I have a video source that, to my surprise, has a lot more detail than I could at first see. Turning down gamma I could see details in a bright part, turning up gamma I could see details in a darker part. I did experiment with brightness for obvious reasons, as well as with saturation, but I seem to be stuck at 50% of the details. Is there really such a predicament in video reproduction that you have to sacrifice one for the other, is my monitor involved (pre-retina Macbook), or have I simply not found the sweetspot of all those image tweaks?
You want to adjust a mix of gamma, brightness and contrast, or if available, simply use curves. Gamma impacts the way in which the output intensity corresponds to input intensity, but if you don't also adjust other settings, you will still end up clipping key details outside of either the signal range of your signal or the display range of your display.
Using curves gives the most flexibility to adjust the amount of contrast in each portion of the range of signal intensity so that you can see everything clearly, however it is also possible you are simply near the effective limit of the range your display can produce depending on where the information you need contrast for is.
I suggest starting by trying to make sure your contrast or black point (on curves), is set such that you can tell the difference in shadow detail and then trying to adjust the brightness or white point (in curves) to get it so you can just tell difference in light detail and then try adjusting gamma to give you the needed spread.
Looks like you are ready to enter the world of Lift-Gamma-Gain! These are the three controls that most colorists use to tame light and the sensors that record it. AJ Henderson is putting you on the right path, with suggestions that there's more to image control than just gamma, levels, curves, etc., but really you will find a lot more resources by researching the subject of Lift, Gamma, Gain. (It's so fundamental that the bboard for professional colorists is liftgammagain.com)
Here's a graph that helps show how these three controls interact:
Once you are good with that, you might like to play with lift gamma and gain in log space, which are called shadow, midtone, and highlight:
There are many who will argue long and hard about which is best, most useful, most true, etc. I have found LGG is better for creatively manipulating the look of an image, whereas SMH is better for being more surgical. Explore and report back!