Using DisplayCAL

I use DisplayCAL to profile/calibrate my monitors and had something happen last night that I've never seen before, and I'm hoping someone who's familiar with it can answer a question.

I started to do the interactive display adjustment before calibrating, and was surprised to find all three colors (RGB) and the brightness already meeting in the middle, along with the green "you're ready to go" indication. So of course I didn't make any adjustments, I just went ahead with the calibration.

My question is, "Did I need to calibrate?" Or does the fact that all the colors and brightness were lined up in the middle mean that my monitor hadn't changed since the last calibration? (3-4 weeks ago)

Thanks

Monitors will change over time, as the back light ages, screen coating ages etc, but it's a long slow process. Usually months for there to be any measurable change, longer for any perceptive change, some times years.

I was calibrating my monitors last night and one of the monitors was spot on for 6500K. The screen brightness was a little dim, so only had to adjust that. But, otherwise, you should recalibrate/update your calibration.