Close Up Exposure / Magnification Tables

These Close Up Exposure / Magnification Tables are for lenses of focal lengths including 50mm, 80mm, 100mm and 135mm. The tables show the exposure factor which needs to be multiplied by the metered exposure to determine the exposure increase when using non-TTL metering cameras or flash. These tables can be used for photographs taken using bellows or extension tubes.

For lenses of 50mm focal length

Extension increase (z)	Subject distance (a)	Image distance(a')	Total distance (a+a'=e)	Scale of reproduction (b')	Subject area (f/g)	Exposure factor (v)
mm	mm	mm	mm	mm	mm	mm
0	inf	50	inf	different	variable	1.2
5	550	55	605	0.1	240x360	1.4
10	300	60	360	0.2	120x180	1.6
15	217	65	282	0.3	80x120	1.7
20	175	70	245	0.4	60x90	2.0
25	150	75	225	0.5	48x72	2.3
30	133	80	213	0.6	40x60	2.6
35	121	85	206	0.7	34x51	2.9
40	113	90	203	0.8	30x45	3.2
45	106	95	201	0.9	27x40	3.6
50	100	100	200	1.0	24x36	4.0
60	92	110	202	1.2	20x30	4.8
70	86	120	206	1.4	17x26	5.8
80	81	130	211	1.6	15x23	6.8
90	78	140	218	1.8	13x20	7.8
100	75	150	225	2.0	12x18	9.0
110	73	160	233	2.2	11x16	10.2
120	71	170	241	2.4	10x15	11.6
130	69	180	249	2.6	9x14	13.0
140	68	190	258	2.8	9x13	14.4
150	67	200	267	3.0	8x12	16.0
160	66	210	276	3.2	8x11	17.6
170	65	220	285	3.4	8x11	19.4
180	64	230	294	3.6	7x10	21.2
190	63	240	303	3.8	6x9	23.0
200	63	250	313	4.0	6x9	25.0
210	62	260	322	4.2	6x9	27.0
220	61	270	331	4.4	5x8	29.0

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For lenses of 80mm focal length

Extension increase (z)	Subject distance (a)	Image distance(a')	Total distance (a+a'=e)	Scale of reproduction (b')	Subject area (f/g)	Exposure factor (v)
mm	mm	mm	mm	mm	mm	mm
0	inf	80	inf	different	variable	1.0
5	1360	85	1445	00.6	392x576	1.1
10	720	90	810	0.12	192x288	1.3
15	507	95	602	0.19	127x192	1.4
20	400	100	500	0.25	96x144	1.6
25	336	105	441	0.31	77x115	1.7
30	294	110	404	0.38	64x96	1.9
35	263	115	378	0.44	55x82	2.1
40	240	120	360	0.50	48x72	2.3
45	222	125	347	0.56	43x64	2.5
50	208	130	338	0.62	38x58	2.7
60	186	140	326	0.75	32x48	3.1
70	171	150	321	0.88	27x41	3.5
80	160	160	320	1.00	24x36	4.0
90	151	170	321	1.12	21x32	4.5
100	144	180	324	1.25	19x29	5.0
110	138	190	328	1.38	17x26	5.6
120	133	200	333	1.50	16x24	6.2
130	129	210	339	1.63	15x22	6.9
140	126	220	346	1.75	14x21	7.6
150	123	230	353	1.87	13x19	8.3
160	120	240	360	2.00	12x18	9.0
170	118	250	368	2.12	11x17	9.8
180	116	260	376	2.25	11x16	10.6
190	114	270	384	2.38	10x15	11.4
200	112	280	392	2.50	10x14	12.3
210	110	290	400	2.63	9x14	13.2
220	109	300	409	2.75	9x13	14.1

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For lenses of 100mm focal length

Extension increase (z)	Subject distance (a)	Image distance(a')	Total distance (a+a'=e)	Scale of reproduction (b')	Subject area (f/g)	Exposure factor (v)
mm	mm	mm	mm	mm	mm	mm
0	inf	100	inf	different	variable	1.0
5	2100	105	2205	0.05	480x720	1.1
10	1100	110	1210	0.10	240x360	1.2
15	767	115	882	0.15	160x240	1.3
20	600	120	720	0.20	120x180	1.4
25	500	125	625	0.25	96x144	1.6
30	433	130	563	0.30	80x120	1.7
35	386	135	521	0.35	69x103	1.8
40	350	140	490	0.40	60x90	2.0
45	322	145	467	0.45	53x80	2.1
50	300	150	450	0.50	48x72	2.3
60	267	160	427	0.60	40x60	2.6
70	243	170	413	0.70	34x51	2.9
80	225	180	405	0.80	30x45	3.2
90	211	190	401	0.90	27x40	3.6
100	200	200	400	1.00	24x36	4.0
110	191	210	401	1.10	22x33	4.4
120	183	220	403	1.20	20x30	4.8
130	177	230	407	1.30	18x27	5.3
140	171	240	411	1.40	17x26	5.8
150	167	250	417	1.50	16x24	6.3
160	163	260	423	1.60	15x23	6.8
170	159	270	429	1.70	14x21	7.3
180	156	280	436	1.80	13x20	7.8
190	153	290	443	1.90	13x19	8.4
200	150	300	450	2.00	12x18	9.0
210	148	310	458	2.10	11x17	9.6
220	145	320	465	2.20	11x16	10.2

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For lenses of 135mm focal length

Extension increase (z)	Subject distance (a)	Image distance(a')	Total distance (a+a'=e)	Scale of reproduction (b')	Subject area (f/g)	Exposure factor (v)
mm	mm	mm	mm	mm	mm	mm
0	inf	135	inf	different	variable	1.0
5	3780	140	3920	0.04	600x900	1.1
10	1958	145	2103	0.07	343x514	1.2
15	1350	150	1500	0.11	218x327	1.2
20	1046	155	1201	0.15	160x240	1.3
25	864	160	1024	0.19	126x289	1.4
30	742	165	908	0.22	109x164	1.5
35	656	170	826	0.26	92x138	1.6
40	591	175	766	0.30	80x120	1.7
45	540	180	720	0.33	73x109	1.8
50	500	185	685	0.37	65x97	1.9
60	439	195	634	0.44	55x82	2.1
70	395	205	600	0.52	46x69	2.3
80	363	215	578	0.59	41x61	2.5
90	338	225	563	0.67	36x54	2.8
100	317	235	552	0.74	32x49	3.0
110	301	245	546	0.82	29x44	3.3
120	287	255	542	0.89	27x40	3.6
130	275	265	540	0.96	25x38	3.9
140	265	275	540	1.04	23x35	4.2
150	257	285	542	1.11	21x32	4.5
160	249	295	544	1.18	20x30	4.8
170	242	305	547	1.26	19x29	5.1
180	236	315	551	1.33	18x27	5.4
190	231	325	556	1.41	17x26	5.8
200	226	335	561	1.48	16x25	6.2
210	222	345	567	1.56	15x23	6.5
220	218	355	573	1.63	15x22	6.9

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