In GUI photo editors that have a control for "gamma", I find this helps a lot with fixing vibrancy/fade issues, without greatly distorting anything else.
But several programs lack an explicit "gamma" control, and I find that hue/brightness/saturation aren't quite the same, while levels require a lot of working around to balance the different channels (master + 6 channels, not very successful!).
What does gamma actually do, and, what is the nearest equivalent for "gamma" on programs lacking an explicit "gamma" control (or how can I easiest get the same effect) in such programs?
Update at the moment I'm using an older version of Adobe Photoshop Elements (v10) and at times the MS Office 2010 Picture Editor. I might use other tools in future such as Photoshop or Gimp but right now I'm not a heavy graphics user; my editing is mostly related to making features clearer or more true to life in photos. I'm not looking for exaggeration of colouring for effect, as seen in some uses or on TV, but sometimes enhanced clarity is useful to let features be easily seen when photos are used to confirm what they show.