But as https://www.tandfonline.com/doi/pdf/10.1080/1464518031000160... points out, the analysis technique that makes it possible to deduce the structure from the image was first developed 2 years earlier in a paper by Crick, Cochran and Vand. Note the lead author. In 1953, Francis Crick was one of a handful of people on the planet who would have made the connection. In fact he was able to make it from James Watson's description of the photograph! Rosalind Franklin can be pardoned for having failed to make the connection.
The fact that Crick was the world expert on the one obscure thing about crystallography that mattered here doesn't mean that Franklin wasn't the real expert. Every expert has gaps in their knowledge.
The necessary analysis technique was first developed 2 years earlier, in a paper that Crick was the lead author on. Chance favors the prepared mind. And Crick was extremely well-prepared for this task.
This particular issue is quite complicated. See: https://en.wikipedia.org/wiki/Photo_51
https://www.encyclopedia.com/science-and-technology/biology-...
Franklin had put the photograph aside to concentrate on the A form. She was preparing to transfer to Birkbeck College, also in London, and had been instructed to leave her DNA work behind.
I don't think that's the lore. The lore is that Franklin sat on the data for months before analyzing it (she wanted to collect more data). Then W+C visited her lab and saw the data, but did not instantly understand it. Instead, the lore is that they figured out the structure of the DNA through a combination of going on daily walks, playing with models, and taking LSD.
It is Linus Pauling who would have been able to instantly figure out the structure of DNA by glancing at photograph 51. His initial theory had been that the phosphates were on the inside of the structure, which in hindsight would never work because the negative charges would repel each other.
Source: I had a good AP Bio teacher