The lens of the world’s largest digital camera was introduced to the world around this time last year. Now the sensor has been completed as well, and Stanford researchers have taken the first 3,200-megapixel images in the lab. Yeah, you read that well – 3,200 megapixels, and these are the largest photos ever taken in a single shot.
Scientists at the Department of Energy’s SLAC National Accelerator Laboratory assembled the sensor from 189 individual 16-megapixel sensors. In fact, these individual sensors are similar to those that we have in our DSLR and mirrorless cameras, only they’re more sophisticated. Completing the focal plane took six “nerve-wracking months.” The SLAC team inserted 25 rafts into their slots in the grid, and the gaps between sensors are only around five human hairs wide, even less. “Since the imaging sensors easily crack if they touch each other, this made the whole operation very tricky,” SLAC explains. But it wasn’t just tricky, it was expensive too – one raft costs up to $3 million.
If you’re having a hard time imagining how huge the photos taken with this camera will be, SLAC gives you a reference: it would take 378 4K ultra-high-definition TV screens to display one of them in full size. “Their resolution is so high that you could see a golf ball from about 15 miles away,” SLAC adds. Now imagine what a camera like this can do for astronomy.
Since the camera hasn’t been fully assembled yet, the researchers tested the sensor using a 150-micron pinhole to project images onto the focal plane. The first photo they took was a head of Romanesco – a weirdly beautiful type of broccoli, but they tested the sensor on other objects as well. Of course, it would be impossible to add gigantic images here. But SLAC has shared their test shots in this blog post so you can explore them in more detail.
“Taking these images is a major accomplishment,” said SLAC’s Aaron Roodman, the scientist responsible for the assembly and testing of the LSST Camera. “With the tight specifications we really pushed the limits of what’s possible to take advantage of every square millimeter of the focal plane and maximize the science we can do with it.”
The camera is expected to be fully assembled around mid-2021. It will then be installed at Rubin Observatory in Chile, where it will shoot panoramic images of the complete Southern sky. Over the following ten years, the camera will take one panorama every few nights and help astronomers explore the dark matter, dark energy, and our ever-changing skies.