The first thing is to understand what kind of shot you want, one with the bird in the distance and the feeder in it and everything sort of sharp or one with the hummer close up, away from the feeder, and everything in the background sort of blurred. These shots require different settings. When I've shot hummers I go for the close up of the hummer, using both the camera's tools and my processing software tools, and I use a wide open aperture with the lens set at maximum distance. I try to avoid the feeder if at all possible. My lens is an 80-400 Nikkor. I have included two shots below, shot at either 5.6 or 7.1 and 400mm. I set the shooting mode to manual and use the setting that allows me to take multiple shots in succession with the focal point on the eye or head as near to the eye as possible. As soon as I see the bird I start to shoot, but prior to that I have focused, using back button auto focus, on the edge of the feeder so that I don't have to worry about that. Also put tape or cotton in the feeder holes you don't want the bird to use and put your feeder where the sun hits it to benefit your shot, mine work best in the afternoon when the sun is straight on but filtered by the trees in my yard. In post I remove any parts of the feeder using Photoshop. In Lightroom I upsize the photo using the Transform tool, this does not crop off pixels. Keep trying, it takes patience and many not so good photos to learn all the techniques.