2013 PDN PhotoPlus Sony Round-up
Part I : The New Sony a7r Camera
The new Sony A7R camera is angular and represents a new direction for Sony's industrial camera design. It eschews the minimalist svelteness of the RX-1 and RX-100 cameras in favor of greater emphasis on ergonomics and control, such as those found on the a-series SLT cameras. Yet the sharp angles are also in contrast to the curves of the a99, a77 and other SLT cameras.
Surprisingly, when the camera was announced it was not revealed to be a part of the popular NEX series of interchangeable lens E-mount cameras. It is physically quite different from the NEX cameras - compactness is not the main focus. Sony seems to be re-positioning the "A" series of cameras. First they released the [odd] a3000 budget e-mount camera in SLR form factor. Then when most expected the full frame NEX-7 style camera (possibly named NEX-9), they kept everyone on their toes and revealed the a7 / a7r cameras in a wildly different form.
I was told by Mark Weir, senior technology manager at Sony Digital Imaging, that the Sony a7 uses the 24 megapixel sensor released a year ago in the a99 and RX-1 / RX-1r camera bodies. It is also, purportedly, in the Nikon d600. Thus the image quality performance should be similar to those cameras (potential vignetting or corner sharpness issues related to the e-mount notwithstanding). The a99 and RX-1 cameras should be good "control" cameras for comparison when testing the aforementioned corner issues.
The a7r uses a newly developed 36mp sensor. Mark Weir credited the superior video image quality of the a7r versus the a7 despite the higher resolution (necessitating greater downsampling) to the new sensor. This a7r sensor features an optimized microlens design as well as, "curved fields" to compensate for the size of the E-mount opening. A spokesperson at the Sony booth on the show floor said that the curved fields allow for the full frame image to be captured. Additionally, it is due to these curved fields that in-body image stabilization (aka IBIS) is impossible. He described it stating that the position of the sensor must be absolute or else the full frame image cannot be captured (because the E-mount hole is so small). Thus, the sensor cannot be shifted for stabilization. This probably rules out the rumored (see Sonyalpharumors.com) z-shift axis for autofocusing with manual focus lenses via a sensor that moves back and forth. Hopefully z-shifting can be used for the rumored hybrid A-E mount camera since the sensor will not be shifting while in operation (although the a-mount IBIS function will most likely be disabled when in E-mount mode).
Sony a7r (photo sample)
While I was testing the Zeiss Touit 12mm lens on the Sony a7r (while waiting for the Otus lens), the Sony rep told me that the Touit lens covered the full frame and that it goes to show you how large the image circle from some APS-C lenses can be. While reviewing the images on the rear LCD of the camera I was surprised to see that there was no [shockingly] vignetting whatsoever. When I imported the photos however, I realized the camera was in APS-C mode (the image resolution is 4800 x 3200 pixels or 15.36 megapixels). The photos the lens produces (despite only covering an aps-c area) look great and 15MP isn't bad, depending on one's usage. For events or for capturing for web usage, it should be sufficient for most users.
With the Zeiss Otus 55mm lens on the Sony a7r, the camera produces full frame images at a resolution of 7,360 x 4,912 pixels or 36.15 megapixels. By comparison, the 24 megapixel Sony a99 produces image files at a resolution of 6000 x 4000 pixels. Although it sounds like 36 megapixels will produce 50% higher resolution (vs 24MP) the reality of a 50% increase in megapixels is an approximate 23% increase in resolution of the files.
The feel and construction of the Otus lens gives a great first impression. This lens feels like it can withstand serious abuse. The focus ring is SLR perfection. The movement is velvety smooth and has a wide amount of rotation for precise focus pulling. Focusing at 1.4 isn't easy but focus peaking and focus magnification help immensely. When I tested the Otus on a 5d3 with different (but equally bad) lighting, the photos did exhibit some [surprisingly] chromatic aberration wide open. This second test on the a7r displayed no CA.