Best Full Frame Sony e-Mount Lenses for
Milky Way AstroPhotography
Over a decade ago, Sony ignited the mirrorless revolution with the groundbreaking Alpha 7 camera. Since then they’ve been pumping out E-mount lenses of incredible quality and third-party manufacturers have been scrambling to fill the gaps and provide alternatives for all budgets. So with such an overwhelming amount of choice, how do you choose the right lens for capturing the Milky Way with your Sony E-mount camera?
This article delves into the key factors to consider when selecting a lens for landscape astrophotography, explores the pros and cons of prime and zoom lenses, and summarises all the best options for capturing the most captivating photos of the Milky Way.
What makes a good milky way lens?
Focal length
Wide angle lenses allow you to capture the grandiose Milky Way whilst still including some interesting foreground. For beginners I recommend 14 to 20mm as this field of view makes it easy to capture wide scenes in a single exposure and still have some breathing room for cropping if need be. My personal favourite focal length is 24mm but this is where you start to rely more on panoramas to capture the entire scene you’re after. As you increase the focal length further astrophotography becomes more difficult as these lenses require shorter shutter speeds in order not to see star trailing and so beyond 28mm you become more dependant on star trackers. Long story short, if you’re a beginner start with 14-20mm and work your way to longer focal lengths as your skills improve.
Maximum aperture
Aperture is the diameter of the opening inside the lens that lets lights through. It’s denoted by f-stops (the ratio of aperture over lens focal length) and a lower f-stop equates to a wider aperture. The wider the aperture, the more light that is allowed to pass through onto your sensor and the brighter and less noisy your image will be. So you could say the wider the aperture the better for astrophotography, but there are some caveats to this you need to be aware of which we’ll discuss in the next point. Personally, I would recommend a lens that opens up to at least f/2.8. This is usually enough to get good detail in the Milky Way without having too much noise in your images.
Lens Aberrations
Lens aberrations are imperfections in the way lens optics focus light. They can have a negative impact on many things including sharpness, colour, distortion, and focus, but are particularly noticeable in the stars of an image. Coma makes the stars in the corner of the frame look like comets, astigmatism adds wings and/or tails to the stars making them look like birds and chromatic aberration can add coloured fringes to stars and sharp edges. On the other hand, spherical aberration can add a glow to bright stars which sometimes produces a desirable effect.
Lens aberrations will be at their worst at the widest aperture settings and so stopping down typically improves image quality. It’s also worth noting that even the most expensive lenses will suffer from lens aberrations and price isn’t always a determining factor in how good a lens is for capturing the night sky.
Prime vs Zoom
Zoom lenses offer the versatility of multiple focal lengths in one lens but prime lenses are able to provide a wider maximum aperture such as f/1.4 or f/1.8 and are able to collect more light in a single exposure. You also have the freedom to stop down the aperture with prime lenses to improve aberrations and vignetting. This reduction in vignetting will often mean that a prime lens stopped down to f/2.8 will collect more light in a single exposure than an f/2.8 zoom lens. So prime lenses typically have the advantage in performance and light transmission, but prime zooms offer a more versatile, lightweight and more compact solution.
I actually made an entire video discussing the pros and cons of primes versus zooms but in summary:
Prime Lenses |
Zoom Lenses |
|---|---|
| ✅ Wider maximum apertures | ✅ Versatility of zoom |
| ✅ Often sharper | ✅ Lighter than multiple primes |
| ✅ Lower vignetting | ✅ Cheaper than multiple primes |
| ✅ Better light transmission (and less noise) | ✅ Takes up less bag space |
| ✅ Freedom to stop down aperture to improve aberrations | ❌ Limited maximum aperture |
| ❌ No Zoom | ❌ Heavy vignetting |
| ❌ Changing lenses in the field risks dust on sensor | ❌ Lower light transmission (more noise) |
Best e-Mount prime lenses
Sony 14mm f/1.8 GM
Price (New): £1399
Weight: 460g / 16.2 oz
Size (DxL): 83 x 104 mm
Filter Thread: Third-party options for front or rear-mount
How Sony managed to make such a fast wide-angle lens this small and lightweight is beyond me. One of my personal favourite lenses and performance all-round is excellent. I love using this lens for getting up close and personal to foreground subjects and focus stacking. Its only real competitor is the Sigma lens discussed next.
Sigma 14mm F/1.4 DG DN Art
Price (New): £1399
Weight: 1,170g / 41.3oz
Size (DxL): 101 x 152 mm
Filter Thread: Built-in rear mount system
Announced in June 2023, the Sony 14mm GM finally faced some competition. Its large bulbous front element has helped to minimise vignetting but the wider aperture of f/1.4 has resulted in a much bigger and heavier design compared to Sony’s. So much so that it even comes with its own lens collar and mounting foot, something I don’t think I’ve ever seen in a wide angle lens before. It also comes with a handy focus lock switch. It comes in at the same price as the Sony but edges it in performance of vignetting and aberrations at the cost of carrying something much bigger and heavier. If you do a lot of aurora photography I’d say it’s worth it.
Note: Not to be confused with the Sigma 14mm f/1.8 DG HSM Art lens for Sony E-mount. This was released back in 2017 and is an adapted version of their older design for DSLR cameras. This lens does not perform as well and should no longer be considered given the lenses that have been released since.
Samyang 14mm 2.8 IF ED UMC
Price (New): £365
Weight: 550g / 19.5oz
Size (DxL): 87 x 102mm
Filter Thread: N/A
This lens deserves a spot in the astrophotography hall-of-fame! It’s been around for over 10 years and provides a decent budget option with good coma correction. It has heavy distortion which can be handled in post-production and the vignetting is a little strong but otherwise for this price you can’t argue. Sample variation is rife amongst these lenses, some can’t focus to infinity and others are decentred, so be sure to order from a reputable source where you can return or exchange if you receive a poor copy.
A new MK2 version was released in 2020 with the same optical design but an added focus lock and aperture de-click feature.
Samyang AF 14mm f/2.8 FE
Price (New): £369
Weight: 500g / 17.6oz
Size (DxL): 86 x 98mm
Filter Thread: N/A
Has slightly less distortion than the MF versions but otherwise worse in terms of coma and astigmatism. If you’re not desperate for auto-focus, the MF options are better for astrophotography.
Laowa 15mm f/2 Zero-D
Price (New): £769
Weight: 500g / 17.6oz
Size (DxL): 77 x 82mm
Filter Thread: 72mm
This compact lens is priced between the cheap MF Samyang offerings and the expensive Sony and Sigma 14mm options. In comparison to the Samyang MF 14mm it has better light transmission (brighter, less noisy images) but is worse in terms of coma and astigmatism, even when stopped down to f/2.8. Not to say that it performs awfully, but expect some winged stars in the extreme corners. It also doesn’t have electronic communication with the camera so there is no aperture data in the EXIF. Perhaps a bit expensive when bought new but can sometimes be found much cheaper used. For some, the ability to take front-mounted 72mm filters could be the deciding factor to choose this lens.