In 1929 he renamed some of the original "Songs of the Sky" as "Equivalents", and these prints are still known by both names today. Dorothy Norman once recorded a conversation between Stieglitz and a man looking at one of his "Equivalents" prints:  Man (looking at a Stieglitz Equivalent): Is this a photograph of water? Stieglitz: What difference does it make of what it is a photograph? Man: But is it a photograph of water? Stieglitz: I tell you it does not matter. Man: Well, then, is it a picture of the sky? Stieglitz: It happens to be a picture of the sky. But I cannot understand why that is of any importance. Stieglitz certainly knew what he had achieved in these pictures. Writing about his "Equivalents" to Hart Crane, he declared: "I know exactly what I have photographed. I know I have done something that has never been done…I also know that there is more of the really abstract in some 'representation' than in most of the dead representations of the so-called abstract so fashionable now." The "Equivalents" are sometimes recognized as the first intentionally abstract photographs, although this claim may be difficult to uphold given Alvin Langdon Coburn's Vortographs that were created almost a decade earlier. Nonetheless, it is difficult to look at them today and understand the impact that they had at the time. When they first appeared photography had been generally recognized as a distinct art form for no more than fifteen years, and until Stieglitz introduced his cloud photos there was no tradition of photographing something that was not recognizable in both form and content. Art critic Hilton Kramer said that "Equivalents" "undoubtedly owe something to the American modernist painting (Dove's and O'Keeffe's especially) that Stieglitz felt particularly close to at the time. Yet they go distinctly beyond the pictorial conventions that governed avant-garde painting in this period by reaching for the kind of lyric abstraction that was not to enter American painting until the 1940s and 1950s. In the line that can be traced from the paintings of Albert Pinkham Ryder to, say, those of Clyfford Still, it is in Stieglitz's "Equivalents" – rather than in painting itself – that we find the strongest link." One of the reasons that the strongest of these photographs appear so abstract is that they are void of any reference points.