Yesterday I shot a friend. The pictures looked OK on the camera screen. The hair with the help of hair light is distinguished from the black background. However, after I uploaded the pictures into my computer, I found that the pictures looked underexposed. The hair usually is just blended into the black background. I had to turn up the exposure or brightness, also the fill, in order to get the result that at least separate the hair from the background.
What should I do to avoid this kind of situation? Both the brightness of camera and of the monitor (which is an HDTV) are at the default neutral setting. Of course this is no guarantee. But I'm at a loss which one to trust. Would it be that the pictures directly from the camera are OK but my monitor brightness is just too low? Or the other way round? How can I tell?