Upload & Sell: Off
I've done some stitching with it, its pretty good. (excellent for its price actually) Better/sharper than any of the Canon 50's I've tried, or the 45mm tse. But does not have the wow look of the 35L or 24L.
Only bad thing I can say about it, is it can be more tricky to manually nail the focus using live view, due to the tiny crappy focus ring. But it gets the job done.
This is 6 shots stitched with the 40mm.
Crop of above photo, showing more detail.