Industar 50mm f3.5 Lens Nikon Infinity + Macro Modification

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This modification enables the cost-effective Russian Industar 50mm lens to be focused at infinity with Nikon cameras using a Nikon adapter, specifically the type without the correction lens used in the Hubble telescope. It also allows for some level of macro focus. The process is relatively straightforward; however, after this modification, the lens will detach from its focus helicoil after approximately two rotations when employed in macro mode, so handle it with care to avoid dropping the lens. To make the modification: 1) Remove the front focus ring by unscrewing three screws and align the slot on the inner focus ring with the focus end stop peg. 2) Remove this peg and completely unscrew the focus helicoil; then, remove the two focus end stop pegs. 3) Attach the 3D printed 'C' ring, which serves as a safety focus stop to prevent the lens from being screwed too far into the camera body. 4) Reassemble the lens onto the camera body and attach the 3D front ring for a snug fit. The iris markings were duplicated from the original focus ring by photocopying them and sticking them on with double-sided tape, while covering the text with clear packing tape for protection.