#video #toread about #Alpha-Phoenix’s #precision 2-billion-frame-per-second #cameras
on 02025-10-18#Alpha-Phoenix #video of a laser pointer at 2 billion frames per second. With a single pixel, so he then scans it over the setup with a gimbal-mounted mirror, and repeats the experiment, hundreds of thousands of times (3000 times per second). “Every one of these pixels was recorded separately, as a 1×1 pixel video!” Integrated encoder feedback in the motors was the key. He geared the pitch servo down with a timing belt to get better angular resolution because Katić, Domitran, Horvatek, and Lagator wrote a paper saying timing belt transfer accuracy was fine for angle metrology applications. “After figuring out which LLM code snippets were useful and which LLM code snippets were the reason I’d been frustrated for hours...” His optics train is one lens and one pinhole and, I assume, one photodiode. No, holy fuck, it’s a photomultiplier tube. His data acquisition rig is a benchtop 2Gsps oscilloscope, a Siglent SDS824X HD, 200MHz, 12 bits. He points out that the analog signal path amounts to a 58-frame delay line. To include the synchronization signal on the same line (because the scope can only do 2Gsps on one channel), he used a 500ns coax delay line from the laser. #precision #optics #cameras
on 02025-10-17computational #photography #DSP on new iPhone #cameras screwing up photo quality badly in some cases; explanation of things like dynamic range, diffraction, etc., with lots of comparison photos
on 02023-02-01apparently iPhone #cameras are better than currently available webcams
on 02021-01-22“FlatCam: Thin, Bare-Sensor Cameras using Coded Aperture and Computation” FlatCam is a thin form-factor lensless camera that consists of a coded mask placed on top of a bare, conventional sensor array. Unlike a traditional, lens-based camera where an image of the scene is directly recorded on the sensor pixels, each pixel in FlatCam records a linear combination of light from multiple scene elements. A computational algorithm is then used to demultiplex the recorded measurements and reconstruct an image of the scene. FlatCam is an instance of a coded aperture imaging system; however, unlike the vast majority of related work, we place the coded mask extremely close to the image sensor that can enable a thin system. We employ a separable mask to ensure that both calibration and image reconstruction are scalable in terms of memory requirements and computational complexity. We demonstrate the potential of the FlatCam design using two prototypes: one at visible wavelengths and one at infrared wavelengths. #DSP #hardware #sensors #cameras #compressed-sensing
on 02015-12-08