I've been shooting on Sony E mount cameras since 2012. That seems like a pretty good way to preface this, so you know that I've seen a lot of lenses come and go. I'll give you a little bit of background on my usage case and then show you some sample images and side-by-side comparisons with the Zeiss Batis 18mm f/2.8.
I've had most of the Sony and Zeiss E mount lenses on my camera at some point over that span and have longed for, and then seen many perspectives fulfilled. 35mm f/1.4, Check. 85mm? Check. 25mm? check. 70-200? Check. But I've always wanted something wider. 24mm just isn't wide enough for many landscapes or Night sky scenes.
I've been a fan of ultra-wide angle lenses for awhile, but I had held off from adding a premium quality one to my camera kit for a couple reasons. Aperture, bulbous front elements, and optical defects like coma and blurriness in the corners. I owned the Rokinon 14mm f/2.8 for a couple years and was never very happy with it.
A couple years ago after renting it a couple times I finally purchased the Zeiss Batis 18mm f/2.8 and it has been in constant use since. It's a superb lens in nearly every way, very similar in character to the Batis 25 which I've owned for about 4 years. Sharp into the corners even wide open, with fast autofocus and robust construction. That said, I found myself wishing it had a larger aperture for Night Sky photography. Many of my Milkyway images over the past year have been made as Pano's with Faster, but longer focal length lenses. I've considered the Sony 24mm f/1.4 GM off-and-on over the past year, but Ultimately felt that the focal length was wrong for my use and I already have a great 25mm f/2.
So when Sony announced they would be releasing a lens that would get Astro photographers excited, my ears perked up.
Enter the 20mm f/1.8 G.
I reached out to my local camera store, Pro Photo Supply and had them add me to the preorder list nearly as soon as the announcement was over and I've been shooting with it since release day!
First things first. This lens is really well made. It's got a bunch of great features, like an aperture ring, an AF/MF switch, declickable aperture and a Focus hold button. For comparison, the Batis has none of those, but does have a really cool OLED Distance scale. Both lenses are fairly small and lightweight and the Autofocus is pretty much the same and as fast as any other Sony lens I've tried. All of those are great features, but what I'm ultimately concerned with is image quality.
I figured I'd let the results begin to paint a picture. Some of these photos are simply nerdy pixel peeping. I've also included a few that are more artistic and push the performace edges- think flares, direct sunlight, Chromatic aberration, that sort of thing. And hopefully the comparisons will give you a sense for areas where each lens shines and what they do differently. For me, there's the question about how much difference the 2mm makes, whether it's noticeable, useful, and if it's worth keeping both lenses.
Pixel Peeping
Weird Diagonal Photos
Ok, Here’s where it gets nerdy. This is a series of shots taken with the Sony and the Zeiss Batis 18mm taken at all the 1/3 stops, plus 1.8 and f/2 on the Sony. You can just click on the first one and then scroll through them with the arrow keys. I shot them this way so you can see what’s happening in the corners as that’s where you can see a big difference in wide angle lenses.
My eye sees some minor differences right off the bat. There’s a slight difference in cast with the Zeiss being slightly more magenta, and the Sony leaning green. I say that because on their own, neither looks bad, or in need of correction, but either can be “corrected” the other way.
Both lenses have some vignetting at their widest aperture, which is eliminated for the most part by stopping down. On the Sony, that means f/2.8, on the Zeiss, f/4.
Corners
This second set is a 200ish% crop from the upper Left hand corner. This is the place where you are gonna see the most shortcomings. Obviously the lenses are a little soft in the corners at open apertures, but that’s common on such wide angle lenses. It’s also pretty interesting to see how much diffraction affects image quality at the smaller apertures. Having used the Zeiss quite a bit in real life shooting, I can tell you that the small bit of softness in the corners isn’t something I even notice.
Putting details in the corners and then zooming in like this is the harshest sort of test out there and It just goes to show you that your lens generally performs best in the middle range. They both get to about maximum sharpness in the corners at about f/5.6 and there’s noticeable degradation in image quality at f/16.
Center
The last set of nerdy pixel-peeping crops is taken from right around the center of the image. I moved it down just a bit and straightened it just to get some good detail and make it a little less vertigo inducing. What I’m seeing is that the Sony lens is pretty much as sharp as it’s gonna get in the center of the image, wide open at f/1.8. That’s pretty impressive and a really important feature for a lens that’s marketed for night sky photographers. The Zeiss is sharp at 2.8, but does get just a tiny bit sharper at f/4.
As far as comparison, they are both very sharp and resolve detail beautifully. Both begin to lose image sharpness at f/16 and both are very sharp and clean at their largest apertures. Perhaps the Sony is a tiny bit sharper, but that difference could be perception due to the slightly shorter focal length. If I were only to go off these boring shots focused to give maximum Depth of Field, I’d say that they perform nearly identically functionally.
Character
Zeiss on the Left, Sony to the right. -f/2.8
People often talk about lenses having character. This language is usually associated with how a lens renders the transitions between areas that are in focus and those that aren’t. It usually includes things like flares, sunstars, the shape and patterns of Bokeh Balls. I’ve added a few images in this section that are stand alone examples as well as some comparisons with the Zeiss.
These images show a couple key things about these two lenses. First of all, in the first two images taken at f/2.8, the Depth of Field is just a little shallower on the Sony. This is to be expected because of the slightly longer focal length. These flowers are only about 6 inches in front of the lens, which exaggerates the difference. If you take a look at the Bokeh Balls, you’ll also notice that the Zeiss has a small amount of Onion Ring pattern. The Sony Doesn’t. In fact the clean, circular pattern rendered by the Sony is consistent with the G Master lens line. One more reason to wonder why they labeled this one with a G.
The last two images are made at f/1.8. The first one, composed from the same spot, and the second, closer and turned to get a better composition with the shallow depth of field. Also, there was an ant on the flowers I was following.
Sunstars are one of those things people get excited about. They aren’t something you will always care about and they aren’t necessarily indicative of high lens quality. It is a specific effect though and when it’s not there some people miss it. In this case, the images were taken about 2 minutes apart. Just long enough to swap out the lens and get it all set up the same.
The Batis spreads out the effect, giving almost a slight warmth to the corner of the image, instead of the sharp, pronounced intrusion into the scene of the Sony. I’ve heard some people mention that a clean sunstar usually coincides with less veiling flare, but I’ve not seen enough evidence to convince me that it’s always true.
Landscapes
I’m a sucker for wide angle landscape images and man I’m addicted to chasing waterfalls. TLC wouldn’t even talk to me. I figured, what better way to really test this lens out than to take it out into the forest and make some of my favorite kinds of images. Water, Sunlight, Mist, all that dramatic stuff.
Full Disclosure- this is a fully edited image, but only edited in Lightroom. This was an incredibly contrasty scene, with the area under the log, nearly black and the highlights right on the edge of clipping. I’ve applied the exact same processing to each image.
What I’m seeing here is an incredibly similar rendering. Sharpness, color fidelity, contrast. Similar.
Do I see any difference other than the field of view? Yes, but it is ever so slight. I see a slightly broader tonal contrast in the Zeiss image. Look in the areas with rich midtones like the moss on the right end of the log or the rocks in the foreground.
With this particular composition, that additional field of view is nice, but not critical and I see very few times when that extra 2mm would be. That said, I’ll be updating this review if at some point I find a situation when it does.
Astro Photography
First of all, before you read anything below, The COVID-19 crisis is happening. That means my outings to test it out were cancelled. [Update- I went shooting!]
One of the primary reasons I was interested in this lens is how well suited its technical specs are for Nightscape Astro Photography. About a year ago I started thinking differently about this type of photography and started actively moving away from Stacking, Blending and using Tracking. I have no issue with anyone that uses these methods, but I felt a lack of joy in making images this way.
That’s all well-and-good, but the reason these methods exist is to deal with the limitations of the camera and lens combinations most people have. If you can add a full 1 and 1/3rds stops of light, that’s significant. From the beginning of reconsidering how I make these types of images, I knew that a faster ultra-wide angle lens would be something I’d be looking for. In the last year, I’ve been using my Sony Zeiss Distagon 35mm f/1.4 and my Zeiss Batis 25mm f/2, but in order to achieve the wider field of view, I’ve been shooting panoramas. While also a legitimate method, It’s not what I had in mind in my quest to simplify things.
I’m the target market for this type of lens. This lens is remarkably sharp in the center wide open, which bodes well for Night Sky photography, but I really want to see how the corners do as well. I suspect it will be very good as the Batis does great, and the corners look similar in my day time testing.
So far, it’s been a lot of full moons and cloudy skies since I got my hands on this lens. I’m saying all this to let you know that one of my goals this spring and summer is to really put this lens through the paces shooting the Night Sky. I’ll update this review when I do.
Update- Astro Photos Taken!
So, here’s the update- I was able to get this lens out under some incredibly dark skies in late May this year. I shot a ton of images pointed at the Milky way at different apertures and I also made a few comparison images with the Batis 18mm f/2.8.
These were shot at around 3:30 in the morning after about an hour watching the clouds race by overhead. I was camping with my kids and we actually had to tear down our tent and camp at 12:30 and put everything in the car due to some 40+mph winds and rain, only to see the wind die down and the clouds clear out an hour later. I wasn’t able to got back to sleep, so I just stayed up and waited and it paid off.
These first two images are identical except for aperture. 2.8 on the Left and 1.8 on the right. They are both shot at 5 seconds, with an ISO of 8000. I know that’s pretty high, but I wanted to keep the shutter speed low so I would be sure to have no trails in the stars or wind shake. I adjusted the exposure in post- for comparison. I’ve also edited for some basic overall aesthetics so they are kind of close to what I’d release into the world. I’d probably do more noise reduction and probably work some on alleviating the color noise in the foreground, but I wanted to give you a sense of what that extra light does without too much manipulation.
And just in case you actually watch what I release into the world- and see it posted down below, I am working on a composite with the 1.8 image and some big chunky mud tiles we found earlier in the day. I’m not usually big on composites, but in this case, due to the weather and the real threat of accidentally driving onto wet tiles in the dark and getting stuck, the composite will have to do.
I’ve also included a 100% zoom into the upper right hand corners so you can see how this lens does where these types of wide angle lenses are weakest. As you can see, there’s just a little bit of coma wide open at f/1.8 and slightly less at 2.8. But, that being said, the amount that shows up at both apertures is totally acceptable.
What I’m seeing is a significant reduction in noise with the faster aperture. About what I expected. In my experience, the difference I’m seeing here is about what I’d expect to gain from a 10 image stack. In addition, I’m seeing additional detail in the faint formations on the middle right side of the image, the Rho Opiuchi Cloud Complex. This part is Only visible in very dark sky conditions, but the dark sections that reach into the Milky Way core are usually one of the places that noise shows up most prominently in Milky way images. For that reason I’ve included a zoomed in sample from this area.
How does it compare to the Batis 18 at Astro?
So how does it compare to the Batis 18mm f/2.8? Good question, and thankfully, I brought both lenses out to the desert. I didn’t take a ton of photos, but just enough to get a sense of whether there’s a significant difference. What I’m seeing is that the overall color is nearly identical, and if anything is different, it’s that the Batis is wider and because of that it has a little bit more distortion in the corners. Also, I’ve turned off all lens corrections here and you can probably see that the Batis has more vignette in the corners. To be fair, the Sony has a bit of vignette in the corners when opened up to its maximum aperture, but the ability to stop down and eliminate that vignette is a definite plus. These images are both taken at ISO 6400 for 10 seconds.
Summary
I’m a big fan.
Is that succinct enough for you?
But seriously, I can’t really find any flaws with this lens so far. Image quality is superb. Size, weight and controls are just about perfect. I recently had a conversation with a few friends during our current March 2020 quarantine and after telling them all about this lens and showing them some comparison images they asked which lens I’d recommend to someone who didn’t already own something in this focal length.
Price on this lens is $899. The Price for the Zeiss Batis 18mm f/2.8 is $1,499. That’s a pretty big premium for image quality difference which is hard for me to see. I plan to bring both lenses out on landscape shoots once I’m able, and I’ll update this review as I learn more and am able to compare in more situations. I suspect and have already noticed in small ways that the Zeiss will have a little bit of an edge in really contrasty extreme light conditions.
[Update- as of October of 2020, I’ve sold both of my Zeiss wide angle lenses and replaced them with the Sony GM 16-35mm f/2.8. While I loved those Zeiss lenses, I ended up needing a wider lens for real estate work and couldn’t justify keeping all of them. I did have a chance to use the 18 in some more extreme light, but it never really performed better as I’d hoped it would. If anything, it solidified my statement below.]
As of right now, they are so close I’d have to recommend the Sony. Extra light gathering ability, better sunstar and Bokeh, smaller size, more controls. Seems like a pretty clear win.
I buy most of my gear at my local pro camera store, but If you decide to order one online and use this link- I’ll receive a little commission.
Below is a big gallery of random photos I’ve taken with this lens over the last couple weeks. I’ll add to it as I test more.
If you’ve got any questions, please leave a comment, or reach out on social media! Links are over on the side bar.
