Lens, sensor and recording formats
The heart of any camcorder is of course its sensor, and its sensor is only as good as the lens.
Here, then, is where the compromises in the PXW-Z100, at least on paper, come to the fore.
The camcorder is based around a single CMOS chip. But it is not a large-sensor camcorder, or even a broadcast (2/3-inch) camcorder. Whereas the PMW-200 and PXW-200 have three half-inch chips, and Sony’s shoulder-mount broadcast cameras, three 2/3-inch chips, the PXW-Z100 has a single, 1/2.33-inch chip.
This, coupled with the need to cram 4K’s worth of pixels into a fairly small imager, may mean the camcorder is less dependable in low light than its HD cousins. It also means that film makers have only limited control over depth of field.
And, although the Z100 is arguably a “special use” camcorder, due to its 4K recording, it is not clear whether the Z100 meets the EBU requirements for broadcast, which demand at least three 1/3-inch chips. A producer pitching for network broadcast may want to play safe, and opt for a larger sensor or multi-chip camcorder.
The other consideration for professional broadcasters is Sony’s choice of lens. The lens on the Z100 is the company’s own G-series type, which is similar in design and appearance to the lenses on the NX5 and the PMW-150. These are not bad lenses by any means, but they lack the tactile feel of the Fujinon units used on the PMW-200 and PMW-300.
The G lens on the Z100 does have separate rings for aperture, focus and zoom, but these are all servo controlled rather than manual, and the lens lacks the attachment rings for controllers and the lens information scales of the higher-end camcorder units.
The Z100 offers a 20x zoom with professional controls
On the plus side, the lens is responsive, and offers a 20x zoom: useful additional reach over a PMW-200. With 4K filming, of course, it is possible to punch in further on the image in post, potentially allowing producers to position a Z100 away from the action – at the back of a room for example – knowing they can crop in for a close up in the edit, if need be.
In our tests, the G-series lens performed as would be expected, with no noticeable ghosting or flaring. The built-in image stabiliser is also effective, although for 4K filming, we would really recommend a study tripod.
When it comes to recording formats, the Z100 is, though, a veritable Swiss Army Knife, even without the planned AVCHD upgrade. These range from full (cine) 4K at 4096×2160 at 50p – for PAL regions – and up to 500mbps recording, QFHD, and down to HD at 113mbps. Note that there are no SD formats on this camera.
One point to keep in mind, is that the codecs currently supported on the Z100 are all high bitrate. This does impact on the camera’s recording time. We found in our tests that a 32GB XQD card ran to just under half an hour in 1080p, and around 18 minutes in QFHD.
Sony cites 15 minutes’ recording for full 4K with a 64GB card at 50p or 25 minutes for 25p, and lists other options on its camera specifications page. Whilst productions will benefit from the high bit rate and 4:2:2 colour, media costs are a consideration, especially when compared with the ability of cameras such as the GH4 to record 4K on low-cost SD cards.
But the real test of any camera is, of course, its image quality, so we put the Z100 through its paces in the field.
Next: Image quality and the Z100 in the field