Finally found the answer to a problem that has vexed me for some time now with my Canon camera bodies. Manual mode is my favorite choice for shooting bird photography, but the problem of quickly setting exposure compensation (EC) has always forced me to use Shutter Priority (Tv) mode instead. The reason for that is when you are in manual mode the front wheel adjusts the shutter speed and the back wheel adjusts the aperture. In Tv mode the front wheel adjusts the shutter, the back wheel adjusts EC and the camera selects the best aperture for that shutter speed, which is fine except you have no control over the aperture. In my case most of the time with my long lens the camera is going to select F8 or F9, both of which are going to be acceptable. However with a very fast lens where I might have more choices it would be nice to control both shutter speed and aperture in manual mode.
Now of course you can go to the menu to adjust the EC and if your camera has it, the Q button on the back will bring up all your settings, one of which is the EC that you can set with your touch screen or change with the back wheel on older bodies. I have never found this to be an acceptable solution for bird photography, especially in the case when the bird is flying past mountains where part of the time the sky is the background and part of the time trees are the background. When the bird is flying in and out of bright backgrounds you have to be able to quickly adjust your EC without losing focus on the bird.
Thanks to Janine Krayer of Pangolin Wildlife Photography pointing this out in her Canon Camera Hacks video, I have been able to program my 90D to overcome this problem. In the Custom Functions Other #3 menu you will find the button assignments menu, one of which of course is the set button. The set button comes set to off in the default camera settings which does you no good at all. Setting the button to adjust EC creates the ability to quickly adjust the EC using the front wheel. Flash exposure compensation (FEC) is also one of the options for this button which would also come in very handy when using your Speed Light. I went ahead and set it to regular EC, but would probably change it to FEC during a flash photo shoot.
The * button is also performs a function just asking to be reprogrammed. Normally the * button locks in an exposure value, which if bumped accidentally when using it’s next door neighbor for back button focus, will completely jack up your next exposure. Janine suggests setting it to off, but on the 90D it can also be set to manage EC, which is what I set it to. Now I have two buttons for EC, but in the case of flash photography I would have one for EC and one for FEC if I choose to program the camera that way.
Of course this is only the exact solution for Canon cameras, but I imagine other vendors have the same issue and have also devised a way around the problem as well. Check your manuals for instructions on how to do this!