Sony Breaks New Focal Length Ground in Professional Video--and No One Notices

On February 3, 2016, Sony announced a new camera, three new lenses, and two teleconverters. 媒体对这款新产品的规格大肆报道 索尼a6300无反光镜相机, and with reason, but they all skipped over the big announcement. For live producers, the big news only partially concerns one of the three new lenses, the 24-70 f/2.8克咖啡; 70-200 f/2.8克铁，以及85mm f/1.4 GM FE, that are the initial offerings in Sony’s new line of G Master lenses (下面的图1).

图1. 索尼A6300和新的通用FE镜头

For the photographic press, the a6300 and the new faster GM lenses are the main story. But as a professional video producer who has been enjoying the benefits of filming on Sony’s Super35 sensor professional video cameras since Sony introduced the FS100 in 2010, 索尼新推出的e-mount变焦镜头, 配对时 索尼的新FS5 (下面的图2)，是没有被谈论的大故事. This new combination has allowed Sony to break the telephoto barrier that was stuck for the longest time at the equivalent telephoto range of a 10x zoom camcorder. 拍摄野生动物的专业视频制作人, 会议, 许多现场活动需要更大的长焦范围, and this is a big reason many have had to maintain professional camcorders alongside their Super35 interchangeable-lens video cameras.

图2. 索尼PXW-FS5

突破240mm屏障

当索尼推出电子卡口镜头系列时, the company’s engineers weren't sure how they would design a zoom lens that would have a focal length beyond 200mm and even lenses that were faster than f/4. Last year they broke the 200mm barrier by a paltry 20% with the Sony FE 24-240mm f/3.5-5.6个镜头 and today they broke the f/4 barrier with a pair of f/2.8个变焦镜头.

Video professionals who use the professional line of Sony video cameras--the FS100, FS700, FS7, and FS5--require lenses with a constant aperture; otherwise the iris closes while you zoom in. Granted, Sony e-mount lenses have a trick up their sleeves that Canon and Nikon SLR lenses do not. Because Sony uses an electronic iris on their e-mount lenses, 当放大到最宽焦距时, if you first stop-down a variable-aperture lens to at least the smallest aperture in the lens’ variable range (f/5.6适用于24-240mm以上镜头), 当你放大时, 镜头在整个变焦范围内保持光圈. When using this technique, the variable-aperture 24-240mm f/3.5-5.6镜头可以像恒定光圈24-240mm f/5一样工作.6个镜头.

我知道, 20% extra telephoto zoom range with a loss of an entire stop of light sensitivity isn’t that exciting. 但请记住，在相同的f/5下.6级透光, Sony just demolished their new 240mm barrier to an incredible 1200mm, enabling true long-lens work on Sony Super35 video cameras for the first time. 这也意味着在某些情况下, video producers can finally ditch their traditional small-sensor camcorders with fixed lenses.

焦距说明

Even the Sony professional camcorder with the most modest camcorder zoom lens, 1英寸传感器索尼X70 (下面的图3)，有12倍变焦. This translates into a longest full-frame equivalent (FFE) focal length of 348mm. By comparison, a 200mm lens on a Super35 sensor camera, which has a 1.5倍作物因数, 最大可达300mm (FFE), 这是一台10倍摄像机通常能提供的效果吗, 这在远摄端是不够的. Every camcorder has a slightly different FFE at its widest zoom but the ones I will discuss here are between 26-28.8mm.

图3. 索尼PXW-X70

The $2,800 1/3" sensor Sony NX3/1 has a 20x zoom lens that has an FFE of 28.8- 5776毫米，索尼X160(3,749美元)和 X180 ($3,995) both have the same 1/3” sensors and a FFE of 26-650mm on their 25x lenses. 我认为大多数工作都是这样, a 25x zoom range provides enough zoom to film a presenter from the back of even the largest of conference rooms. But if you already own (or desire to own) a large-sensor video camera like the Sony FS5, because of the creative opportunities it affords with a wider exposure latitude thanks to SLOG3 and a shallow depth of field thanks to its larger Super35 sensor, then you’ll be excited to hear that now you can have your zoom and keep your large sensor too.