Sony FE 14mm f/1.8 GM Review

Focusing Characteristics

The Sony 14mm f/1.8 GM autofocuses quickly and almost silently. The only meaningful sound is when the aperture blades close as you focus. Accuracy is excellent, even in a lab environment which magnifies small focusing errors.

Because of the f/1.8 maximum aperture, this lens focuses in dark conditions without any issue. At times, I was even able to autofocus on the stars – although careful manual focus was more reliable. Focus speed remained nice and fast even in dim conditions.

The close focusing distance of the Sony FE 14mm f/1.8 GM is nothing to write home about. With a maximum magnification of just 0.1× (also written as 1:10), you certainly won’t be doing any wide-angle macro photography with this lens. It’s workable for basic close-ups, but that’s a low bar.

Distortion

The Sony 14mm f/1.8 GM has moderate levels of distortion – not surprising for a 14mm lens, even a prime. In the lab, I measure this lens as having -2.02% barrel distortion. You can see a simulation of that below:

Almost every 14mm lens on the market has some barrel distortion. The roughly 2% distortion seen here is low enough that you can correct it in post-processing pretty easily, without stretching the corners back into place too much. That said, it’s still visible if there are a lot of straight lines in your photos. Architectural photographers will want to correct it more often than not.

Vignetting

In uncorrected images, the Sony 14mm f/1.8 GM has moderately high vignetting that never fully goes away, although this is not surprising for such a wide lens. Here’s a full chart of vignetting levels:

The maximum of 2.21 stops occurs at f/1.8 and infinity focus. Stopping down to f/2.8 results in 1.5 stops of vignetting at infinity focus. It doesn’t improve much as you stop down further.

We’ve seen worse vignetting than this before. Note, too, that this is measured before correcting the 2% barrel distortion; things get a little better when you crop out the far corners. Still, it’s high enough that you may need corrections even at landscape photography apertures like f/11.

Chromatic Aberration

There is a relatively small amount of chromatic aberration on the Sony 14mm f/1.8 GM. Here’s the chart:

Anything under about one pixel is almost impossible to notice in real-world images, even with chromatic aberration corrections turned off. The Sony 14mm f/1.8 GM hovers just above that mark. Generally speaking, you won’t need to correct for lateral CA most of the time on this lens. When you do, there shouldn’t be any lingering artifacts left behind.

Sharpness

The Sony FE 14mm f/1.8 GM is a sharp lens throughout the aperture range. Only the corners at the wider apertures are anything less than great. Here’s how it performs in our lab tests:

The central performance here is some of the highest that we have ever seen. Midframes and corners look worse by comparison, but it’s a little deceptive – they’re still pretty strong. It’s just that the center is sharp enough to outshine the good (or even very good) midframes and corners.

You’ll see some comparisons on the next page of this review that put the result above into context. However, the short answer is that you have nothing to worry about with this lens’s sharpness. Even at its weakest – the corners at f/1.8 – the Sony 14mm f/1.8 GM is completely usable, and the corner sharpness steadily improves from there as you stop down to f/8.

In terms of other sharpness issues, I did not measure any focus shift on the Sony 14mm f/1.8 GM whatsoever, which I found very impressive. However, there is a bit of wavy field curvature that lowers the midframe numbers in the graph above. While field curvature is not a big deal most of the time, it can be a factor if you’re photographing an optically flat subject, such as an overlook where everything is at infinity focus.

Coma

Related to sharpness is coma, a lens aberration that can make dots of light in the corner of a photo look like smears. Coma is extremely important for Milky Way photography, and it was one of the main things that I wanted to test on the Sony 14mm f/1.8 GM.

First, here is the full image. The superimposed rectangles demonstrate how small of an area I’m examining in the central and corner crops below:

I took all the photos in this section at a quick exposure (for Milky Way photography, at least) of six seconds in order to eliminate motion blur. To compensate for the loss of light, I used higher-than-usual ISO values. While this does lead to more noise, the crops below have no star trailing as a result. This allows you to examine the effects of coma independently of any motion of the stars.

Test 1: Sony 14mm f/1.8 GM on Sony a7R V

Let’s look at the center of the image first for reference, then examine the top left corner. Here’s a central crop at f/1.8:

To keep this page manageable in length, I won’t be adding central crops at other apertures, because this is already excellent performance.

The real question is the extreme corner. Here’s how it looks at f/1.8, f/2, and f/2.8:

The images above speak for themselves, but this is really fantastic coma performance. The stars are pinpoints even wide open at f/1.8 in the corners – no visible coma at all. Stopping down is hardly necessary, although I see a very small improvement at f/2.8. (This isn’t because there’s less coma; it’s simply because the lens has sharper corners at f/2.8.) I consider this to be truly best-in-class performance.

Test 2: Sigma 14mm f/1.4 Art on Sony a7R V

The most exciting alternative to the Sony 14mm f/1.8 GM is the Sigma 14mm f/1.4 Art. It’s a substantially larger and heavier lens, but it costs about the same as the Sony and captures 2/3 stop more light. Here’s how it looks in the center wide-open at f/1.4:

Unsurprisingly, the Sigma 14mm f/1.4 Art has impeccable image quality in the center even wide open, just like the Sony 14mm f/1.8. Arguably, it’s even more impressive because the photo above was taken at f/1.4.

What about the corners? Here’s f/1.4, f/1.8, f/2, and f/2.8:

This is still excellent coma performance. However, it’s not as strong as the Sony 14mm f/1.8 GM, especially at f/1.8 and f/2. A bit of a surprise to me! Before testing these lenses, I would have predicted the much larger and more optically complex Sigma to outperform the Sony in coma.

My takeaway is that the Sigma 14mm f/1.4 Art only makes sense if you really need f/1.4. Otherwise, you might as well go with the lighter Sony 14mm f/1.8 GM for the same price. You would actually gain some image quality by doing so, at least where coma is concerned.

Test 3: Sigma 14mm f/1.8 Art on Sony a7R V

The Sigma 14mm f/1.8 Art is an older, DSLR-designed lens that Sigma eventually released in Sony E mount. It’s just as large and heavy as the newer f/1.4 version. Because of that, it’s definitely the least practical of these three lenses for Sony mirrorless today.

However, it still makes for a good comparison because of its long-running popularity among Milky Way photographers. (See our review.) How does it hold up? Here’s a crop from the center first, taken wide open at f/1.8:

As with the other two lenses, the central performance is excellent even wide-open. Nothing to worry about here at all.

Here are the corners by comparison:

The corners are the worst of the three lenses here. There is pretty significant coma here at f/1.8 and f/2. It’s much better by f/2.8, but still not as good as the Sigma 14mm f/1.4 or Sony 14mm f/1.8.

If you already have this lens, it may still be worth keeping. Compared to many other 14mm lenses on the market, it’s not bad at all – the newer Sigma 14mm f/1.4 Art and Sony 14mm f/1.8 GM are just that good. You can make your own judgments based on the crops above.

Test 4: Sony 14mm f/1.8 GM on Nikon Z8

Lastly, considering the excellent performance of the Sony 14mm f/1.8 GM, I was interested to see how well it adapted to the Nikon Z system. I used Megadap’s Sony-to-Nikon adapter for this test – a hollow adapter that does not have any glass elements of its own.

The following crops are from the same percentage of the frame as above. Since the Nikon Z8 has a 45 megapixel sensor compared to 60 megapixels on the Sony a7R V, these crops are a little lower in resolution. This doesn’t make much of a difference to my takeaways, however. What matters is the size of the coma relative to the size of the image, and sensor resolution doesn’t affect that too much.

Here’s the center of the frame at f/1.8:

It’s perfect here, nothing to complain about at all. The central performance is just as good on the Nikon Z8 as it was on the native Sony a7R V.

However, the story changes when you look at the far corners:

While the center is totally sharp – just as good as on the native Sony – the corners are much worse than they were on the a7R V. Moreover, stopping down does not really improve the situation.

This isn’t necessarily a surprise. We’ve found in the past that adapting lenses from Sony to Nikon usually harms sharpness in the extreme corners, likely due to different sensor stack designs. Milky Way photography is very demanding and only exaggerates these issues. On the FE 14mm f/1.8 GM, it manifests as the V-shaped stars you see above (which gradually begin to appear around the region corresponding to the APS-C corners).

My recommendation is for Nikon Z shooters to stick with native lenses like the excellent Nikon Z 14-24mm f/2.8 S and 20mm f/1.8 S. I would recommend against spending all that money on the Sony 14mm f/1.8 GM only for it to adapt sub-optimally to your Nikon Z camera.

Coma Summary

The Sony 14mm f/1.8 GM has exceptional coma performance. Even in the far corners of the frame, the stars look almost like perfect dots. Unless you need the f/1.4 maximum aperture of the Sigma 14mm f/1.4 Art, I think we can safely say that the Sony 14mm f/1.8 GM is the best Milky Way lens available for Sony right now.

That said, its performance does not translate when adapting it to other systems. If you shoot with a Nikon Z camera, you should go with a native Nikon Z lens instead.

Flare and Sunstars

Complex 14mm lenses tend to suffer from flare, and the Sony 14mm f/1.8 GM is no exception. However, it’s a little bit of an interesting case, because the worst flare with this lens does not occur when the sun is actually in the frame. As you can see, in that situation, the lens retains excellent contrast and does not have too much flare:

The bigger problem with the Sony 14mm f/1.8 GM is that the flare keeps occurring even when the sun is no longer in the frame. As you can see in the photo below, I pointed the lens a little further to the left and still saw flare appear:

Considering how wide the lens is, this could be a potential for concern. Chances are high that, at 14mm, the sun will be in or near a lot of your compositions if you’re taking pictures outdoors! It’s just so wide that it’s hard to avoid some sunlight landing on the front element. I often found little dots of flare sneaking their way into my photos with this lens when I didn’t expect it.

As a perhaps related issue, this lens sometimes generates rainbow-colored flare when the sun is right on the edge of the composition. The three photos below demonstrate this clearly. I took the sequence while tilting the camera progressively lower – note that the rainbow flare only occurs in the middle photo. All three images were taken at f/16.

This is certainly unusual behavior, and it’s something that you’ll need to watch for in the field. The good news is that your camera needs to be positioned in a very particular spot in order to get this rainbow flare. It’s usually something you can work around as long as you notice it.

Finally, the sunstars from the Sony FE 14mm f/1.8 GM are really nice, 18-pointed stars. They get very well-defined as you stop down to f/16. You can see that in some of the photos above, especially the first image in this section.

The next page of this review dives into the sharpness numbers a bit more, with some comparisons against other lenses that Sony users may be considering. So, click the menu below to go to “Lens Comparisons”: