Adams, well known for his spectacular landscapes, has left several books (e.g., Examples: The Making of 40 Photographs, and, The Print.) and considerable documentation as to the hundreds of hours and many steps he took in the darkroom on each of his final prints.  Consider one of Adams' master pieces Winter Sunrise, Sierra Nevada, California (1944).  In The Print, p. 126, he describes the many ways he manipulated the negative to create his final print.  More telling, to me at least, was what he said about the same picture in another of his books called: The Making of 40 Photographs: 

            The fact that Adams manipulated his images from negative to print is obvious from reading his books, but not from viewing his pictures.  He was truly a master inside and outside of the darkroom. 

            Though Adam's darkroom tools were more primitive than those available in modern photo-editing software, they were nevertheless quite powerful in his hands.  He left nothing to chance.  He decided, first, where he wanted us to look.  Then, he dodged, burned and manipulated elements in the picture to create the final image.  In The Making of 40 Photographs, Adams even provides us with  the details of all the steps he took to make prints.             

            Immediately upon reading the quote above, I realized what my problem was.   I was mislabeling myself.  I was thinking like a photo journalist, not like a fine-art photographer.  For my purposes as a fine-art photographer I realized that beauty had to be more important than truth.  Journalistic photography is a type of photography in which the photographer is primarily concerned with portraying events exactly as they happened.  Hopefully, little if any photo editing is done.  Perhaps, because a photograph was taken while the photographer was running, the horizon line is sloping and needs to be straightened.  A journalistic photographer would do this to make the resulting photograph more readable.  Ultimately, truth is much more important than beauty in journalistic photography.  (For more on the differences between photo journalism and fine-art photography see A Nomenclature for Photography.)

   Fine-Art Photography, instead is an attempt by the photographer to create photographs that people want to look at.  The fine-art photographer may do significant photo editing on a given picture to bring out the beauty that is already there, much as you moved the rug to make your home look its best, or put another coat of wax on your car.  Though both truth and beauty are important to a fine-art photographer, in the end, the primary goal is beauty, not truth.  Once I had made the distinction, I had no problem taking out the water bottle, and I have never regretted it.  I've even toyed with the idea of making the blue tarp gray.  Hmmmmm.... maybe someday I will.

            Each of us as photographers have to decide what goal we are attempting to meet when we snap the shutter and when we process the resulting picture.  This does not mean we can only be one kind of photographer.  However, journalistic photography, because it is based on the trust of the viewer, is more fragile.  The more a given photographer bends the boundaries of trust, regardless of whether it is in the name of beauty, the less credibility that photographer might have for a viewer looking for truth, and the less credibility people have in photo journalism, in general.

            As a fine-art photographer, all I ask is that you permit me to create the wonderful illusion of beauty, just as you would a painter or a sculptor.

             By the way, I think the real reason why people ask the question, "is it real, or has it been photo-shopped?" is because something about the photograph they are viewing doesn't look right.  The question points to incompetency in the use of photo-editing tools.  No one looks at an Ansel Adams picture and suspects it has been manipulated - even though it has.  Thus, the best way for the photographer to hear that question less is to do her or his craft well.