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I do think the HQ camera is due an upgrade, though I'd prefer a proper low-light camera, ideally Sony Starvis. Although you can buy cheap Starvis modules you d

I do think the HQ camera is due an upgrade, though I'd prefer a proper low-light camera, ideally Sony Starvis. Although you can buy cheap Starvis modules you don't have full control over the exposure time and/or can only shoot in a compressed format. The HQ camera is well-supported with good drivers, like all Raspberry Pi hardware, which is why people still use the HQ Camera for cheap astronomy projects despite having a small sensor and poor low-light performance.

dheera 3y ago
Full frame cameras typically perform better than "low light" cameras with small sensors. Everything else equal, bigger collection area trumps everything else, simply because more photons means better SNR under shot noise assumptions. SNR of a pixel scales with sqrt(average number of photons collected). When your full frame sensor has 25X the physical area as a small sensor, that's hard to beat. You can't easily get a 25X increase in number of photons collected on the smaller sensor. There are only so many photons that hit it. You can engineer the hell out of the silicon, but the fill factor multiplied by quantum efficiency of the sensors is already much higher than 1/25 so there is no theoretical room for a 25X improvement even under ideal assumptions. You can increase the number of photons that hit it with bigger, larger aperture lenses, but beyond f/2.0 or so you start hitting limits with our current optical technology in correcting chromatic aberration and other issues, and it will take miracles to get a 25X improvement on the latest state-of-the-art optics. Sony's full frame sensors also have the same back-illuminated design as their Starvis-branded sensors, by the way, so that part is not unique to Starvis.
- teamonkey 3y ago
  In general, yes, but there are good reasons not to use a full frame sensor. They’re big, they run hot and they’re expensive. You’re looking at 10x the price range of the HQ cam. And one trouble with big pixels is that it means low pixel density. If you take an IMX585 astronomy camera it will produce a better quality image than any used or new DSLR in the same price range, despite having pixels a fraction of the size. The (considerable) negative side is the smaller frame.

dheera 3y ago

Full frame cameras typically perform better than "low light" cameras with small sensors. Everything else equal, bigger collection area trumps everything else, simply because more photons means better SNR under shot noise assumptions. SNR of a pixel scales with sqrt(average number of photons collected). When your full frame sensor has 25X the physical area as a small sensor, that's hard to beat. You can't easily get a 25X increase in number of photons collected on the smaller sensor. There are only so many photons that hit it. You can engineer the hell out of the silicon, but the fill factor multiplied by quantum efficiency of the sensors is already much higher than 1/25 so there is no theoretical room for a 25X improvement even under ideal assumptions. You can increase the number of photons that hit it with bigger, larger aperture lenses, but beyond f/2.0 or so you start hitting limits with our current optical technology in correcting chromatic aberration and other issues, and it will take miracles to get a 25X improvement on the latest state-of-the-art optics. Sony's full frame sensors also have the same back-illuminated design as their Starvis-branded sensors, by the way, so that part is not unique to Starvis.

teamonkey 3y ago
In general, yes, but there are good reasons not to use a full frame sensor. They’re big, they run hot and they’re expensive. You’re looking at 10x the price range of the HQ cam. And one trouble with big pixels is that it means low pixel density. If you take an IMX585 astronomy camera it will produce a better quality image than any used or new DSLR in the same price range, despite having pixels a fraction of the size. The (considerable) negative side is the smaller frame.