Astrophotography Nightscape Lens Rating

	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R
1	Lens	Focal Length (mm)	Relative Aperture (f/number)	Clear Aperture Diameter (mm)	Aperture Area (mm^2)	Angular Area (radians^2)	FF Suggested Exposure Time (seconds) = 500/Focal Length	APS-C Suggested Exposure Time (seconds) = 360/Focal Length	Astro Lens Score	Mirrorless and Rangefinder	Third Party DSLR	Canon	Nikon	Fuji	Micro 4/3	Sony	Lenses Ian Norman Uses Currently (Canon EOS 6D)	Lenses Ian Norman Uses (Fuji X)

2	300mm/2.8	300	2.8	107.1	9,016	0.00	2	1	64
3	200mm/2.0	200	2	100.0	7,854	0.01	3	2	188
4	200mm/2.8	200	2.8	71.4	4,007	0.01	3	2	96
5	135mm/2.0	135	2	67.5	3,578	0.02	4	3	278
6	100mm/2.0	100	2	50.0	1,963	0.04	5	4	374
7	85mm/1.2	85	1.2	70.8	3,941	0.05	6	4	1,220			Canon EF 85mm f/1.2 L
8	85mm/1.4	85	1.4	60.7	2,895	0.05	6	4	897		Rokinon 85mm f/1.4
9	85mm/1.8	85	1.8	47.2	1,751	0.05	6	4	542
10	70mm/2.8	70	2.8	25.0	491	0.08	7	5	271
11	56mm/1.2	56	1.2	46.7	1,710	0.12	9	6	1,830					Fujinon XF 56mm/1.2
12	55mm/1.4	55	1.4	39.3	1,212	0.12	9	7	1,368		Zeiss Otus 55mm f/1.4*
13	55mm/1.8	55	1.8	30.6	733	0.12	9	7	827
14	50mm/0.95	50	0.95	52.6	2,176	0.15	10	7	3,252	Leica 50mm/0.95 Noctilux M	Mitakon 50mm f/0.95
15	50mm/1.2	50	1.2	41.7	1,364	0.15	10	7	2,038			Canon EF 50mm f/1.2L
16	50mm/1.4	50	1.4	35.7	1,002	0.15	10	7	1,497		Sigma 50mm f/1.4 Art*		Nikkor 50mm f/1.4G/D				Sigma 50mm f/1.4
17	50mm/1.8	50	1.8	27.8	606	0.15	10	7	906			Canon EF 50mm f/1.8 II	Nikkor 50mm 1.8G
18	50mm/2.0	50	2	25.0	491	0.15	10	7	734
19	40mm/1.4	40	1.4	28.6	641	0.23	13	9	1,844	Voigtlander 40mm f/1.4 Nokton
20	40mm/1.7	40	1.7	23.5	435	0.23	13	9	1,251
21	40mm/2.8	40	2.8	14.3	160	0.23	13	9	461
22	35mm/1.2	35	1.2	29.2	668	0.30	14	10	2,834	Voigtlander 35mm f/1.2 II
23	35mm/1.4	35	1.4	25.0	491	0.30	14	10	2,082		Sigma 35mm/1.4 Art*			Fujinon XF 35mm/1.4				Fujinon XF 35mm/1.4
24	35mm/1.8	35	1.8	19.4	297	0.30	14	10	1,259				Nikkor 35mm f/1.8G
25	35mm/2.0	35	2	17.5	241	0.30	14	10	1,020			Canon EF 35mm f/2.0 IS
26	35mm/2.8	35	2.8	12.5	123	0.30	14	10	520
27	28mm/1.8	28	1.8	15.6	190	0.45	18	13	1,530
28	28mm/2.8	28	2.8	10.0	79	0.45	18	13	632
29	27mm/2.8	27	2.8	9.6	73	0.48	19	13	652
30	24mm/1.4	24	1.4	17.1	231	0.60	21	15	2,869		Rokinon 24mm/1.4*						Rokinon 24mm/1.4
31	24mm/1.8	24	1.8	13.3	140	0.60	21	15	1,736							Sony 24mm/1.8 - E Mount
32	24mm/2.0	24	2	12.0	113	0.60	21	15	1,406					Fuji X100s 23mm/2.0		Sony 24mm/2.0 - A Mount
33	24mm/2.8	24	2.8	8.6	58	0.60	21	15	717
34	23mm/1.4	23	1.4	16.4	212	0.64	22	16	2,967					Fujinon XF 23mm/1.4				Fujinon XF 23mm/1.4
35	23mm/2.0	23	2	11.5	104	0.64	22	16	1,454
36	22mm/2.0	22	2	11.0	95	0.70	23	16	1,505			Canon EF-M 22mm f/2.0					Canon EF-M 22mm f/2.0
37	21mm/1.4	21	1.4	15.0	177	0.76	24	17	3,180	Leica 21mm/1.4 Summilux M
38	21mm/1.8	21	1.8	11.7	107	0.76	24	17	1,924	Voigtlander 21mm f/1.8 Ultron
39	20mm/1.8	20	1.8	11.1	97	0.82	25	18	1,994
40	20mm/2.8	20	2.8	7.1	40	0.82	25	18	824							Sony 20mm/2.8 - E Mount
41	19mm/2.8	19	2.8	6.8	36	0.90	26	19	855	Sigma 19mm/2.8
42	18mm/1.8	18	1.8	10.0	79	0.98	28	20	2,146		Sigma 18-35mm/1.8*
43	18mm/2.0	18	2	9.0	64	0.98	28	20	1,738					Fujinon XF 18mm/2.0*
44	18mm/2.8	18	2.8	6.4	32	0.98	28	20	887
45	18mm/3.5	18	3.5	5.1	21	0.98	28	20	568
46	17mm f/1.8	17	1.8	9.4	70	1.08	29	21	2,228						Olympus 17mm/1.8
47	17mm/2.8	17	2.8	6.1	29	1.08	29	21	921			Canon EF-S 17-55mm/2.8
48	17mm/4.0	17	4	4.3	14	1.08	29	21	451
49	16mm/1.4	16	1.4	11.4	103	1.19	31	23	3,826					Fujinon XF 16mm/1.4
50	16mm/2.0	16	2	8.0	50	1.19	31	23	1,875		Rokinon 16mm/2.0*
51	16mm/2.8	16	2.8	5.7	26	1.19	31	23	956							Sony 16mm/2.8 - E Mount
52	16mm/3.5	16	3.5	4.6	16	1.19	31	23	612
53	15mm/2.8	15	2.8	5.4	23	1.32	33	24	994	Zeiss 15mm/2.8 ZM	Zeiss 15mm/2.8 ZE/ZF.2	Canon EF 15mm/2.8
54	15mm/3.5	15	3.5	4.3	14	1.32	33	24	636
55	14mm/2.8	14	2.8	5.0	20	1.47	36	26	1,032		Rokinon 14mm/2.8*		Nikkor 14-24mm/2.8G	Fujinon XF 14mm/2.8*			Rokinon 14mm/2.8	Fujinon XF 14mm/2.8
56	12mm/1.6	12	1.6	7.5	44	1.85	42	30	3,400						Hyperprime 12mm/1.6
57	12mm/2.0	12	2	6.0	28	1.85	42	30	2,176	Rokinon 12mm/2.0*					Olympus 12mm/2.0
58	12mm/2.8	12	2.8	4.3	14	1.85	42	30	1,110	Zeiss Touit 12mm/2.8
59	12mm/4.5	12	4.5	2.7	6	1.85	42	30	430
60	11mm/2.8	11	2.8	3.9	12	2.08	45	33	1,149		Tokina 11-16mm/2.8*
61	10mm/2.8	10	2.8	3.6	10	2.36	50	36	1,184		Rokinon 10mm/2.8
62	10mm/3.5	10	3.5	2.9	6	2.36	50	36	758
63	8mm/2.8	8	2.8	2.9	6	3.09	63	45	1,237	Rokinon 8mm f/2.8 II
64	8mm/3.5	8	3.5	2.3	4	3.09	63	45	792		Rokinon 8mm/3.5 Fisheye
65	7.5mm/3.5	7.5	3.5	2.1	4	3.31	67	48	796
66	7mm/2.8	7	2.8	2.5	5	3.55	71	51	1,246						Zuiko 7-14mm/2.8
67	Use this link to SHARE THIS DOC:			goo.gl/iU13yN							Recommended Lenses
68
69	*Highly Recommended!
70
71	Cameras and Lenses in my current kit
72	Canon 6D	Fuji X-T1	Canon EOS M	Sony a7S
73	Rokinon 14mm/2.8	Fujinon XF 14mm/2.8	Canon EF-M 22mm f/2.0	Rokinon 14mm/2.8
74	Rokinon 24mm/1.4	Fujinon XF 23mm/1.4	Rokinon 12mm/2.0	Rokinon 24mm/1.4
75	Sigma 50mm f/1.4 Art	Fujinon XF 35mm/1.4		Rokinon 35mm/1.4
76		Rokinon 12mm/2.0		Voigtlander 40mm f/1.4 Nokton
77		Rokinon 8mm f/2.8 Fisheye II
78
79	Click here for an interactive exposure calculator that will also output the astro lens score.
80
81	The "Astro Lens Score" is a number derived by multiplying the values of various lens/camera traits such as angle of view, clear aperture size and maximum exposure time without star trails. It's an arbitrary number and is only useful for comparing lenses to each other for the purposes of taking untracked astrophotos. Calculations use the sensor area of an APS-C sensor but the shutter time suggestions of a full frame lens. Lenses with higher ratings will be able to make higher signal to noise ratio photographs directly proportional to their rating numbers. In other words, a lens that scores 2000 would be capable of making a photograph with twice as much signal versus a lens with a score of 1000. This chart is purposed merely as a way to more easily compare one lens to another without having to swirl your brain around with f-stops and angles of view.
82
83	For example: A 24mm/1.4 scores about 2800 while a 24mm/2.0 scores about 1400. Based on these numbers, the f/1.4 lens should be able to collect approximately 2x more light (1 stop) than the f/2.0 lens which is what we would expect just by comparing f/numbers.
84
85	Theses scores do not account for noise and thus are NOT directly comparable across differing sensor sizes or different cameras. Differing cameras have differences in sensor quantum efficiency and these calculations only assume a single sensor size and exposure length. Keep in mind that these scores also do not take into account the other aspects of a lens's performance such as resolution, astigmatism, chromatic, coma, spherical aberration, distortion, build quality etc.
86
87	If you wish to compare lenses across different sensor sizes and account for aberration performance check out the other sheet tabs for each sensor size.
88
89	Suggested exposure times are the maximum recommeded exposure duration without star trails. The number may vary from what's shown here depending on your sensor resolution or where in the sky you are pointing your camera. This number is a good starting point, but check for star trails and adjust. You want to use the longest exposure you can with out star trails to maximize your light gathering.
90
91	Rokinon, Samyang and Bower lenses are all identical lenses made by the same Korean manufacturer: Samyang
92
93	About the product links in this doc: I use affiliate links to the respective products that I mention on this page. If you decide to buy one of these products, consider using the links in this article to support Lonely Speck. It won't cost you anything extra but Lonely Speck gets a small commission to support the website.
94
95	By Ian Norman, Creative Commons, Attribution, Sharealike, International 4.0