The 5-axis in-body stabilization system is the same one used on the S1 and S1R, but how does it work for video? I found that it let me shoot natural-looking static handheld video, with a bit of bobbing and weaving à la Law and Order. Should you attempt anything more ambitious like a tracking shot, you'll get sharp jolts that will make your viewers queasy, unless you're much steadier than I. IBS is no substitute for a gimbal, after all, but it'll serve in a pinch if you forget your tripod.
The S1H has the same superb 5.76-million-dot electronic viewfinder (EVF) that impressed me on the last two models. It's better than an optical viewfinder for video, because I saw exactly what I recorded, including exposure, white balance and focus. With a 120 FPS refresh rate and .005 seconds of lag, it was supremely fast and ultra-clear.
The most noticeable change between the S1/S1R and S1H is the fully articulating rear display, which probably accounts for the extra weight. Panasonic has done a new trick here: Not only does it flip out and rotate around like the display on the GH5, it also tilts up. "The combination of a tilting and swivel mechanism makes unusual compositions and creative angle shots easy to frame," Panasonic said in the S1H brochure. In the real world, I didn't quite see the benefit, other than making it a bit faster to shoot at a low angle.
Combined with the IBS (in-body stabilization), this will make the S1H the ultimate vlogging camera if you can handle the weight. More importantly (for me anyway), it made it easier to film myself for "standup" on-camera chores when it's poised on a tripod.
Vlogging and run-and-gun shooting will also be aided by Panasonic's increasingly improved contrast-detect "depth from defocus" autofocus. Since the launch of the S1, Panasonic has made strides with this system, reducing the amount of focus "hunting" during video shooting. I found that while shooting different subjects and myself, it kept the focus locked down pretty darn well.
If you're taking photos, and you can do that nicely with this camera too, it can hit focus in 0.08 seconds, compared to 0.05 seconds for Sony's A7 III. You can shoot in bursts at 9 fps with AF fixed, and at 6 fps with continuous autofocus enabled. As before, the S1H supports AI autofocus tech that can detect humans and animals including birds, dogs and felines, both in video and photos modes. I didn't have any animals to shoot in LA, but with the S1, I found the system worked great for humans and dogs, not so much for chickens.
So how does the camera's focus system fare? It's still not as good as Canon's dual-pixel system, but it's getting pretty darn close. Due to the much larger sensor, it's a bit slower than the GH5's AF system. When it does miss focus, it's also a lot more noticeable due to the much shallower depth of field on the S1H. Overall, though, I felt comfortable shooting with this and would happily put it into service for any job, if I could afford it.
Low-light capability on this camera is much more impressive than the S1 and S1R. The S1H's 24.2-megapixel sensor is similar to the one on the S1, but it has some important new tweaks. It's the first full-frame model with Panasonic's Dual Native ISO system, also found on the Lumix GH5s. The base ISOs are now at ISO 640 and ISO 4,000, a boost over the GH5s (ISO 400 and 3,200).
Practically, I could shoot clean footage in very low light, up to about ISO 25,600, which is Sony A7 III territory. That'll give filmmakers without access to lights the ability to shoot great-looking footage under streetlights, in bars and even in moonlight.
Keeping in mind that I was playing with a pre-production model, footage from the S1H was impressively rich in daylight. The full-frame sensor gives an unbelievably cinematic look, especially with fast lenses like the new Lumix S Pro 28-70mm f/2.8 and 50mm f/1.4 models. Since it uses the entire sensor for both 6K and 4K (with downsampling for the latter), you get very crisp images with no sign of aliasing or other artifacts, thanks to a low-pass filter.