DPRSplit Beta 0.8: File Splitter for Canon 5D Mark IV / Dual Pixel Raw files

What this application is for:

Canon 5D Mark IV's sensor has a somewhat unusual pixel arrangement: each pixel has a dual photodiode construction. Each photodiode is associated with a subpixel, and thus the pixel is split in two. If Dual Pixel RAW mode is enabled in the camera, the resulting CR2 file contains two images, or two frames: one composite, made from reading both subpixels, summed; and the other is made out of one set of subpixels. In other words, a pixel is composed of two subpixels, let’s call them A and B. The first frame in a CR2 file is made of “A+B”, while the second is made from “B” subpixels only.

Canon Dual Pixel example

The screenshot above shows two frames of one such shot taken in Dual Pixel RAW mode, extracted via DPRSplit, and processed in Adobe Camera Raw 10.1 (with all sliders set to zero), and further opened in Photoshop

Left: the “B” frame – all of the highlights are preserved. Right: the “A+B” frame, the sky and some areas of the mountain are featureless and blown out.

The intended use of this arrangement is to enable some extra editing after the shot: because of the parallax between the subpixels, Canon Digital Photo Professional software allows one to preform microadjustment of focus, bokeh shift, and ghosting reduction.

However, there is one more possible use for a dual-pixel raw, which is not covered by the manufacturer: the second frame, the one that is made out of only “B” pixels, collects half of the light that the composite frame does, as if it was exposed one stop lower compared to the composite frame. In essence, in Dual Pixel Raw mode, the camera records into one file some equivalent of two shots, bracketed by (approximately) 1 EV.

DPRSplit Beta 0.8

The DPRSplit application allows one to:

  • Extract the second (1 EV down) frame or both frames from Dual Pixel RAW CR2 files;
  • And save the extracted frames as DNG files.

Resulting DNG files can then be opened and processed in (practically) any raw converter featuring DNG support.

System Requirements

  • OS and CPU
  • Windows *: Windows 7 – Windows 10, 64-bit
  • Mac OX: Mac OS X/macOS 10.6-10.13, 64-bit processor (so, all Intel Macs, except for some models from 2005-06 with Core Solo and Core Duo processors)
  • Screen resolution no less than 1600x900
  • 50MB of disk space for the application

 

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