Kowa 50-80mm 63/4.5

Japanese enlarger lens with strong warm cast/ Tested here at 64mm.

Weight	226 g
Dimensions	63 mm
Focal Length (mm)	63
Max Aperture (f)	4.5
Min Aperture (f)	32
Aperture Blades	8 (Straight)
Elements	11
Sharp (Far)	78.3%
Rear Mount	M39
Front Thread	40×0.75mm
Flange-Focal Distance (mm @ ∞)	63
RF/L Extension (mm)	43
Production	1979-
Serial Numbers	110744
Bokeh Character	Good stars from f5.6. Clean, very mild bubble. Some LOCA.
Contrast	Medium/High
Colour	6
Focus Shift	None
Flare	6.5
Stars	7.5