سلام
رویوی SLR Gear
کد:
http://www.slrgear.com/reviews/showproduct.php/product/1236/cat/31
Conclusion
Depending on what you're looking for, the Sigma 24-70mm ƒ/2.8 is a good lens - especially if you're looking to save money. While it doesn't provide the same corner-to-corner sharpness wide open (and even stopped down, to some degree), it performs extremely well on sub-frame cameras, though the resulting effective focal length is of questionable usefulness (38-112mm Canon, 36-105mm others).
So, the lens has its issues when used wide open: pronounced corner softness and chromatic aberration in the corners, as well as intense corner shading. If you'll be using this lens stopped down, these issues are less of a concern, but if you need excellent performance in any of these areas at ƒ/2.8, you may want to invest in more expensive glass.
در دیافراگمهای باز (که اغلب خریداران, چنین لنزهایی را برای همان موضوع انتخاب میکنند) مشکل سافتنس و CA و ویگنتینگ در کناره ها وجود دارد!
به نظرم انتخاب تامرون 75-28 با قیمتی نصف قیمت این لنز شاید گزینه بهتری باشد (با توجه به اینکه کیفیت تصویر این دو لنز شبیه به هم ارزیابی شده).