I think it really does depend on your actual monitor. Some monitors just wont be able to show the whole range of tones. For instance, I have 3 monitors. A Dell, which is quite dark, a Samsung SyncMaster, which is very bright and also has gamma correction, and a Cintiq which is in the middle.
Now I can adjust the SyncMaster by eye using the Gamma boxes (ie where the middle box disappears into the outter box) and the screen still shows a good range of tone both in highlights and shadow.
However doing that on either the Dell or the Cintiq means I totally loose the tonal range in the very dark and the very light. It is simply a limitation of the screen. So personally I never use Adobe Gamma.
I’ve forked out for a Spyder3Pro to do my screens but still their tones don’t exactly match. However before that I turned off Adobe Gamma completely and tweaked the tones/gamma via my graphics card (Nvida). I then used sites such as Thisand this and this to check I could see the tonal range. I doesn’t help with colour just tone.
If everyone is saying that your images are too dark then you probably do have your screen too light. This will mean once you darken the tone on your screen you’ll probably have to tweak your images to lighten them. Have a look at the links above to check you can see a good range.
Yep, just remember photoshop is first and foremost an app aimed at prints so you should absolutely be using a spectrometer on your monitor to calibrate it. Otherwise you are only adjusting your monitor for you and no other device. Spyder isnt quite as good as xrite Ive found and to be honest, unless you have a high gamut monitor with hardware calibration its never goin for be perfect. Firstly check the working colour setting in photoshop AND the profile embedded in the actual image file itself. If in doubt you can assign a new profile to the image and then you know for sure. Also you should check image>mode and check the file is RGB colour and look at the bit depth. I have still found strange results at 32 but even on cc2017 the results are still way flatter than I saw in maya…