The Old Fish Market, Venice

Roy has suggested a crop that would make the buildings a better focus.

Yes, he has, and he's wrong. The existing composition fits the square format perfectly, and should include the Renaissance loggia and pantiled roof (with its original water spout) of the historic fish market building, an important part of the picture, and not (as he proposes) truncate the columns half way.

Roy is not "wrong" but simply has a better sense of composition.

My own suggestion would be to make a slight crop to the roof, since we can barely see the pantiles, and include more water below.

In his opinion, not mine.