Test Images:Two pane image is comparison of corners at 200% zoom for Samyang 14mm SP F2.4 on left vs. Sigma Art 14mm F1.8 on right, both at ISO 3200 and 15 seconds. Note how sharp the Samyang is and perfect its stars are. The sigma produces much less noise in the same exposure time, or can shoot for a bit less than half the time for equivalent results. Denoise applied to each image, basic exposure matching in post.Both 3 pane images have Samyang 14mm SP F2.4 on left, Sigma in the center, and Tamron 15-30mm F2.8 right. All exposures were 15 seconds taken as wide open as each lens will get, at ISO 3200. Exposures matched in post, with denoise applied. Note the Sigma 14mm F1.8 pulls much more light and detail in the same exposure time and has much better noise. The ... MoreTest Images:Two pane image is comparison of corners at 200% zoom for Samyang 14mm SP F2.4 on left vs. Sigma Art 14mm F1.8 on right, both at ISO 3200 and 15 seconds. Note how sharp the Samyang is and perfect its stars are. The sigma produces much less noise in the same exposure time, or can shoot for a bit less than half the time for equivalent results. Denoise applied to each image, basic exposure matching in post.Both 3 pane images have Samyang 14mm SP F2.4 on left, Sigma in the center, and Tamron 15-30mm F2.8 right. All exposures were 15 seconds taken as wide open as each lens will get, at ISO 3200. Exposures matched in post, with denoise applied. Note the Sigma 14mm F1.8 pulls much more light and detail in the same exposure time and has much better noise. The main flaw is the coma in the corners. At 4K, especially if cropped 16:9, this will be not much of an issue. On a large monitor (65) I can notice the stars seems slightly fatter, but the zooms here are all at 200%. For timelapse, this coma will not be that noticeable, but the noise will. See the full frame image for a non zoomed look at the stars.This lens is heavy, and expensive. Obviously you need a good reason to choose it over similar 14mm options, or slightly less wide options of which there are many. For most of us the need for this lens is about being ultra wide and very fast at F1.8, and also sharp wide open. For my particular use I apply this lens for astrophotography and low light time lapse and video. For cases where F2.8 is good enough, I would suggest alternatives.To be quite clear, the coma of this Sigma Art lens is not greatly controlled from mid to extreme corners, so if perfect stars are an issue for you or you do big crops in on corners, there are better choices that save weight and money. The Samyang 14mm SP F2.4 (the latest version with low distortion) for example is about a stop slower, has worse vignette, but is sharper corner to corner than this Sigma wide open (if you get a good copy). The Samyang at about half the price and weight has almost perfect coma control to the far corners and very similar distortion performance. So, if you can stack exposures to deal with noise, better star results will come from that lens than this Sigma.However, if you need an ultrawide lens for single exposures or video that gathers as much light as possible, or you need to cut exposure times, or lower noise, etc. than you cannot beat the speed of this Sigma 14mm F1.8. The reduction in noise by this lens on star fields and other shadow areas is dramatic, as the nearest peer lenses are all 1.5-2.5 stops darker in the corners, and 1-1.5 stops worse in the center. Even on new sensors, if you are already at 3200 or 6400, being able to drop down 1-2 stops cleans up a lot of detail for timelapse.The build quality is good, and the lens copy was reliable on the first try, so I imagine this lens will not give me trouble beyond the cost and weight.For my use, this will be a valuable addition to the tool box and perhaps the best available on Canon. Sadly, Canon are not playing nice with the RF mount, as I suspect an RF version of this would be able to improve coma or speed or both slightly. For wide low light, this lens paired with the Samyang 24mm 1.4 is about the best combo possible as of 9/22 for Canon. Since the coma performance sis poor, I will hang onto my Samyang 14mm SP F2.4 for a while and use it on my second camera or for stills I can stack when needed, or when weight is an issue.For those who can deal with an FOV of 20mm, the lighter and newer Art lens is said to have great coma performance and might be a better purchase for Sony E and Nikon mounts (not available for other mounts yet).

The Sigma 14mm f1.8 Art is an outstanding lens, sharp and well built. I also own the 20mm f1.4 and 24mm f1.4 Art lenses. From my experience you absolutely must have the Sigma USB Dock. None of these 3 lenses focused properly out of the box with the 20mm being the worst of the three. And you really do need a focusing target like LensAlign or something similar. From my experience, Sigma Art lenses really aren’t calibrated to any standard so it’s important to use Sigma’s optimization software and calibrate your new lens at each of the distances shown in the software. Making adjustments at infinity is the hardest part. I found a distant object outside that had enough detail, so I could check the sharpness. But without a focus scale I found manually adjusting the focus ... MoreThe Sigma 14mm f1.8 Art is an outstanding lens, sharp and well built. I also own the 20mm f1.4 and 24mm f1.4 Art lenses. From my experience you absolutely must have the Sigma USB Dock. None of these 3 lenses focused properly out of the box with the 20mm being the worst of the three. And you really do need a focusing target like LensAlign or something similar. From my experience, Sigma Art lenses really aren’t calibrated to any standard so it’s important to use Sigma’s optimization software and calibrate your new lens at each of the distances shown in the software. Making adjustments at infinity is the hardest part. I found a distant object outside that had enough detail, so I could check the sharpness. But without a focus scale I found manually adjusting the focus as I looked through the viewfinder helped me determine if the lens was front or back focusing. This may seem like a lot of work, but I’ve found that once calibrated, those settings transfer to other Nikon bodies. Once adjusted on one camera body using the USB dock, I can use the lens on other Nikon bodies. However, with each new body it’s still important to use AF fine-tune to tweak the focus for that body. AF fine-Tune may be more important with these lenses due to their shallower depth of field.My main reason for purchasing these fast prims is for star shots, the advantage being the 2 or almost 2 extra stops of light. I can shoot at much lower ISO resulting in much less noise, no more star stacking to reduce noise. Previously, I’ve been using Nikon’s 14-24mm f2.8 and while it’s surprisingly sharp even compared to the sigma primes, f2.8 is too slow for astrophotography.So, what’s not to like? First you must calibrate the lens yourself. From all the testing I did, I also found the Sigma lenses don’t focus as consistently as the Nikon’s do. I could see this visually in the series of tests shots I took, and it was even more obvious when I used FocusTune software in conjunction with the LensAlign target. When FocusTune analyzes a series of shots, it produces a plot of the variation within the test group. In many of the Sigma test there was an inexplicable outlier or wild way out of focus shot. Even at their best the Sigma lenses had larger groups than the Nikon lenses. Where focus is critical, I often double check using manual focus, an extra step I don’t do with Nikon lenses.Weather sealing isn’t great either. Of the three lenses I own, only the 14mm f1.8 has a gasket on the flange and all were purchased since July 2017. I also discovered during a trip to the southwest, that a small grain of sand found its way into the focusing ring of the 20mm f1.4. I could feel the roughness when I turned the focus ring. Fortunately, I could see the tiny piece of grit and I was able to remove it with a brush and compressed air. In terms of astrophotography, I can’t say the 14 and 20 have reduced coma relative to other lenses like the Nikon 14-24mm. Stars in the corners develop some interesting shapes particularly in the 20mm, but I kind of like them since there shape reminds me of alien space craft. FX Corners on both the 14mm & 20mm when shot wide open are decidedly soft and don’t really become sharp until f8 or even f11 at the expense of reduced center sharpness. Also, at those f-stops you begin to encounter diffraction limitations.These are great lenses but if you don’t need a fast prime or you’re on a budget, the Nikon 14-24mm is still a very good lens. Sigma has also announced a new 14-24mm f2.8 Art lens that looks very promising.

This lens is way bigger than I imagined, but it was well worth the rental. I used it for shooting architecture, but I'm pretty sure I'll rent it in the future for some astro photography. Images are sharp, color is pretty clean and neutral, I didn't shoot it wide open at 1.8. I was a little worried about the depth of field being too shallow, but at 5.6, everything is in focus. It worked really well for my purpose. I used it on a Leica CL, which needed a firmware update before the lens could be recognized. I think the battery drained faster, but I have no idea why that would be the case, so that might be my imagination, or due to the new firmware. I would recommend this lens easily to anyone considering it. And as always, Lensrentals customer service was outstanding.