Mamiya Press Lens FF Equivalents

This chart converts Mamiya Press lenses to Full Frame (35mm) equivalent based on horizontal dimensions.* Most conversions are usually done using the diagonal frame size, but I personally prefer having the most accurate horizontal limits. It was created for planning viewfinder selection on Mamiya Press based mods. All dimensions are in mm.

Format W x H	Lens**	Factor***	35mm Equiv	Notes
645 56 x 41.5	50	0.64	32
645 56 x 41.5	65	0.64	42
645 56 x 41.5	75	0.64	48
645 56 x 41.5	80	0.64	51
645 56 x 41.5	90	0.64	58
645 56 x 41.5	100	0.64	64
645 56 x 41.5	127	0.64	81
645 56 x 41.5	150	0.64	96
645 56 x 41.5	250	0.64	160
66 56 x 56	50	0.64	32	21mm masked
66 56 x 56	65	0.64	42	28mm masked
66 56 x 56	75	0.64	48	32mm masked
66 56 x 56	80	0.64	51	34mm masked
66 56 x 56	90	0.64	58	39mm masked
66 56 x 56	100	0.64	64	43mm masked
66 56 x 56	127	0.64	82	54mm masked
66 56 x 56	150	0.64	96	64mm masked
66 56 x 56	250	0.64	161	107mm masked
67 70 x 56	50	0.51	26
67 70 x 56	65	0.51	33
67 70 x 56	75	0.51	39
67 70 x 56	80	0.51	41
67 70 x 56	90	0.51	46
67 70 x 56	100	0.51	51
67 70 x 56	127	0.51	65
67 70 x 56	150	0.51	77
67 70 x 56	250	0.51	129
68 77 x 56	50	0.47	23
68 77 x 56	65	0.47	30
68 77 x 56	75	0.47	35
68 77 x 56	80	0.47	37
68 77 x 56	90	0.47	42
68 77 x 56	100	0.47	47
68 77 x 56	127	0.47	59
68 77 x 56	150	0.47	70
68 77 x 56	250	0.47	117
69 84 x 56 3:2	50	0.43	21
69 84 x 56 3:2	65	0.43	28
69 84 x 56 3:2	75	0.43	28
69 84 x 56 3:2	80	0.43	34
69 84 x 56 3:2	90	0.43	39
69 84 x 56 3:2	100	0.43	43
69 84 x 56 3:2	127	0.43	54
69 84 x 56 3:2	150	0.43	64
69 84 x 56 3:2	250	0.43	107
Instax Mini 62 x 46	50	0.58	29	Rotate 90°
Instax Mini 62 x 46	65	0.58	38	Rotate 90°
Instax Mini 62 x 46	75	0.58	44	Rotate 90°
Instax Mini 62 x 46	80	0.58	46	Rotate 90°
Instax Mini 62 x 46	90	0.58	52	Rotate 90°
Instax Mini 62 x 46	100	0.58	58	Rotate 90°
Instax Mini 62 x 46	127	0.58	74	Rotate 90°
Instax Mini 62 x 46	150	0.58	87	Rotate 90°
Instax Mini 62 x 46	250	0.58	145	Rotate 90°
PO600/SX-70 77 x 79	50	0.46	23	15mm masked
PO600/SX-70 77 x 79	65	0.46	30	20mm masked
PO600/SX-70 77 x 79	75	0.46	34	22mm masked
PO600/SX-70 77 x 79	80	0.46	36	24mm masked
PO600/SX-70 77 x 79	90	0.46	41	27mm masked
PO600/SX-70 77 x 79	100	0.46	46	30mm masked
PO600/SX-70 77 x 79	127	0.46	58	39mm masked
PO600/SX-70 77 x 79	150	0.46	68	46mm masked
PO600/SX-70 77 x 79	250	0.46	114	76mm masked
Instax Square 62 x 62	50	0.58	29	19mm masked
Instax Square 62 x 62	65	0.58	38	25mm masked
Instax Square 62 x 62	75	0.58	44	29mm masked
Instax Square 62 x 62	80	0.58	46	31mm masked
Instax Square 62 x 62	90	0.58	52	35mm masked
Instax Square 62 x 62	100	0.58	58	39mm masked
Instax Square 62 x 62	127	0.58	74	49mm masked
Instax Square 62 x 62	150	0.58	87	58mm masked
Instax Square 62 x 62	250	0.58	145	97mm masked
Instax Wide 99 x 62	50	0.36	18
Instax Wide 99 x 62	65	0.36	24
Instax Wide 99 x 62	75	0.36	27
Instax Wide 99 x 62	80	0.36	29
Instax Wide 99 x 62	90	0.36	33
Instax Wide 99 x 62	100	0.36	36
Instax Wide 99 x 62	127	0.36	46
Instax Wide 99 x 62	150	0.36	55
Instax Wide 99 x 62	250	0.36	91

* For square formats, height will be the same as width, masked FF equivalents provided in Notes column. For Instax Mini, rotate 90° for portrait orientation.
** 80mm refers to a custom lens, if using any of my TLR adapters.
*** 35mm dimension used is 36mm x 24mm (3:2).