EF-M 15-45 extremely soft?

photo_mark wrote:

Those images are on the soft side.

Welcome to the Canon M forum!

The Canon EF-M 15-45mm IS STM lens has been discussed quite a bit in this group, and it's generally agreed there is quite a bit of 'copy' variation with this lens. While many copies are 'OK' --- many are also 'soft' in the corners, some of them very mucn softer on one side or the other (decentered) and a few people have posted samples of excellent copies that are sharper than most.

I've gone through 5 different copies of this lens. 2 of them were OK, 2 were noticeably softer along the right or left edge, and the one I finally kept is fairly sharp across most of the image, just slightly soft in the extreme corners at the wide end.

I also found that the resolution in the center of the lens is very good --- quite sharp, even at f3.5 at 15mm. The 'best' lenses optically that Canon makes for its M cameras are the 32mm f1.4 and 11-22mm f4-5.6 lenses, and the 28mm f3.5 macros is nearly as good.

Even the EF-M 18-150 IS STM and 55-200 IS STM lenses I've found are good lenses, slightly better than their older EF-S counterparts (EF-S 18-135mm IS STM and EF-S 55-250 IS STM) although the difference isn't very much.

I've now had no less than 6 of these - and not one of them has been extremely soft. In fact they've all been pretty decent, way better than one might expect for the cost, especially if one remembers kit lenses from the end of the film era...
Why 6? Well I bought 2 deliberately  (the first a Canon refurb item, the second from a friend and I had tested it first) because I needed one for me, one for my wife. The others came with bodies where it was often cheaper to buy the kit than body only, somewhat bizarrely.
Yes, the corners and edges do need to be stopped down a bit to be critically sharp, but what do you expect? They're not terrible wide open.  Not on the copies I've had, anyway. 
People mention the EF-M 18-55 as an alternative, and for some, it may well be. For me, it misses out on the critical 15mm setting - 24mm in full frame terms - which is my most-used focal length for personal use. And the 3 18-55s I've used have all been inferior optically - one was - is - OK, but not as sharp as the 15-45, the other two were badly decentered.  The 18-150 is a decent alternative if you don't need 15mm - again, one or two have reported some issues, but I've had no issues. I think the 15-45 is actually a touch sharper, at the wide setting anyway, but the 18-150 is so useful for travel.