100 Megapixels coming to a Sony A7R VI ?
Related: diffraction, digital sensor, field curvature, Fujifilm, Fujifilm medium format, medium format, optical focus shift, Sony, Sony A7R, Sony A7R II, Sony A7R III, Sony A7R IV, Sony A7R V, Sony mirrorless
re: Sony’s New 19200 X 12800 = 247-Megapixel Sensor IMX811-AAQR Implies 108 Megapixels for 35mm Format
Very interesting sensor developments! Sony has recently announced 2.9 micron photosite sensors also.
NewShooter: Blackmagic Design URSA Cine & URSA Cine 17K
The 17K (17520 X 8040) camera with its 50.8 X 23.3mm 141-megapixel 17520 X 8040 sensor with its 2.18:1 aspect ratio may find a home only in high-end video cameras, but it would make an incredible mirrorless wide-aspect-ratio camera too. Then again 17520 X 13140 would be better, with a 4:3 aspect ratio. It appears that one of the 17K camera mounts uses the Hasselblad XCD mount.
The Blackmagic Design URSA Cine 12K Camera at only $14995 has a new sensor that might be appropriate for a Sony A7R VI. Or at least a sensor using similar tech. As it stands the sensor is most appropriate for video (eg a low pass filter and other features), and is RGBW so it’s not ideal for a still camera.
That said, the core technology for a 100-megapixel 35mm format camera is now in production. Or soon will be. The sensor is just a little bit cropped from the usual 35.7 X 23.8mm (eg Sony A7R V) but perfectly fine.
- 35.63 x 23.32mm
- RGBW (NOT a Bayer sensor)
- 12288 X 8040 resolution = 98.8 megapixels
- 2.90 micron pixel pitch (1.3X smaller than Sony A7R V or Fujifilm GFX100 II)
- Claimed 16 stops of dynamic range.
The sensor is “BlackMagic designed” but I’m guessing it’s fabbed by Sony.
100 megapixels for 35mm format, 170MP for medium format
The pixel pitch of 2.90 microns is a factor of 1.30X vs the 3.76 microns of Sony A7R V and Fujifilm GFX100 II. This is hard core, equating to 172 line pairs per mm. Contemplate that vs the 40 lp/mm MTF charts still in popular usage.
The pixel pitch of both the 17K and 12K sensors imply a future ~170-megapixel Fujifilm GFX100 III or Hasselblad X3D 170-C.
Sure would be nice to see Sony enter the medium format game to keep Fujifilm alert and aggressive.
At a time when Nikon and Canon remain at ~45 megapixels and the 60MP Leica SL3 has only just debuted*, can we say game-over if Sony moves quickly and before the others?
* Presumably, Leica would promptly follow suit with a Leica SL4 by 2028 or so. And who knows about Nikon or Canon.
Image quality
The extra pixels are much more about total image quality than resolution. About eliminating digital artifacts like moiré and staircasing and spurious detail, at least with most lenses and by f/5.6. About smoother/cleaner edges and tonal transitions.
Sharpness gains on a 100MP will be minimal and not just from lenses. Two factors are at loggerheads with respect to gains in sharpness on a 100MP 35mm-format sensor. A squeeze from both ends.
Pixel pitch vs depth of field
The 2.9 micron pixel pitch means requires about 2/3 stop more in terms of depth of field eg f/10 instead of f/8. In practical terms, this is unworkable.
Even on the existing 60MP Sony A7R V f/8 is noticeably degrading micro contrast and resolution startingg, with the effects of f/10 much more severe. This is easy to see just by comparing f/5.6 to f/8 using a top-grade lens. Using f/10 on even tinier pixels will just look like mush even if the lens is the best available.
Pixel pitch vs diffraction
re: diffraction
Diffraction dulling at any specified aperture is the same regardless of sensor or format. However, the effects are relative to the size of the photosites. The smaller the photosites, the lower the micro contrast and the lower the resolving power. At some point this is de facto zero resolving power due to too-low contrast.
Diffraction with 2.9 micron pixels occur 2/3 of a stop earlier eg f/6.3 instead of f/8. Using f/8 on a 100MP sensor will not produce more detail than with a 60MP sensor with its 3.76 micro pixels. You will be forced to use f/6.3 and that is right on the edge of tolerable.
And that’s assuming a world class lens, the very best.
Below, diffraction spot size (Airy Disc diameter) relative to the photosite size of the sensor demands less and less stopping-down to minimize the blur effect relative to the photosite. On a 100MP sensor (35mm format), an f-stop of f/4.5 is needed for similar per-pixel blur effects as with f/5.6 on a 60MP sensor.
Practical gains in detail?
Those two challenges leave negligible room for resolution gains except of with very thin DoF requirements. And if sharpness is desired outside a small area, the lens had better have nil field curvature and negligible focus shift.
Yet serious performance problems from those two factors are readily and obviously seen in a laughably poor performance with $5K top-of-the-line lenses like the Leica 75mm f/2 APO-Summicron-SL ASPH.
