Complex sentence: Many manufacturers make filters labeled as 81B with transmission curves which are similar, but not identical, to the Kodak Wratten 81B, according to that manufacturer's idea of how exactly it is best to warm a scene, and depending on their manufacturing techniques.
Split into simpler sentences: Many manufacturers make filters labeled as 81B with transmission curves which are similar, but not identical, to the Kodak Wratten 81B. This is according to that manufacturer's idea of how best to warm a scene, and depending on their manufacturing techniques.