M5: why 15-45 instead of 18-55 as kit?

The 18-55mm (28.8-88.0mm equiv) was introduced to be a smaller alternative to the EF-S 18-55mm selling with the DSLR's. The EF-M 18-55mm is obviously for mirrorless and it is cheaper for Canon to spend time designing a new lens than selling adapters with the EOS M cameras.

The 15-45mm (24.0-72.0mm equiv) was introduced soon after the 18-55mm, 11-22mm, 22mm, and 55-200mm were around and was used for a replacement kit lens. Here's why:

1. A smaller lens build is cheaper. Having less size means less glass, less metal, and less plastic helping Canon boost up profits.

2. Canon saw more potential in offering a 24-70mm style lens rather than 28-90mm (old EF lens) style.

3. Lighter lens would mean better handling for beginners.

4. Mirrorless is all about the compact size and Canon are probably trying to make people come to mirrorless by giving lenses like these so they can head upmarket with DSLR's. Currently the EOS Rebel, EOS M, and PowerShot G series are all on par with each other and I think Canon are trying to move the EOS Rebel up. This is evident with the SL2/200D, being marketed lower than the T6/1300D but with more advanced features and higher price. I think the EOS T7/T8/1400D will slot above the SL2 when it comes out. Essentially, the bigger the body the 'higher up' it is.

But how do they get stunning quality in a lens that small??? (It puts all EF-S 18-55mm's to SHAME)

1. A shorter flange focal distance removes the limitation of having to place elements further from the camera. This means a potentially closer lens allowing for small design.

2. Canon have made good use of this. The element closest to the sensor is really close. This means a potentially simpler construction particularly for wide-angle focal lengths.

3. Retraction mechanism. Great quality will involve a medium-to-big zoom lens, but retraction allows close position of elements to shrink the lens size.

4. 3 Aspherical lens elements. Having aspherical lenses corrects abberations at the cost of more time and money. However Canon have realised that they need to innovate in mirrorless and create more compact products.