A good handy guide for Divi image sizes.
- Full Width Edge To Edge: 1920×1080
- 1 column: 1080 x 608
- 3/4 column: 795 x 447
- 2/3 column: 700 x 394
- 1/2 column: 510 x 287
- 1/3 column: 320 x 181
- 1/4 column: 225 x 128
height should follow 16:9 if possible
height should follow 16:9 if possible