I had heard some folks tout the iPhone 12 Pro for it's incredible night shots (a special mode that basically does a long exposure). So decided to see just what it could do.
I could have done a better job in framing. But I did try to to match things up as close as possible:
EOS 5D IV with an EF 50mm f/1.2L at f/2, Tripod. RAW.
iPhone 12 Pro in telephoto mode (seen both 52mm and 56mm as the full-frame equiv; I think the 52 is wrong though). Tripod. RAW. No manual mode though and it was a bit trial and error to get it to do a specific shutter duration.
First pair of images is for a 20 second exposure. where basement lights over my photography area were off and just some distant ones on. I estimate the light in the scene to be -2 EV. 5D was at ISO 200. Lightroom was confused by the iPhone RAW file, but it claimed ISO 2500.
iPhone 12 Pro
Second pair of images is for a 30 second exposure where all basements lights off. Just some afternoon light (quite dim) coming in from far-away windows. Estimate the light in the scene was -6 2/3 EV. 5D was at ISO 3200. iPhone RAW file showed ISO 6400. But again, Lightroom was confused with the file and other metadata wasn't right.
iPhone 12 Pro
Not surprisingly, the 5D crushes the iPhone 🙂
Also, with the f/1.2 lens, I could have gone down to that aperture and since ISO 6400 is still quite clean, I could have captured an image in a -9 EV scene.
Finally, the images were reduced to have a vertical height of 768 pixels. Of course from the original 30 MP capture, that is going to lead to more noise-reduction due to the greater downsizing as compared to the iPhone's 12 MP capture.
Thus, here are two portions of the 30-second exposure images at 100%. I really cropped the 5D image to keep the file size small for upload here.
iPhone 12 Pro (30 s exposure; 100% zoom crop)
5D IV (30 s exposure; 100% zoom crop)
Oh... absolutely no editing done; not even any lens corrections for the 50mm f/1.2.
White balance is off; tried to get it within the ballpark on the 5D. Approx 4000 K for the 20 s shot and 5500 K for the 30s shot (though I should have gone around 6000 or so).