A bracket is a set of photos of the same view taken at different brightness levels: one dark, one normal, one bright, and so on. Merging them gives you a photo where both the bright windows and the dark corners look right. See HDR merge.
Automatic grouping
When you upload, CasaVivid reads each photo's camera details and groups shots into brackets on the HDR-Brackets tab. Shots are grouped when they were:
- taken in quick succession, with no more than about 3 seconds between one shot ending and the next starting;
- taken at the same aperture and ISO, except on phones (see below);
- at least slightly different in brightness. Identical exports of one shot don't count as a bracket.
Photos without capture-time details in the file can't be grouped automatically.
Fixing a grouping by hand
Shots that didn't fit a group appear under Unbracketed exposures.
- Click the shots that belong together to select them.
- Click New bracket from 3 (the number is how many you selected). You need at least 2 shots.
- To add shots to an existing bracket instead, select them, open the bracket and click its Add button.
iPhone and other phones
Phones bracket by changing ISO rather than shutter speed. CasaVivid allows for this, so bracketed HEIC or JPEG shots from an iPhone group the same way camera brackets do.
RAW and JPEG of the same shot
If your camera saved both a RAW and a JPEG for each shot, only the RAW is used in the merge.
How many shots are used
A merge uses up to 7 shots per bracket. 3 to 5 shots, about 2 stops apart, work well for most rooms.