Sawn-Off 25mm f/1.4 C-Mount CCTV Lens for Micro Four Thirds
2011
Industrial 25mm f/1.4 C-mount security camera lenses are designed for tiny 1/3" CCTV sensors and lack the flange focal distance to focus to infinity on Micro Four Thirds mirrorless bodies.
Using a junior hand hacksaw, coarse sandpaper, and two-part epoxy, Dylan filed down the rear aluminum threaded collar by 3.2mm, bringing the rear optic element close enough to the Panasonic Lumix GF1 sensor to achieve true infinity focus. The resulting lens delivers razor-sharp centre sharpness with legendary swirly peripheral bokeh and vivid vignetting.
01. Stock £15 industrial 25mm f/1.4 CCTV lens before modification
02. Hand-sawing 3.2mm off rear threaded collar with junior hacksaw
03. Wet-sanding collar face flat on glass plate to ensure parallel alignment
04. Epoxied to m43 body cap with infinity focus achieved