Dual Pixel RAW Microadjustment: RF 50mm f/1.2L and the R5
Dual Pixel RAW is a Canon capture mode that records each pixel’s left and right photodiode data separately, storing approximately twice the file size of a standard RAW. The primary advertised use — bokeh shift, ghost reduction — is marginal in most practical situations. The genuinely useful application is microadjustment of the focus point in Canon’s Digital Photo Professional software after capture.
At f/1.2 on the RF 50mm, the depth of field is thin enough that a focus acquisition that lands two millimeters in front of the intended plane produces a noticeably soft result. Eye AF is accurate but not infallible. Dual Pixel RAW microadjustment allows a post-capture shift of the apparent focus point by a fraction of the captured depth of field — effectively moving the sharpest plane forward or backward within the image after the exposure is made.
The range of adjustment is not large. It cannot rescue a frame that missed focus by a centimeter. It can rescue a frame where autofocus landed on the eyelashes rather than the iris, or where the subject moved imperceptibly during AF confirmation. In practical terms, it converts a soft-but-close miss into a usable frame a portion of the time.
The workflow: shoot in Dual Pixel RAW mode (set in the RAW quality menu), open the file in Canon’s Digital Photo Professional 4 or later, select Dual Pixel RAW Optimizer, and use the microadjustment slider under Depth-of-field priority. The software renders a preview as you adjust. When the focal plane lands where you intended it, export.
The cost is file size — Dual Pixel RAW files are roughly 40 megabytes each versus 24 for standard CR3 on the R5. For a full session at 30fps burst, this is impractical. For a portrait session with controlled shooting pace, the insurance value is real.
The lens that makes this worth doing is the lens with the shallowest depth of field at shooting aperture. The RF 50mm f/1.2L is that lens.