Sigma 210101 18-35mm F1.8 DC HSM Lens for Canon - Black

Product Information

Despite its limitations when shooting stills, the Sigma 18-35mm f/1.8 is surprisingly great for video on the R5. Here’s why. Large f/1.8 aperture

Sigma, 18-35, 1.8, DC, HSM, Art, Canon EF - HDEW CAMERAS

For clarity, you're suggesting taking the 18-35mm F1.8, and add a 0.71x Speedbooster/focal length reducer. The lens seemed to do best within about 8 feet, but in the crucial portrait window of 8-15 feet (for full body shots) the focus accuracy dropped dramatically. This reveals one of the problems I (and others) have experienced with the lens. You can set an effective microadjustment value for a certain distance, but that value may not be the right one for other distances. The Canon EOS R5 is, however, smarter than the 5D. The R5 recognizes the Sigma 18-35mm’s crop factor and automatically changes its Cropping/Aspect Ratio setting to “1.6x (crop)”. APS-C lenses automatically enable “1.6x (crop)”. All other options disabled.Since the lens is designed to be used on a camera with smaller sensor ('APS-C') the focal length will be equivalent to29-56 mmif you have a Canon camera or27-52 mmif you have a Niko camera. In this set of evaluations, we’ve compared the Sigma zoom with the highest performing full-frame primes of the same focal lengths – 18mm, 24mm and 35mm. While it might seem a little unusual, the lenses (all high speed models) reflect the state of the art in that format and when mounted on an APS-C DSLR offer the same angle of view (at each focal length) as the Sigma. The Sigma 18-35mm F1.8 DC HSM | Art gives the same control over depth of field that full-frame shooters are used to with constant F2.8 lenses. Photo by Barnaby Britton A consequence of all of this is that in principle you'll get the very best results at large apertures by focusing and shooting in live view. This has its own pitfalls though - for example when focusing manually with Nikon's DX SLRs you have to remember to set the aperture to F1.8 before entering live view, as they're incapable of adjusting the lens's diaphragm during viewing. If you initiate live view at a smaller aperture, then you risk getting misfocused images. Meanwhile Canon users may have to set the aperture to F1.8 and press the depth of field preview button to force the lens wide open for accurate manual focusing, when shooting in bright light. Autofocus microadjustment

Sigma 18-35mm F1.8 DC HSM A Canon - DXOMARK

The HSM (Hyper Sonic Motor) ensures a silent, high-speed AF function. Optimizing AF algorithm, smoother AF is achieved. It also enables full-time manual focusing capability which allows sensible focus adjustment by simply rotating the focus ring. This will make it so much easier shooting in darker environments where you do not want or can use flash lighting, for example in churches or at different sports venues.In the fourth sample we've zoomed in to 35mm and placed the sun just outside the frame. The lens does particularly well here at maintaining contrast and shadow detail. I use this on Canon 70d and cannot get the auto focus to work in a friendly way. I can easily point the focus one one point and have the camera confirm, but focus on a different point. When I look at the picture I see the focus point where expected, but focus is somewhere else. So problem of consistency is more than soft images when pointing to the target, the camera might focus o something else entirely. And that's really the key to understanding the impression that I got: that it is what it isn't. And that it is what it is. Bear with me on this. It is what it isn't.

Sigma 18-35mm f/1.8 DC HSM Art Review - Photography Life

At 35mm F1.8 things are slightly different- if you shoot a flat scene straight-on you'll see a gradual drop-off in sharpness right across the frame. But this mainly due to curvature of field, so if you shoot something three-dimensional then objects in the extreme corners will look sharp if they happen to be in focus. The lens shows practically no chromatic aberration at 35mm, either, which means that the images look very clean indeed. Overall, this kind of image quality is remarkable coming from an F1.8 zoom. Autofocus accuracy and consistency ISO in the digital era (in an attempt to mimic ISO, DIN and ASA from the film era), is a per-unit-area perspective. But if you view the output images at the same size, then a per-image perspective is also pertinent. Because an f1.8 APCS lens on an APSC sensor DOES gather the same total amount light as a f2.8 FF lens on a full frame. The APSC lens focuses all that light on a smaller circle, the FF lens focuses it on a larger one. But they both gather about the same number of photons in the same time. I have used it in the studio and out in the field. As the DOF is so shallow at F1.8 it works far better in continuous focus mode when anything like close. As even the slightest movement will throw it out of focus ! This lens gives full frame equivalent 24 to 52 mm which means that now there is a zoom lens that will cover all the sizes you need for everyday indoor photos of family and friends that is brighter than any equivalent ff zoom that I know of.The other take-home message here is that, while our copy of the lens showed a tendency towards focusing in front of subject (and therefore required positive microadjust values), the correction needed at each setting was different. So using a global in-camera microadjust value would necessarily be a compromise - setting a value to correct any given focal length and subject distance could throw off the focus at other settings. We observed this in practice using the Canon EOS 7D's microadjust feature - it could only be set to give optimal focusing at one given focal length and subject distance. Are we looking too closely?

Sigma 210101 18-35mm F1.8 DC HSM Lens for Canon - Black

Distortion is kept reasonably well under control - it certainly doesn't exceed what we'd expect for this kind of lens. There's visible barrel distortion at wideangle, turning to pincushion distortion at the long end, but no more than you'd get from any other premium standard zoom. Why not sign up to our newsletter and receive info on exclusive offers each week that are not available to the public. Voucher codes with money off, free gifts and much more:

Getting the best possible focus is the responsibility of the camera. Some lenses (usually through decentering or spherical aberration) make it impossible for the camera to achieve optimal focus. But a good copy, and in particular after micro-AF-adjustments that can deliver spot on AF, should do so every time (within small tolerances, of course). In fact you are mostly right, and I agree with you. It could be most probably problem on side of Canon. But still as Canon is not doing their cameras to be suitable with third party lenses, then the fact that third party lenses are made to be suitable with the particular brand (in this case Canon) make them responsible for all failures. The 18-35mm is remarkably sharp even wide open at F1.8, and in the wider half of its range (18-24mm), there's no measurable increase on stopping down (i.e. the lens is effectively diffraction limited). At the longer end (28-35mm) there's a slight improvement in sharpness on stopping down to F4, but in practice it's unlikely to be especially noticeable. For an F1.8 zoom, this is little short of astonishing. Optimizing quality with our integrated production system, Sigma is focused on making things right, with our own hands and our own techniques. We are now one of the very few manufacturers whose products are solely “made in Japan.” We like to think our products are somehow imbued with the essence of our homeland, blessed as it is with clean air and water, and focused, hard-working people. We pride ourselves on the authentic quality of Sigma products, born of a marriage between highly attuned expertise and intelligent, advanced technology. Our sophisticated products have satisfied professionals and lovers of photography all over the world, because our manufacturing is based on genuine craftsmanship, underpinned by the passion and pride of our experts." That is one of the advantages of designing lenses for smaller formats. Despite the relatively high imaging performance of the Zeiss, some chromatic aberration is noticeable in the corners of the frame though distortion and vignetting are at similar levels. Be that as it may, as our results show, at 18mm the new Sigma lens is much more suited to the APS-C format than the Zeiss.