I do not know to which specific hdri maps you refer, but generally, as they are projected to an environment, you get to see a very small part of the image as a background (or, in other words, a very zoomed in region). I guess that is also a reason why really good hdr images are expensive, they are very high resolution images in order to appear unblurred. However, I am no expert on HDRI maps, maybe I am wrong. BTW you can also use hdrshop to make and edit hdr images

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