|Yellowstone with a Sony a7s II|
Celebrating the 100 year anniversary of the National Park Service at the end of August, 2016, I returned to Yellowstone with a Sony a7s II in-hand. The still photos and video above were shot using a Metabones Speedbooster EF adapter and Canon 100-400mm zoom with 1.4x extender, and a Rokinon 50mm cine lens.
First thoughts: despite the fantastic advances of the mirrorless and light sensitive sensor of the a7s, the autofocus capabilities of this camera are far, far behind Canon, making it essentially unusable for the needs of wildlife. All of the stills here were shot manual focus and attempts with autofocus were quickly abandoned due to seemingly endless focus racking and its inability to hit any kind of focus within a reasonable amount of time. [Note: I also have a 50mm Sony prime and it doesn’t focus any better with that lens than Canon lenses on the Metabones Speedbooster. The lens adapter does not seem to be what’s holding autofocus back].
The full size sensor and light sensitivity are well-known delights. Otherwise, having the ability to over-crank the frame rate within this price range and small production footprint is really, really, really great. Though the 120 fps setting uses a cropped version of the sensor (punching in like a APS-C DSLR), the resulting image quality is still fairly good and worthwhile.
The downside of the sensor’s amazing light sensitivity is the large amount of ND filtration needed for shooting in outdoor daylight. I’m still adjusting to shooting Sony S-LOG3, which performs best at a slight overexposure of 1-2 stops. It’s easy to overexpose during the fast timing needs of wildlife. The next time I shoot with this camera I’ll use a Pix 5 recorder/monitor with a histogram and scopes that are applied to an S-Log3 LUT version of the image so you can see what the exposure will actually be without the guess work.
The aforementioned autofocus for still photography
Adobe Premiere doesn’t recognize the higher frame rate within the MP4 wrappers and the speed of the over-cranked clips need to be manually entered by revising the clip speed (Top Nav/Clip/Speed Duration) as a percentage adjustment (25% for 120fps, for a 30p sequence, 50% for 59.94 fps, etc.).
Resolve doesn’t recognize MP4s and media for color correction needs to be transcoded to ProRes (or other) for coloring.