Canon Patents

Patent: Canon EF-M 15-45mm f/3.5-5.6 IS STM II

Canon continues to submit patent applications for an improved EF-M 15-45mm f/3.5-5.6 IS STM. The current version is inconsistent at best, some people get a great copy, but more often than not,  one gets a poor copy.

This new design seems to use 12 elements instead of the 10 in the current design. The patent also touches on improved AF performance from the EOS M kit lens.

Japan Patent Application 2018169618:

The zoom lens used for an imaging device is a wide field angle, and the whole lens system’s being small and a focus lens group can perform focusing at high speed by a small light weight, and, moreover, it is strongly requested on the occasion of focusing that there are few aberration variations etc. In order to make a focus lens group into a small light weight, it is necessary to lessen the composed lens number of sheets of a focus lens group. However, when the composed lens number of sheets of a focus lens group is lessened, the residual aberration of a focus lens group enlarges. For this reason, an aberration variation enlarges on the occasion of focusing, and it becomes difficult to obtain optical performance with a good rear spring supporter from a long distance to the object distance at large [ to a short distance ]

Jul 31, 2018
297
110
#2
about time they improve that lens. At the minimum, 15-45 Mk. II should be on par with the discontinued EF-M 18-55 (in overlapping FL range).


Edit: not "Mk II", because f/5.6 vs. f/6.3 on long end.
 
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#3
Maybe my second M50 to buy will be ordered with this lens if it enters the light of the real market! Good to see f/5.6 compared to f/6.3 - I hate these lower than 5.6 max. apertures!
The EF-M 32 has some addiction potential so I need a second M50 for other lenses!
 
#4
Hopefully the new lens improves the variation on each copy. My first two copies of the current 15-45 had tremendous decentering! It was like the left side of the frame was at a different depth of field in some photos, but it turned out that it was simply a shifted focal plane. I have a good copy now! But wow, I thought it was just a garbage lens at first. It's convenient for snapshots/video and when selling the camera, not much else.
 
Jul 31, 2018
297
110
#6
you are right! No Mk. II but rather .... "2nd coming of an EF-M 15-45 lens". :)

Anyways, important would be for this patent turning into a "real product" soon with very noticeable improvement in IQ and copy variation over the current 15-45 kit zoom. :)
 
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pj1974

EOS Rebel SL2
Oct 18, 2011
571
31
Adelaide, Australia
#7
Hopefully the new lens improves the variation on each copy. My first two copies of the current 15-45 had tremendous decentering! It was like the left side of the frame was at a different depth of field in some photos, but it turned out that it was simply a shifted focal plane. I have a good copy now! But wow, I thought it was just a garbage lens at first. It's convenient for snapshots/video and when selling the camera, not much else.
I bought a 2nd hand copy of the EF-M 15-45mm STM lens, and thankfully have a good copy. Very sharp in centre, and quite sharp at each of the edges too at all focal lengths. I really love the 15mm wide end, and 45mm tele end is 'ok' for some reach... but oh how I wish it had more reach, like my EF-S 15-85mm ... but hey, which is obviously a much larger lens.

From reading user and pro reviews online, it does appear copy to copy variation does exist for the 15-45mm lens. I have an EF-M 18-55 lens too, which is similarly sharp - with notably better build quality, but not as compact / convenient. In terms of IQ and range, the 18-150mm is the pick of the bunch, though significantly longer (again).

The 15-45mm is a great one lens option is wanting to keep things as small / light / portable as possible, with decent to good IQ, on e.g. my M5 (or my M10 as an option too). The f/6.3 vs f/5.6 doesn't really make that much difference. Particularly given that DPAF can focus at narrow apertures ok (though of course the lower the light, the brighter one wants a lens to be). That's why most often in low light I use my primes (e.g. Canon EF-M 22mm f/2 or Samyang 12mm f/2). That another patent for a 15-45mm is around is perhaps more experimental than production at this stage.

PJ
 

Bob Howland

EOS Rebel T7
Mar 25, 2012
383
9
#9
Wouldn't inconsistency in image quality indicate a manufacturing problem, not an optical design quality? How does a new design with a new optical formula correct a manufacturing problem?
 

Sibir Lupus

EOS M2 + EOS M10
Feb 4, 2015
80
25
35
#10
Hopefully, they are preparing this lens as the new kit lens for the M5 and M50 MkII's.
The M50 just came out this year, so I doubt a M50 Mark II is right around the corner. My guess is that this new EF-M 15-45mm lens will be the one included on the M5 Mark II and M6 Mark II, and/or the M200
 
Likes: pj1974
#11
Wouldn't inconsistency in image quality indicate a manufacturing problem, not an optical design quality? How does a new design with a new optical formula correct a manufacturing problem?
Maybe it is a problem to adust the current lens formula - optics and the corresponding mechanical parts - at low cost.
What about another design which is more tolerant to deviations from perfect alignment is cheaper compared to better adjustment of the old design?