You haven't posted most of the hardware info anyone would need to help you with this
. . . . . . but if this is Windows bear in mind that windows GUI generally ignores any gamma profile saved in icc monitor files files (and loaded at startup but haphazardly thereafter/at reboot)
In consequence something that looks right in a colour-aware app like photoshop or latest google chrome will look different once saved and viewed /screenshotted in windows picture viewer /as a desktop image etc.
Older browsers ignore color profiles too but most current version have caught up. Few if any browsers display in other than sRGB though which affects images that used wider gamut profiles like Adobe RGB
You can go entirely mad on this but the best 'quick approach' is to re-set your monitor to defaults, gamma 2.2 if possible and to a 'factory preset like 'standard or sRGB' or far far better still, borrow a properly calibrated monitor for an hour.
Remove any 'super duper add in gamma tweak tools
Set all nvidea image and video settings to defaults including monitor's default (native) resolution and output range to full. Then choose the 'use system/app settings' option to take them out of the flow as far as possible for now.
Search Colour Management in Windows, click Profiles and "reset my settings to the system defaults" (unless you've already messed them up :-)
Then in colour management, advanced tab, complete the "Calibrate display" wizard to calibrate the GUI brightness / contrast / Gamma / colour (As you can guess if your monitor is not accurate in the first place this will probably only make things worse as you correct that error with more error)
Now you have the GUI calibrated use the latest version of chrome to view some nice downloadable wallpapers online. They should now look good in chrome.. Save them to desktop and view them again in Photos or save as a background. They should still look good albeit not quite the same
Now open them in Photoshop or similar colour aware programme. They should now look as good as before or even a bit better.
If they are not completely the same (and you have photoshop correctly set to sRGB etc) this is likely because they are now actually being displayed correctly - or if 'worse' you might now be tempted to fiddle a tiny bit with the nvidia settings but remember these might not get reloaded at a reboot / update.
Remember that nvidea has separate page for video settings but it is again often best to leave these to a decent video player app also.
I have to say that if your monitor is poorly calibrated and your reference is a poor set of photos vs test cards /gamma charts you will probably never see a decent image or get it truly right.
Gamma test cards are a very mixed bunch by the way - some don't always work even on a perfectly calibrated pro monitor when viewed other that at 100% pixel size or when downloaded from the web.
Hope that give you some ideas
Just in closing
99.9% of windows users don't worry about gamma because the pictures look ok at system defaults. If they are not 90% right at defaults there is a problem.
Adjusting gamma corrects for slight system or monitor errors. Ideally don't adjust the system if the monitor is the problem (may have no choice on a laptop where limited viewing angle is another issue)
The correct gamma for EVERYTHING on a PC these days is 2.2 /default. It will not need 1.4 or 2.6 to get a good image. If it looks better that way something is very wrong elsewhere in the image chain.
There is lot to get your head around if you don't understand the concept of the image flow through the system to your eyes /printer - It might be faster to buy a pro or semi pro photographer a few bottles and watch then put it right
Last edited by Jetstream67; 7th Aug 2018 at 23:20.