I have now managed to collect the Cosina Voigtlander (CV) Leica Thread Mount (LTM) lenses from 15mm to 50mm. The only ones I'm missing are the 12/5.6 and the 25/4. Since I have the 21 and 28 the 25 is a bit redundant so I probably won't get one. Here's some shots with the 5N/CV21. CornerFix applied.