As is their wont this time of year, the Sloof Lirpa team have produced another blockbuster: this year it’s a camera that provides far greater Engineering Dynamic Range (EDR) than anything on the market today. DxO is currently reporting the best EDRs of a bit over 14 stops. The Sloof Lirpa BigPixel One (BP1) has about 2500 times that EDR in the red and blue raw channels, and even more than that in the green channel! That’s more than 25 stops of engineering dynamic range!
In order to make such a breakthrough, the designers of the BP1 have turned the megapixel wars on their collective head; the BP1 is a full frame (24x36mm) camera, with just one pixel. The sensor has 4000×6000 sensor elements, and a conventional Bayer Color Filter Array (CFA) with 6 million each red and blue pixels, and 12 million green ones. The firmware that creates the raw file averages all the pixels in each of the four channels, then averages the average of the two green channels, and writes the result onto the camera’s flash card, together with the metadata and a preview JPEG image. The data is digitized with 14 bits of precision prior to processing, and the resultant pixel is recorded as 32 bit unsigned integers in order to preserve the incredibly low noise floor.
Base ISO is 100, but the camera allows increasing the ISO setting to 250,000,000 in one-third stop increments. Most of that ISO range is implemented in the raw processing firmware.
Several remarkable improvements in camera operation stem from this design.
- Reduced raw file sizes. The BP1’s raw files consist mostly of metadata.
- Effectively infinite buffer. Although the BP1 can operate at up to 10 frames per second, it can write to the flash card at faster than that, so you’ll never fill up the buffer.
- No anti-aliasing filter, yet no false color.
- No demosaicing required. All the raw processing program has to do is subtract the black point (supplied in the form of unaveraged masked pixels) and convert to the working color space.
- Unlimited depth of field. Distance to the subject has virtually no effect on the image.
- Instant auto-focus. The camera does not wait for the lens to focus before operating the shutter.
- Single shot HDR photography is a snap.
There are some compatibility issues. Negotiations are underway with Adobe, Capture One, and other raw developer companies to extend their processing pipelines so that they can properly support the BP1’s bit depth. Sloop Lirpa will provide a utility to convert BP1 raw files to 32-bit floating point files compatible with most HDR programs. Lirpa Labs is working with automated camera platforms and with stitching software companies on ways to provide ultra-high DR panoramas.