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.

Hyperfocal distance is the closest focus distance at which depth of field extends to infinity. Focus the lens there, and everything from half that distance to the horizon is acceptably sharp. It is a foundational landscape technique, and it is where the Sigma 35mm f/1.4 DG DN Art produces its most argument-ending results. At f/8 on a full-frame sensor, the hyperfocal distance for a 35mm lens is approximately 4.6 meters using a 0.

Every lens on every sensor has a diffraction limit — the aperture beyond which stopping down no longer increases sharpness but instead decreases it. Light diffracts around the aperture blades, spreading the point spread function across adjacent pixels. On a high-resolution sensor like the R5’s 45-megapixel chip, diffraction becomes measurable at around f/11 and visible at f/16. By f/22, you have traded resolution for depth of field at a poor exchange rate.

When photographers talk about a lens being “sharp,” they are usually compressing a surprisingly complex optical conversation into a single casual word. Sharpness is not one thing. It is a mix of contrast, fine-detail rendering, microcontrast, aberration control, field consistency, and how well a lens holds its performance from the center of the frame to the outer image circle. That is why lens engineers lean on Modulation Transfer Function, or MTF, charts.