I assumed the same, so I re-rendered at 400%. The file size is 79mb as a radiance file. Is it normal to do this? Is there anything else I should consider?
btw - the larger resolution of course was sharper, but thats a gigantic file.
I have a few professional HDRIs lying around on my HDD - 10K x 5K at almost 250 MB. So, no, that’s not uncommon…
What you could do is use a low res version of that HDRI for lighting and a high res LDRI (which will use much less memory) visible to reflections and camera.