[Brightcolours]

I can't recall the lat time I had a photo with a subject in the extreme corner.

 

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Most of the subjects in my photos usually closer to being on or within the orange circle.  The green circle is important for some images.  The blue circle is 99% useless...most of it is not even within the frame.  

 

PZ tests do not include data for the useful orange zone and give great importance to the blue zone.

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In landscape/cityscape shots with not a singular subject in the center, blurry extreme corners can be noticed at times. Not something too unusual, for 35mm. For some more than for others.