Keep in mind that the overall image probably would be this bright, if it is to be consistent with the previous close-up shots of Luke doing the handstand. It seems to be around noonish, as the area Luke and Yoda were/are located was/is pretty well lit (during the training sequence before Luke fell over) - which means you can't have a dark and gloomy X-wing shot if the previous shots were brighter (unless you darkened them to match).

Compositionally I can understand the brightness concern, being that you don't want Luke, Yoda or even R2 to get lost in the background (though that doesn't seem to be too much of an issue here, at least for me, as I can still clearly see all 3).

Here is a slightly modified version; I burned in some of the environmental elements around Yoda, Luke and R2 to help them stand out, to show a gradual "lightening" of the environmental vegetation as you go up (to show the effects of the sunlight being drowned out the deeper and lower you go).

... okay, it's not that much different... I think the main thing is making sure the X-wing stands out, as well as syncing the lighting between most of the shots as best as possible (you don't want to go from fairly well-lit to gloomy and then well-lit again).

The main idea is that you can replace the background with something with more appropriate detail (not just simply more detail, but something that looks more natural and blends in with the set Mark Hamill is on) and then adjust the lighting to the appropriate light or dark levels.

Another note: nothing big again, but either when Luke is trying to lift up the X-wing or any other shot, will there be any implication of the path the X-wing took to crash into the shore? As it stands, the X-wing would have travelled through some majorly thick trees to crash where it is (which would have killed Luke), short of him crashing straight down in a nose dive.