and I did a test with different apertures.Īnd the test showed that there are issues. But nothing about back or front focusing. They stated that problem is because lens has very high resolution so camera can't handle. Telling only about pause in videos, which is also stated here in forum. I asked 3 dealers and official importer of Sigma about focus issues of this combination, but all of them denied this. Fortunately there is demo item to test, but still not in all shops. Here shops don't allow to test the lens before you buy. Though I am not resident of Turkey, but I reside so I am also bonded to their rules. * Supplied accessories may differ in each country or areaĪfter reading many posts about 70D and Sigma 18-35mm having incosistent results I got disappointed, cause I also wanted to buy this lens to my 70D. Sigma 18-35mm F1.8 DC HSM specifications Date introducedĬanon EF, Nikon F, Pentax K, Sigma SA, Sony A The 18-35mm covers a modest 2x zoom range. The pictures below illustrate the focal length range from wide to telephoto (on Canon APS-C, 1.6x). Initially available in Canon EF, Nikon F and Sigma SA mounts Pentax K and Sony Alpha to follow.Ring-type ultrasonic focus motor with full-time manual override.18-35mm focal length (approx 28-50mm equivalent).But can an F1.8 zoom really deliver good results? Let's find out. Overall the 18-35mm F1.8 is a really intriguing product, and we applaud Sigma for pushing the boundaries of lens design ahead of the more conservative camera manufacturers. Crucially, at a street price of around $800 / £650 at the time of writing, for existing APS-C shooters it's an awful lot cheaper than buying a 24-70mm F2.8 and a full frame SLR to go with it. So while it may not quite match the capabilities of a 24-70mm F2.8 on a full frame SLR, for existing APS-C users it should offer something very close. The lens's 27-53mm equivalent focal length range is obviously a little limited, but should still be rather useful for such applications as wedding and events photography. It also incorporates several of the thoughtful design touches that we were impressed by on the 35mm F1.4, including an improved AF switch, and a large grip area on the base of the barrel for better handling. It's compatible with Sigma's new USB dock which allows you to fine-tune autofocus behaviour in much more detail than the AF microadjust corrections found on SLRs, which should help get the best possible focus accuracy and make the most of the large aperture. Essentially it means that APS-C shooters will be able to use lower ISOs when shooting wide open in low light and get similar levels of image noise, substantially negating one of the key advantages of switching to full frame.Īs we'd expect at this level, the lens uses an ultrasonic autofocus motor for fast, silent focusing. This is important as it's a major determinant of image quality. By this we mean that it will be able to project an image that's just over twice as bright onto a sensor that's slightly less than half the area, meaning the same total amount of light is used to capture the image. What's more, combined with an APS-C sensor, the system will also offer effectively the same light-gathering capability as an F2.8 lens on full frame. Sigma's choice of F1.8 as maximum aperture isn't a coincidence it means that the lens will offer the same control over depth of field as an F2.8 zoom does on full frame. This all bodes well for the company's latest offering - the record-breaking 18-35mm F1.8 DC HSM, which is the first constant F1.8 SLR zoom lens to hit the market. Most recently the 35mm F1.4 DG HSM impressed us with its exceptional optical quality at a very competitive price. The original (and recently-replaced) 30mm F1.4 EX DC HSM has long been one of our favourite lenses for APS-C SLRs, and the 50mm F1.4 EX DG HSM grabbed our attention back in 2008 due to its sharpness at large apertures. Over the past few years we've seen increasingly ambitious concepts appear from the company's design studios. This means it can no longer compete in the same way on price alone, and it's therefore switched its focus towards higher-value offerings. But this has changed over the part decade or so while other companies have shifted manufacturing to cheaper locations such as China and Thailand, Sigma has stubbornly refused to move from its factory in Aizu, Japan. In the film era it was best known for relatively inexpensive lenses that undercut the camera makers' own equivalents in terms of price. Sigma has a long history as a lens maker, having been founded over 50 years ago.
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