Fisheye Lenses For 360 Video
The choice of lens for a 360 video camera rig is an important step in the process of creating a quality final product. Making the correct choice for the shot can save time and money in post, making the job of stitching easier.
Fisheye lenses offer a number of significant advantages over traditional wide angle lenses for 360 video production, the details of which can be found below.
We have standardised on 2 main fisheye setups for 360 video production:
GoPro Hero 4 Black Edition cameras with Izugar MKX-19 lenses
Sony A7S Mark II cameras with Samyang 8mm f/2.8 UMC II lenses
The Izugar fisheye lenses are specifically designed for 360 video production and are a replacement for the standard wide angle lenses of GoPro cameras. Installation is very simple, taking around 5-10 minutes per lens.
The main advantage of fisheye lenses is the increased field of view compared to traditional lenses. The Izugar MKX-19 lenses offer 194 ° field of view (FOV) meaning they can actually see behind themselves. This gives an incredibly wide view, which has a number of benefits.
Due to the increased FOV, less cameras are needed to achieve a full 360 image. As little as 2 GoPro cameras back to back fitted with Izugar lenses can be used to capture a fully spherical 360 video. This is ideal for tight spaces, where the smaller physical distance between the cameras means parallax is reduced, improving stitch quality. Less time is required for camera setup on set and this also means less data to deal with in post which saves time and money.
Another benefit of the increased field of view is that the overlap between cameras is greatly increased compared to a traditional wide angle lens. This means that there is greater image redundancy between cameras making it easier to find common points to stitch the videos together. The overlap allows the ability to mask objects moving between cameras via rotoscoping methods, meaning they don’t appear to pass through seams/tears in the footage.
The minimum working distance can also be reduced when using fisheye lenses, meaning objects can be closer to the camera without the risk of being in a stitch line, however parallax can still a major issue here.
There are however several tradeoffs to using fisheye lenses. Firstly, fisheye optics are inherently difficult to design and manufacture meaning that sharpness and chromatic aberrations are often worse than traditional lenses, particularly in the corners of the image.
Another disadvantage is the reduction in final output resolution. This is due to the wider field of view, where 1 camera covers the same area as multiple cameras. For example, 1x4K with a fisheye vs 4x4K with normal lenses:
All the factors above should be taken into consideration before deciding upon which lens will be suitable for a shoot. Here at M7Virtual we carry a mixture of rigs with us on set allowing us to choose the best rig on a shot by shot basis.