As usual, the barrel distortion is corrected as the focal length increases until essentially being gone at around 22mm.

As I said before, the Sigma 18-35 has been a great lens to have available for around-the-house use and has been glued to my 60D since it arrived. Zooming to 24mm improves sharpness. At f/1.8 the lens scores 2,470 lines, and it peaks at f/4 at 2,690 lines. At 28mm the lens manages 2,457 lines at f/1.8 and improves to 2,562 lines by f/4. Zooming all the way in to 35mm delivers 2,399 lines at f/1.8 and peaks at 2,528 lines at f/4. Edge performance when zoomed in a bit is consistently good; better than 1,800 lines at every tested focal length and aperture. When asked if the limited focal length range design was necessary to keep the lens size manageable and the cost affordable, Sigma responded: Coma ( saggital coma flare) often causes weird smeared blobs to appear around bright points of light in the corners of fast or wide lenses at large apertures. In lenses that have it, coma goes away as stopped down. Amateurs waste too much time worrying about lens sharpness, and since this lens is designed for amateurs, it's super sharp.The Sigma 18-35mm f/1.8 is an affordable lens with fantastic “Sigma Art” image quality, sharpness, and performance when shooting video on the Canon EOS R5. Its large aperture is well suited for shooting video in low light environments, its “35mm effective” 27-52mm focal length is just right, and you may capture high quality 4K video without overheating. Sigma is organizing all its interchangeable lenses into three product lines; Contemporary, Art and Sports. Designed with a focus on sophisticated optical performance and abundant expressive power, our Art line delivers high-level artistic expression. Developed with the maximum emphasis on artistic touch, they are designed to meet the expectations of users who value a creative, dramatic outcome above compactness and multifunction. Along with landscapes, portraits, still-life, close-up and casual snaps, they are perfect for the kind of photography that unleashes the inner artist. Ideal for studio photography, they offer just as much expressive scope when capturing architecture, starry skies, underwater shots and many other scenes. I don’t understand what is being said here. Are you folks referring to an MFT mount or a Sony E-mount? If so stop calling it a mirrorless mount because the EF mounts are on mirrorless camera as well and the 18-35 comes in EF mount which can be used on the BMD cameras and others that are mirrorless. Ask for MFT or E-mount instead. When used on a DX or APS-C camera, it sees an angle of view similar to what a 28-55mm lens sees when used on an FX or 35mm camera. In this box sits the lens inside a plastic bag which sits with the hood inside the case. The case is the padding - there is no foam.

As good as the Sigma 18-35mm f/1.8 may be for video on the R5, it does come with a few downsides to be aware of. Size and weight A wide angle lens with a wide aperture, sharp across-the-frame wide open aperture image quality and low vignetting begs to be used for night sky photography.MFT, E Mount, RF all have a very short flange distance from the sensor as they have been designed to be used on mirrorless cameras. Canon's EF, Nikon's F and the cine PL standard mounts have all been designed to accommodate cameras with reflex mirror mechanisms and so required much longer flange distances to allow for the space the mechanism requires. From this example, we can see that the 9-blade aperture delivers rather smooth out of focus highlights with a touch of bright edge.