Nikon's Scanner-Nikkor ED 100mm f/2.8 lens, extracted from the Super Coolscan 8000 ED or 9000 ED and mounted via Thorlabs SM2 hardware, is one of the most capable DIY macro systems a Nikon photographer can build. The optical performance is exceptional, but the setup comes with real constraints that make it an indoor studio tool rather than a field lens. Understanding both sides is essential before committing to the build. The Scanner-Nikkor was engineered to reproduce film frames onto a CCD sensor with absolute fidelity, delivering 4000 dpi true optical resolution. It comprises 14 elements including 6 ED glass elements, corrected apochromatically from 435 nm to 852 nm, which means chromatic aberration is essentially absent across the entire visible spectrum and into near-infrared. 

Once extracted from the scanner chassis (the lens sits beneath the metal base plate, secured by a retention bar and single screw), the bare barrel carries no filter thread, no aperture ring, and no mount. Thorlabs SM2T20 threaded sleeves are epoxied over the front and rear of the barrel using stainless shim tape to build up the diameter for a zero-play fit. SM2L15 stackable extension tubes thread onto the rear sleeve to set the working magnification, and a RafCamera Nikon F-mount to SM2 adapter connects the assembly to the camera body. The whole rig is rigid and modular, swapping one extension tube adjusts the magnification without touching the lens. For the reversed orientation (~1.12–1.15x), the lens is rotated 180° in the sleeves, placing the larger element toward the sensor for maximum image quality.

Of course there are limitations in the practical use. It has a fixed aperture, there is no iris, no way to stop down, and therefore no way to increase depth of field beyond what the optics naturally provide. At 1:1 magnification, depth of field on a full-frame sensor is measured in fractions of a millimetre, which means even a slightly uneven subject surface will have portions falling out of focus. This is manageable indoors on a macro rail using focus stacking, but it makes handheld use tricky and some may say impractical for anything other than completely flat subjects. 

Equally significant is the complete absence of weather sealing or physical protection. The Thorlabs SM2 assembly is precision optical hardware and not sealed, not ruggedised, and not designed to tolerate moisture, dust, rain, or dew.