FILE "ElCapitan.bin" BINARY TRACK 01 MODE1/2048 INDEX 01 00:00:00 This method is complex and rarely needed. Most users should stick to the .iso from Option 1. After conversion, check the boot signature:
hdiutil convert ElCapitan.sparsebundle -format UDRW -o ElCapitan_raw.dmg Then use dd to extract raw data:
Mount the ISO in Finder (double-click) to ensure it contains /System , /Library , etc.