Originally posted by blackest To be honest I thought it was fine but someone questioned if it was level and it's hard to say the exif says it isn't. Although Issac Newton was from my home town I don't think i'm up to arguing with gravity, life is too short.
If the EXIF says there was rotational or pitch tilt, the camera was not level when the photo was taken. The correction to apply is to hold the camera straight!
You can use the viewfinder edges as a guide along with the etched lines on the focus screen match up to known vertical or horizontal features in the frame. In Live View, there is are two level indicators that can be quite helpful, particularly when using a tripod. There is also an option of having a level indicator in the optical viewfinder. I hesitate to suggest that option because it replaces meter information.
Your camera also has an auto-horizon correction feature, but what you see in the viewfinder may be different from the actual photo. This is equivalent to correction in post-processing and I suggest leaving it turned off.
BTW: As noted above, obsessing over perfectly level composition may be counterproductive. Compose to your own best judgement.
Steve
P.S. The water surface may be level, but waterlines are deceptive and seldom parallel to the horizon.