You don’t need lin button in Flame or any other software to do a math operation in linear light if you’re in 2.2 gamma encoded space. Just need to reduce the gamma to 0.4545 (1/2.2) before the critical operation and then get it back to 2.2 after the operation and you’re good. But yes it’ll be simpler if it we had this button or if all softwares were in linear light like in Nuke:rolleyes:.