Which 35mm 1.4 has the "flattest" focus field at close distance?

I have had a Nikon AF-S 35/1.4 for a couple of months.  My impression is that it has a fairly flat field and excellent detail rendition in the close up range.  Better than most Nikon/Zeiss wide angles.  It is definitely worth investigating for your project.  The Sigma is cheaper and everybody says it's super-duper; The big unanswered question with the Sigma is build quality and long-term durability, however, that potential issue may not matter for your narrowly focused needs.

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