach makes it ideal for wildlife photography, and the adventurous might stretch it for sports photography use.
Autofocus/Manual-Focus Clutch. The 400mm f/5.6 uses a clutch design to switch between AF and MF, giving you fast access to make minute manual-focusing tweaks.
Internal Focusing. The internal-focus design means the focusing group is much smaller and easier to move. Not only does this enable the lens barrel to stay in place while focusing, but it also increases focusing speed.
Please Note. This is a legacy lens that was originally designed for medium-format film cameras. We’ve noticed that it tends to slightly front- or back-focus, so you’ll want to make sure you microfocus adjust before you start shooting.
