kjoro on reddit wanted to compare the Lumia 640 XL camera against that of the Nokia Lumia 920 and Nikon D610.
You can view the album on Imgur here: http://imgur.com/a/cKmYQ
I was surprised how nice the 640 XL pictures look. Front camera wise, the 640XL makes the 920’s front camera look terrible.
The Nikon is there just for reference.
Whilst the 640XL produced better photos, the 920 apparently still focused faster. Plus it had a nice shutter button.