My image look changes when i modify the render resolution If i render my scene in 1280x720 it looks ok but whe i increase the resolution to 2560x1440 the ground looks darker . I only changed the resolution,nothing more:

The first image was a test and the second a final render . I want the final render to look like the first image.What i should do ?
(THE UNFINISHED RENDER HAS 2560X1440 AND THE OTHER ONE 1280X720)


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This may be caused by the resizing process, when the software used to display the rendering tries to fit the image onto the size of your monitor.