 This is the brand new 14mm f1.4 DG DN-ART lens from Sigma, and this lens was designed for astrophotographers specifically, and it shows. This is just a remarkable lens for shooting the night sky. I've been testing it the past couple weeks, and I have plenty to talk about and show you, including a direct Milky Way shootout between this new lens and the older Milky Way champ, the Sigma 14mm f1.8 DG HSM-ART. Since this video is a review, let me start with just a couple quick disclosures. Sigma America has lent me this new lens, the 14mm f1.4, ahead of its release, and they also supplied me with a Sigma FPL mirrorless full-frame camera here and other accessories like this EVF needed to complete my testing for the lens. I'll be sending all of this kit back to Sigma shortly after this review is posted. As usual, no money exchanged hands, and Sigma has no say in what I share in this review. I rented the older Sigma 14mm f1.8 from LensRentals.com so that I could make some direct comparisons in this video. And this video does have a sponsor, which is Brilliant.org, and I'll let you know more about Brilliant at the end. So, let me start with my biggest takeaways from using this lens, and then we'll jump into the fine details. I think overall, this is the best ultra wide-angle lens I've ever tried for astrophotography. Optically, it's just a masterpiece, as you're going to see from the tests. It greatly improves on the star shape in the corners over Sigma's older 14mm ART lens while being a full two-thirds brighter wide open. And then in terms of physical design, I am again very impressed. I don't have any other ultra wide-angle lenses that include this. What Sigma calls a tripod socket. I'd call it a lens collar with a foot, but no matter what you call this feature, it really aids in rotation, of course, and all as well as composition, stability of the system. And it's especially welcome if you plan to mount the lens on a Star Trek, or as I have here. There are two potential negatives with this lens, and I'll explore both, but in short, they're the size and weight of the lens compared to some of the competition in the mirrorless arena, and it's just quite heavy and bulky. And then number two, it's a focus by wire system, meaning even when you're focusing manually, it relies on electronic communication with the camera body, and that's to be expected with any of these new modern mirrorless lenses. But focus by wire does have some downsides, and I'll talk a little bit about that. So that's my review in a nutshell, but now let's get into the actual details. And let's start with comparing it physically to its predecessor, the Sigma 14 millimeter F1.8 DG HSM ART. I used both of these lenses with L mount, and I was using this Sigma FPL full frame camera. The new lens is a full frame lens, of course, and it's available on launch for L mount, which is used by Sigma Leica and Panasonic mirrorless cameras, and E mount, which is used by Sony mirrorless cameras. Since this is designed for mirrorless, it has a very short focal flange distance in the back. And so there isn't going to be a way to mount this lens to other types of cameras like Canon RF or Nikon Z kind of cameras. And I have no idea if Sigma is eventually going to release this lens for those camera systems, but I wouldn't hold my breath on that. This is in contrast to the older Sigma 14 millimeter, which was available or is available natively for Canon EF, Nikon F, Sigma SA, Sony E and L mounts. And because it was originally designed for DSLRs, you can take one of those DSLR versions and adapt it to many different camera bodies because it has a more generous focal flange distance allowing for many different kinds of adapters to be used, including ones officially designed by Sigma, which I personally use and are excellent. The new Sigma 14 millimeter weighs 1276 grams with caps on while the older Sigma 14 F1.8 comes in at 1238 grams with caps on. But if we take off the new lens collar and foot on the 1.4, it then weighs 1184 grams, so just a tad lighter than the old version. But in any case, these are both very heavy lenses. If we compare to a direct competitor for Sony E mount, which would be the Sony 14 millimeter F1.8 GM, that weighs just 460 grams. So if you're the type of astrophotographer who does a lot of backpacking to exotic locations, you know, definitely keep this in mind. This is by no means a lightweight lens. And it's also not particularly easy to pack with this big foot on it. That adds a bit of bulkiness to the lens. But other than that, it's the same basic dimensions as the predecessor. Now, for me, the trade-off of the lens getting bulkier and heavier is well worth it considering how useful I find a rotating lens collar. It does a couple things that I love. One, since this is a heavy lens, it puts the balance point closer to the right place where we want it. If we mount the lens and camera normally, it's going to be way too front heavy. Well, if we mount it here with the lens collar, the balance is much better. And then secondly, this allows for full 360-degree rotation of the camera and lens. When attached directly to my declination bracket here on my Star Adventurer, this is super useful when shooting something like the Milky Way, where I want the foreground in it as well, because I can very quickly level the horizon, get my foreground composed exactly how I want it, take my foreground picture with the tracking off on this Star Tracker, then turn the tracking on and get my tracked Milky Way shot, and they'll match up perfectly. Without this feature, you typically have to use a ballhead or other compromises that push the center of gravity away. And this is much easier to use. Along the lens barrel, we have some new additions that we saw on the other mirrorless art lenses, like the option to change iris with a ring, the manual focus lock switch, and the lip up here, so that the dew heater doesn't accidentally slip into frame, which is again a really nice and much appreciated addition. Like with the previous 14 millimeter, there is a place to put some sheet type gel filters in the rear here, but something new on this lens is they now have a place to store your cut down sheet filters in the lens cap, which I thought was a pretty cool little thing to add. I didn't have any custom cut sheet filters to test this all out with, but it's still pretty neat. Last thing here to talk about is the physical design of the focus system. Traditionally, with manual focus, the focus ring is mechanically actually coupled to a group of lenses inside the lens, and it moves them back and forth. So there doesn't have to be any kind of electronic communication to focus the lens. It's done actually manually. With these new lenses designed specifically for mirrorless cameras that are focused by wire, that's not the case anymore. These kinds of lenses need to get power from the camera body and be able to communicate with the camera to focus the lens at all, even when you're focusing manually, because focus by wire means the focus ring does not have any actual hard stops in here. I could just keep turning it because it's not mechanical, it's electronic. When you move it around, it's just a little wire sending information to the camera about the speed and the distance that you're moving this ring. And then the camera sends information back to the lens for how to move those lens elements to focus manually. So it means, unless someone comes up with a really pretty crazy, very thin, smart adapter, we're never going to be able to adapt these kinds of focus by wire lenses to astronomy cameras. Now, one cool thing about Sigma's implementation of this focus by wire system is they've put in a manual focus lock. And so you switch that lock on and then you don't have to worry about bumping your lens at a focus when, for instance, you put the dew heater strap on because you're literally locked the focus position electronically and this ring isn't going to do anything. It's going to stay focused until you unlock it. All right, let's now move on to the optical tests, which I'll show on the computer. And these were done, of course, on the same night under dark night sky. I'm going to cover vignetting, corner performance, center performance, and just sort of overall impressions. And these images you're about to see were captured with this setup right here, which is the Skywatcher Star Adventure 2i Star Tracker. It's on an i-footage carbon fiber tripod. The camera is a Sigma FPL, which is a full frame camera with 3.8 micron pixels. I did use the EVF to help aid in focusing and I captured these images in the White Mountains of New Hampshire. So it's fairly dark, maybe a Bortle 3, but it wasn't a perfect night. I did get some haze and maybe low clouds and maybe some light pollution from a nearby town, but we take what we can get out here on the East Coast. It was my one completely clear smoke-free night during the new moon period while I had this lens, so I'm happy to be able to capitalize on that. Okay, let's start with vignetting, which I could describe briefly as how much light fall off there is from the center of the frame to the corners. You could also call it shadowing of the corners. And this is actually very good for a 14 millimeter lens at 1.4. I was pretty impressed by how little vignetting there was. There is obvious vignetting, but it could be much worse just based on other results I've had with fast wide angle lenses. So comparing that, there's no comparison here to the DGHSM version of the lens because it doesn't go down to f1.4, but if we go ahead to 1.8 and now we're just looking at one half of each frame, you can see they're pretty comparable. I don't see a huge difference in the amount of vignetting and I wouldn't say that there was a huge difference between 1.4 and 1.8 in terms of the vignetting on the DN version of the lens. Now at f2, I think that the DN version of the lens is actually looking better. It's brighter all the way to the corner than the HSM version, just slightly. Not a huge improvement in vignetting, but I mean it's definitely noticeable. And I would also say at this level, f2, I'd be happy with either of these. It's not, it's very mild effect. It's not a huge deal. At f2.8, the HSM version catches up to the DN version and again, they're both looking quite good here. And then at f4, I would call both of these fields flat. They're not showing really any vignetting or hardly any at f4. Okay, and now we're on to center crops. These are done at 300% zoom. Again, we're starting at f1.4 where only the DN version of the lens can go. And this looks pretty good. This is a field right in the center of the Milky Way in Sagittarius. This is the Sagittarius star cloud right there. And this is the Lagoon and Trifid Nebula down here just to give you some context for what you're seeing. Now we're at f1.8. And I want to make a quick note here about the difference in the contrast of the dark nebula. These were done at slightly different times because I had to change out the lens and all of that. And the Milky Way did rise higher by the time I got to this lens. It was probably, you know, half an hour later. So any difference that you're seeing in color is probably just because the Milky Way core was higher in the sky. So really what we're comparing here is just critical sharpness. And we can zoom in a little bit to try to judge that. And again, this is at f1.8. And if I just look at the star cloud here, or just sort of the stars in general, they do look a little bit sharper in the new DN version versus the HSM version. Okay. And then here's f2. And as you'd expect as you stop down the lens, they both get sharper. But I think that the, I would say that the HSM version makes a bigger stride between f1.8 and f2 while the DN version of course is already making a pretty big stride from f1.4 to f1.8. So at f1.8, it's already as sharp as this lens is going to be at maybe f2.8. But then at f2.8, this one has sort of leveled off in how sharp it can get. So now they're a lot more equalized. So this is all pretty interesting because if you're someone who's concerned with the sharpness of your ultra wide angle lens, you can sort of think, well, if I'm planning to stop them down to f2.8 anyways, it might not be worth getting this new lens. But if you're the standard Milky Way shooter who likes to shoot very fast, then this new lens is definitely going to be worth it because you could shoot at f1.8 but get the sharpness results of this older lens at f2.8. So it's definitely considering they're also the same price at $1,600. It's definitely going to be something to consider. Okay, and then at f4, they're again pretty equal. And again, the differences in color here are just because of the altitude of the Milky Way core at that time of night. Okay, and then for the corner comparison, this is where I think it gets the most interesting because there's the biggest difference between these two lenses. I zoomed into 500% because I really wanted to make it clear, even if you're watching this on your phone or something on YouTube, the difference here between the corners on the new DN mirrorless lens versus the older HSM lens designed for DSLRs. This may look soft and a little bit distorted compared to what we just saw, but for a 14 millimeter lens at f1.4, this is an amazing performance. You'll see here in a second what I'm talking about. There is just a little bit of distortion away from center where the stars are a little bit elongated, but it's fairly sharp. We're seeing a lot of stars, meaning it's sharp. We're seeing a lot of small stars at f1.4. Now, if we go to f1.8, and then this comparison lens comes in, what I hope you can see here is we're seeing many more small stars in the background. While in this one, it's so blurry, we're not seeing a lot of those faint background stars. The other thing that should be very evident is on bright stars over here with the new DN lens, we're just seeing a little bit of elongation in the corners, in the extreme corners of a full frame sensor, right? Well, with this one, we're seeing a lot of astigmatism. That's what gives it this sort of bird-like shape here, right? Where these little wings come out of the star. And this is what I find pretty ugly in wide-angle lenses generally. And the old HSM lens, this was one of its main faults, I would say, technical faults, is it had this astigmatism in the corners of the lens. Well, this one doesn't have it at all, it just has your standard distortion, just a little bit of elongation, which this one has too, right? These stars are a little bit elongated this way, then they also have this astigmatism distortion going this way. This is at f1.8. Here's at f2. You can see this lens sharpens up a little bit. You're seeing more background stars, but it still has pretty heavy astigmatism. This lens still has the distortion, and the main thing that I would say changed between f1.8 and f2 is the vignetting really went away. That's why this field got so much brighter. But the distortion is still there. Okay, and at f2.8, the distortion is starting to go away, and the distortion and astigmatism is starting to go away in the HSM lens. So it's starting to catch up just like what we saw with the other tests, they really start equalizing around f2.8. And then at f4, this lens I think still shows a little bit of weirdness with the star shape. This lens, the new DN lens, gets almost perfect. I mean, if you're really pixel peeping, you can see a little bit of distortion still, but this is a pretty amazing for the extreme corner at 14 millimeters at f4. Anyways, my overall impression of this new lens is, like I said at the beginning, the most impressive lens technically I have ever shot with. Now, that doesn't mean that it's going to be perfect for everyone. Some people may want something a lot lighter weight that they could go backpacking with or travel with more easily. But if you want just sort of the ultimate 14 millimeter lens in terms of how it renders a star field, so there's nothing holding you back in terms of the optical perfection of the lens, I would go for this one. I'm very excited to be sponsored by Brilliant. Brilliant.org is the best place to go if you want very engaging interactive lessons for learning science, math, and computer science. Lately, I've been pushing myself to learn about complex numbers and advanced algebra, and I wouldn't have guessed it, but this has actually been one of my favorite courses ever on Brilliant. I'm just always surprised by how things are related to one another and how this kind of mathematical problem solving on Brilliant actually does help me with day to day problem solving in weird, unexpected ways. 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