We have two databases those two databases each database size 700 Gb, 1<sup>st</sup> database is full recovery model and 2<sup>nd</sup> database bulk-logged recovery model.
1<sup>st</sup> database having 20% of database fragmentation and 2<sup>nd</sup> database having 80% of fragmentation,
We are rebuilding the both database, after rebuild database we take the log backup of both database.
Those two database log backup size comes to same or if any different based on database recovery model.