The most common question asked on Lonely Speck answered for Canon shooters!
What is the best lens for astrophotography? The one that collects the most light.
Below is a list of the highest scoring lenses for untracked nightscape photography and astrophotography. The score is a direct representation of light gathering capabilities based on the formula:
Score = (aperture area) × (angular area) × (suggested shutter speed)
Where the shutter speed is the longest suggested shutter speed in seconds based on the “500 Rule” (500/focal length). Aperture area is the surface area calculation of the clear aperture of the lens and the angular area is the angular field of view in square radians. This score is a mathematical calculation based purely on some simple physics. It doesn’t account for other considerations like the lens’s build quality or optical aberrations but it’s a good gauge of overall light gathering capability. You can also see the complete list of scores here, complete with calculations and further explanation.
All of the lenses listed here are my personal suggestions for photographers looking to get the absolute best astrophotography results with their camera. If using the given camera mount, these are the lenses that I would use. Most of these lenses are manual focus lenses by Rokinon which also tend to be much more affordable than their autofocus Canon counterparts. Additionally, most of the Rokinon lenses are sharper and tend to exhibit less coma aberration than their Canon counterparts. If you’re willing to learn how to use manual focus, Rokinon lenses are spectacular performers.
If you would like to know more about the thoughts that went into creating this list, please read my article on how to pick a lens for Milky Way photography.
EF Mount (Full Frame and APS-C)
- The best night photography and astrophotography lens you can buy. Excellently sharp, especially when stopped to f/2. Manual focus.
- My full review of the Rokinon 24mm f/1.4
- Score: 2869
- This is my go-to lens for astrophotography on a full-frame DSLR. It’s fast, wide and shows very little aberration problems. Still my personal favorite for Canon full frame DSLRs like the 6D, 5D Mark III and 5DS/R cameras.
- Sample from the Rokinon 24mm f/1.4:
- Standard wide angle for tighter landscapes or stitching multiple exposures into larger panoramas. Rokinon is manual focus, Sigma is autofocus.
- Score: 2084
- Essential ultra-wide angle for large sweeping landscapes. Manual focus. One of the most affordable full frame nightscape lenses.
- My full review of the Rokinon 14mm f/2.8
- Score: 1032
- Sample image from the Rokinon 14mm f/2.8:
EF-S Mount (APS-C Only)
- The best combination of wide angle and large aperture. Manual focus.
- Score: 1875
- APS-C alternative to the Rokinon 14mm/2.8. Excellent for ultra-wide angle landscapes. Manual focus.
- Score: 1184
- Covers the same range as the two previous lenses combined. Excellent super wide angle zoom with autofocus.
- Score: 1149 (at 11mm)
EF-M Mount (APS-C Mirrorless)
- Best lens for astrophotography on a mirrorless system. Nice and compact, best combination of super-wide field of view and large aperture.
- Score: 2176
- Sample image from the Rokinon 12mm f/2:
- Surprisingly sharp and extremely compact lens. Also very cheap. Standard wide angle view makes it good for panorama stitches.
- Score: 1505
- Sample image from the Canon EF-M 22mm f/2 STM: