BUHL 5-ELEMENTS FLAT FIELD PROJECTION NON-SYMMETRICAL LENS.
MEASURED & CALCULATED by SELLER, SOLD AS DESCRIBED. AS CALCULATED.
Mounting ring for M65 adapter is 54mm as pictured / mounting ring not included. /

WORK for FULL FRAME, HALF-FTAME, Super35, & MEDIUM FORMAT /REVERSED SETTING/.

VG+ BUHL Optical USA/ factory unmarked/ 48mm 
 
F1.++ FAST 5-element 48mm GEOMETRICAL CALCULATED//70mm ANGLE COVERAGE.

METTERED THROUGH THE LENS ACTUAL F#n COULD BE DIFFERENT from GEOMETRICAL VALUE CALCULATION. 

REVERSED SETTING WILL MAKE IT 80mm F1.7(geometrical) MEDIUM FORMAT LENS.
SAME MOUNTING RING 54mm RING, SETTING INWARDS reversed.

 
PROJECTION FLAT FIELD /soft, no distortions/ LENS.

CLEAN, CLEAR GLASS HAS NO SCRATCHES, NO FUNGUS, NO DUST.

Perfect for making CLASSIC SOFT RETRO portraiture, particularly B&W.

REAR BARREL FITTING DIAMETER D54mm. REAR ELEMENT D39mm, FRONT D48mm. 
GEOMETRICALLY CALCULATED 48mm:48mm = f1.
60mm LONG. 
BY VIEWING COVERAGE MOUNTED ON SONY A7R4 IT APPEARS LIKE NEAR 70mm f1.7.

test PHOTO with full frame SONY a7r4.
NON-PROCESSED & TUNED in WINDOWS PHOTO VIEWER JPEG PICTURES PLACED.

I have a lot of BUHL Optical USA /factory non-marked/ lenses; they're just amazing!

/Look at my listing/ -
Sharp F2 FAST 180mm UHD PPROJECTOR LARGE MEDIUM+4X5"5x7"LENS Camera TEST PERFECT