This is a Yellow Warbler like the one I posted last week. Yellow Warblers don’t sit still for long. They tend to be on the other side of small branches. The issue then is how to get a good focus on the bird. You notice that I am on the edge with the first shot and slightly off in the second. This is typical even with long lenses, a good camera and decent depth of field (e.g. F8). The camera is easily filled by the branches. You get the bird with what you think are good shots and discover you have better focus on the branches than the bird. Sharpening can help, shake reduction might help too. However the better answers are either not to shoot birds deep in the branches, or increase your F Stop significantly. The former works all the time, and the second in my experience can lead to more distractions than one would like in the background. Conclusion: small birds are hard to shoot and when you do get a good shot, celebrate.