Physics limits how much depth of field any single photograph can contain. At 14mm f/11, the hyperfocal distance on the Sony A7RV is approximately 1.8 metres — meaning everything from 0.9 metres to infinity appears acceptably sharp. But "acceptably sharp" at 61 megapixels is not the same as "critically sharp." A foreground rock at 50cm from the lens will be visibly soft at 100% when shot at hyperfocal distance. Focus stacking solves this entirely.
The Technique — Two Frames is Usually Enough
For most landscape scenes with a near foreground element, two frames solve the problem: one focused on the foreground subject, one focused at or near infinity for the background. Mount the Sony A7RV on a sturdy tripod. Compose your shot. Take frame one focused on your closest foreground element — use magnified live view and manual focus. Without touching the tripod or composition, refocus at infinity and take frame two. That's your stack.
Blending in Photoshop
Open both RAW files and process them identically in Lightroom — same exposure, white balance, and tone curve. Export as 16-bit TIFFs. In Photoshop, load both as layers: File → Scripts → Load Files Into Stack. With both layers selected, go to Edit → Auto-Align Layers (Auto projection). Once aligned, go to Edit → Auto-Blend Layers → Stack Images, tick Seamless Tones and Colours. Photoshop's focus detection algorithm creates a blend mask that uses the sharpest region from each frame. Flatten and export.
When You Need Three or More Frames
Extreme macro foreground elements — a flower or rock within 30cm of the lens at 14mm — may require a three-frame stack: foreground, mid-ground, infinity. The 14mm GM's minimum focus distance of 25cm means you can get genuinely extreme foreground elements in frame, but the depth of field at f/11 from that distance is only a few centimetres. Three frames, focused at 25cm, 60cm, and infinity, covers the full scene with critical sharpness.