Ricoh 55mm f2.2 Riconar projector or use the high resolution

or use the high resolution eye-level viewfinder

But there's no optical rangefinder patch for manual focusing like there might be in a Leica

with a pair of Rolleinar 2 diopters and a Rolleiparkeil parallax correction lens

The Voigtlander Ultron 40mm f2 SLII S is a lovely manual focus lens for Nikon F mount SLR cameras

this one is such a viewfinder and should fit the bill

Ricoh 55mm f2.2 Riconar projector or use the high resolutionHey, u ever see a cell focusing SLR lens? Now you have. I'm assuming that this was the absolute cheapest lens that it was possible to make, dispensing with the multiple helicoids of a unit focusing lens for a single moving front element that kind of partially unscrews to focus. Image quality is wonderfully soft wide open, especially at closer range. Please do not buy this as a standard 50mm lens and expect it to be "good," because it is not "good." It