2oz HELIMAX-XP Camera Telescope Optical Instrument Focusing Helicoid Grease PTFE

New Handmade Plastic PVC - Focusing Card for Pentax 17 Camera (2 Pack)

M42 M52 M58 M62 to M65 Thread Ring Adapter for Lens Focusing Helicoids Tube 65mm

Olympus Focusing Screen 1-4 matte focusing screen for OM film cameras

M42 M52 M58 M62 to M65 Thread Ring Adapter for Lens Focusing Helicoids Tube 65mm

10pcs 19.5/23mm Optical Plastic Lens LED Plano-convex DIY Focusing Condenser

New Handmade Plastic PVC - Focusing Card for Pentax 17 Camera (2 Pack) White

Optical Glass Optional LED Plano-convex Lens DIY Focusing Condenser Lens 28-40mm