Sony 20mm F1.8 G Review

If you’ve been a fan of this site for a while, you’ll know that I typically focus on reviewing third-party lenses (mostly due to Sony lenses being expensive). However, recently I was looking to grab a rental lens for an extended camping trip in Minnesota.

After much consideration, I decided I’d give the Sony 20mm F1.8 G a shot. I’d heard nothing but good things, and it looked like it offered optical perfection (ok, slight exaggeration) in a compact package.

So yeah, I ended up renting this thing out for a couple of weeks to really put it through its paces. Is this lens actually as beastly of a wide angle as everyone says it is?

Let’s find out.

Looking for a quick summary before jumping in?

Build Quality

Size & Weight

To start out this review, we’ll be talking about the size and weight of the Sony 20mm F1.8. Although I’m typically a fan of compact lenses in general, I was really shooting for something small this time since I’d be taking it camping/adventuring.

Size-wise, we’re looking at a length of roughly 3.3in (8.5cm). This is pretty standard for a full-frame lens and I found it balanced well enough on my a7iii. No size-related issues when tossing it in my sling.

As for weight, it comes in around 13oz (370g). Just like the dimensions, this is a pretty standard weight when it comes to a lens of this caliber.

Is the lens well-built?

Strong Materials

Now, since this is a G-series lens, it has got to be built like a tank right? Yep, it certainly is.

The Sony 20mm F1.8 G has a barrel that is primarily made out of metal. It has a sort of slightly textured/bumpy finish that just feels great.

For real, words cannot describe it. This lens, despite being fairly “standard” in terms of size and weight, just gives off such a premium, high-end vibe.

Accessories

With that being said, unfortunately, this lovely metal design doesn’t extend to the accessories.

The lens comes with your typical front and rear caps (pinch for the front, twist for the back) along with a small lens hood.

The lens hood is plastic, but it seems to be made out of some heavy-duty polycarbonate (oh, and it is reversible for easy storage). I was fairly careless and rough when taking it on and off, and it didn’t deform, dent, or scratch at all.

Weather Sealing

Fellow rain enthusiasts will be happy to know that the Sony 20mm F1.8 G offers pretty much full-weather sealing.

You’ll get: a gasket around the lens mount, internal seals, and some sort of special coating on the front element to repel water.

I didn’t get to test any brutal rainfall, but I did take it out in light drizzles and near a bunch of waterfalls. No problems at all when paired with my weather-sealed a7iii.

Built to last?

Typically in my reviews, I like to ask the question if a lens is “built to last”. It might be obvious, but I think this one definitely is.

Heavy-duty materials, full weather sealing, and it comes from a lineup of lenses (G-series) that is well known for their durability. Yeah, this thing will last.

Ergonomics/Usability

From an ergonomics standpoint, the lens feels awesome to use. First off, the relatively reasonable size and weight make it comfortable to carry for extended periods of time.

I have weak hands (lol), so a lot of lenses start to cause cramps and discomfort after a bit, but I was able to lug this thing around for a couple hours at a time with minimal issues (plus, it’s small enough to just toss in my bag when needed).

All the switches (there is a physical AF/MF switch by the way) and rings are easy to access and feel “good” to operate.

Aperture Ring

Speaking of which, this lens features a physical aperture ring! I absolutely adore aperture rings, especially when they’re done as well as the one on this lens.

The ring is incredibly clicky and feels awesome to use. Switching to “Auto” (or, in other words, body-controlled aperture) takes a little bit more of an extra push so you can’t accidentally bump it.

For those who prefer declicked rings, Sony actually included a handy-dandy little switch that lets you adjust it to your preference! I personally love the satisfying click, but I know many people (mostly video shooters) preferred a declicked ring.

Customizable Button

In addition to the lovely aperture ring, the lens also includes a customizable button.

I, to be completely frank, rarely use customizable buttons on lenses (I just sort of forget as I have everything set up on the camera body) but it’s always nice to see as I know it’s a feature many photographers enjoy.

Aesthetics

Next, aesthetics! I understand that beauty is often subjective, and the appearance of a lens isn’t nearly as important as… well, everything else, but I figured I’d touch on it.

I’ve always been a big fan of the look of Sony’s G lenses, and this one is no exception. The text engravings look great, the colors (bits of red here and there) contrast well, and the giant G is always iconic.

Image Quality

Sharpness

Alright, so now that we’ve got build quality, aesthetics, etc. out of the way, let’s get into the real meat and potatoes of the review: image quality!

Wide Open

So, wide open, this thing is a beast. Throughout my time developing this site, I’ve used a LOT of lenses (seriously, like way too many) and I’ve rarely seen wide-open performance this good.

As you’d expect, centers are razor-sharp. Corners, believe it or not, aren’t very far behind. If you pixel peep to the extreme, you may see some slight softness, but it’s really remarkable.

Stopped Down

In most lenses, stopping down a bit is necessary to draw out the full sharpness of the glass, but this one is already so sharp wide open that dropping your aperture just serves to (of course) get more depth of field.

Like, corners are almost razor sharp at F1.8, so they’re quite literally flawless when stopped down to even just F2.8.

Again, maybe an extreme pixel peeper might find an issue somewhere, but I personally can’t. By the way, this is probably a good time to mention that this isn’t sponsored (I’m sure it seems that way, lol!). Sony didn’t bribe me to say nice things (pssst… Sony: you’re welcome to send me free lenses anytime though…), this lens is just so damn well built and I love it.

Optical Quirks & Flaws

Now, with that all being said, some lenses are razor sharp but still suffer from issues like distortion, vignette, CA, and flaring. But this one… really doesn’t.

Distortion

Being a first-party lens, the built-in distortion correction is really solid. If you’re an architecture photographer or anyone else who takes pictures of straight lines, you might notice extremely minor bending if you look closely, but the performance really is quite impressive.

Using this thing in Minnesota, I naturally took a lot of pictures of (beautiful) Lake Superior. When I take pictures of lakes/oceans, I typically expect I’ll have to fiddle with distortion in post a bit to get an even horizon, but I just… didn’t with this one.

Vignette

Vignetting is also automatically corrected and looks great, but performance is a bit shaky if you (for whatever weird reason) turn off the automatic corrections.

With lens corrected disabled, we actually see some pretty heavy darkening of the corners when shooting wide open, but it is entirely remedied by stopping down to at least F2.8.

In most reviews, I add a little slide gallery showing uncorrected vs corrected distortion/vignette. There’s not much of a point with this lens, but I’ll include it anyway (barely perceptible).

Chromatic Aberrations

In all my lens tests, I try to force chromatic aberrations. Usually, I do this by photographing a car at midday or shooting backlit leaves against a sunny sky.

Continuing a common trend, the lens handles CA perfectly. I even shot a picture of my car’s emblem during mid-day sun (a typical “failure” for most lenses) and the purple fringing is incredibly minimal.

Flaring

Finally, flaring is also very well controlled. No lens is entirely immune to flare, of course, but the Sony performed exceptionally.

Even shooting directly into the sun, I could only get a tiny (TINY) amount of ghosting in the frame. See the photo below.

Bokeh & Subject Isolation

As for bokeh, you typically wouldn’t expect much out of a wide-angle lens, but the F1.8 aperture makes for some pretty decent background blur.

It’s not amazing, but thanks to the close focusing distance (more on that in a bit), you can get some nice blown-out backgrounds when shooting at F1.8.

Here’s a bokeh comparison for your reference (swipe gallery).

Overall Optical Performance

So yeah, overall optical performance was absolutely stellar. Was this one of the best lenses (optically) I’ve ever tested? Probably, yep.

That being said, image quality isn’t absolutely everything. We still have to touch on autofocus and a few other things…

Focusing System

Autofocus

So, everything else about this lens is fabulous, but how is the autofocus? Well…

Yeah, I have no complaints here either.

Stills AF

For stills, autofocus is absurdly fast. Like I mentioned earlier, I primarily test (rent/own) third-party lenses. These days, third-party lenses have excellent autofocus, but I quickly learned when using the Sony 20mm F1.8 G that they can’t compare to an OEM.

Seriously, the AF speed on this thing was frighteningly fast. When using AF-C (subject tracking), it blew me away how easily the lens kept focus locked. EyeAF too, despite being a wide angle, was pretty accurate as well.

Video AF

For video shooters, AF is also stupidly fast and also dead silent. There is also no focus breathing.

That, combined with the fact that this lens is a perfect focal length for recording yourself, makes this thing fantastic for vlogging.

Oh hey, this seems like a good time to mention: I also shot a video review about this lens! Feel free to give it a watch (and subscribe, maybe… :))

Manual Focus

But what if you prefer to do things by hand, so to speak? Manual focus works well and is enjoyable to use.

It is, like most modern lenses, focus-by-wire, meaning it’s electronically controlled. So, you won’t get any hard stops or perfectly tactile feedback like you would with, say, a Voigtlander, but I still found it enjoyable and precise.

Other Notes

Before we close out this review, there are a couple of random things I want to touch on.

Astrophotography

For those considering this lens for applications of astro, it is a fairly solid pick.

Coma control is pretty good. Not perfect, but pretty good. You’ll likely see a bit of minor star stretching in the corners, but overall it performed pretty well.

That being said, if you’re looking to do -exclusively- astro and nothing else, I’d suggest considering the Sony 14mm F1.8 instead.

Macro/Close Focus

Second, the Sony actually has a fairly close focusing distance. Minimum focusing distance is about 7in (18cm-ish). This is, of course, only about .20x magnification, so we’re not looking at a legitimate macro lens by any means.

But still, the close focusing distance does allow you to get some “fun shots” along with some highly detailed close-ups. The close focus and absurd sharpness allowed me to get some really pretty shots of various flowers and rain-speckled leaves.

My Final Thoughts

Alternatives

Anywho, before we finish this all out, I would like to offer up a few alternatives (at various price ranges) for your consideration.

Do note that, honestly, the Sony will be your best bet if cost isn’t a concern.

Samyang 18mm F2.8

A cheaper, budget-friendly alternative would be the Samyang 18mm F2.8.

Pros of the Samyang are that it is smaller and a LOT cheaper (more than 1/2 the price).

The cons are that, well, it’s weaker in every other way versus the Sony.

Tamron 20mm F2.8

Another commonly recommended lens in this focal range is the Tamron 20mm F2.8.

Just like the Samyang, it is smaller and even more cheap (seriously, this thing is dirt cheap, especially for an AF full-frame lens).

That being said it, just like the other alternative, is weaker in literally every single other way versus the Sony.

Conclusion

So yeah, in case it isn’t obvious by now, I absolutely love the Sony 20mm F1.8 G.

This lens offers pretty much everything I ever wanted in a wide-angle and, to be frank, I’m almost considering flat-out buying it now that I’ve had to send it back to the rental company.

Stupidly sharp, built like a tank, crazy OEM Sony AF. What more could you ask for? If you’re not on a hyper-tight budget and are looking for the, frankly, best wide angle you can possibly get, buy this thing.

I’ll leave purchase links (AMZ/B&H) down below. Thanks for reading, folks, and I hope you enjoy the lens as much as I did!

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Additional Sony 20mm F1.8 G Sample Photos

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