# EF-M 18-55 IS STM vs EF-S 18-55 IS test



## noncho (Aug 12, 2013)

EF-M 18-55 IS STM vs EF-S 18-55 IS test

I have read some reviews where the EF-M kit is smaller, better(image and build quality) than EF-S.

Here is my test case:

Canon 60D + EF-S 18-55 IS I
Canon EOS-M + EF-M 18-55 IS STM
Same sensors.
100 ISO, F8, 1/160-1/250 speed.
RAW + Lens correction.
100% crop, left EOS-M, right EF-S.


18mm, center(click for full size):





http://g4.img-dpreview.com/6AA2059CAB4E488F8AA719C130293629.jpg


18mm, border:




http://g3.img-dpreview.com/BA86C8EE53C44F0E9331276D42274744.jpg


55mm, center:




http://g2.img-dpreview.com/B11C37E284D5469C8B849B80D7A41016.jpg


55mm, border:




http://g3.img-dpreview.com/44887082F5B54184A1B5E2F66E1F39BE.jpg



Conclusion:

EOS-M has better image quality(sharpness, aberrations).
In my opinion EF-M 18-55 IS STM is somewhere between 18-135 IS STM и 15-85 IS USM and this is impressive.
I have a test pics on 35mm/F8 and at 18, 35, 55 @5.6 and results are not very different - EF-M is better on every tested focus distance and aperture.

After the tests I have sold the EF-S 18-55, I'll use the M when I need a kit lens. 

P.S. Could be interesting to test EF-M vs new EF-S 18-55 IS STM, but I don't have it.


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## Bruce 101 (Aug 12, 2013)

> In my opinion EF-M 18-55 IS STM is somewhere between 18-135 IS STM и 15-85 IS USM and this is impressive.



There's really very little room between the image quality of the 15-85 and the 18-135 STM according to the tests. Although the 15-85 does show a good bit more purple fringing. Still the 15-85 is a tad sharper at 50mm.

See here:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=678&Camera=736&Sample=0&FLI=4&API=2&LensComp=675&CameraComp=736&SampleComp=0&FLIComp=5&APIComp=0


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## neuroanatomist (Aug 12, 2013)

noncho said:


> Here is my test case:
> 
> Canon 60D + EF-S 18-55 IS I
> Canon EOS-M + EF-M 18-55 IS STM
> Same sensors.



Why do people assume that just because both are 18 MP sensors, they are 'the same'? The sensors are (slightly) different, and the firmware and Digic image processor are also different between the two bodies. In fact, when the same lens is compared on the 60D vs. the EOS M, the images from the EOS M are visibly sharper. 

Because of that, your 'test case' isn't a valid comparison of the two lenses, although it is a valid comparison of the two specific systems, 60D + EF-S 18-55 vs. M + EF-M 18-55, and as you state, the latter delivers sharper images. Incidentally, the EOS M + EF-M 18-55 is also sharper than the 60D + EF-S 18-55 IS STM, especially at the long end. 

The proper test for just the lenses would be to test both on the EOS M, using the EF Mount Adapter to test the EF-S 18-55 lens.


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## noncho (Aug 12, 2013)

neuroanatomist,

I don't think that it's a big difference between sensors, especially in RAW. I agree testing with EF mount adapter is probably the best, I would do it when I have one. 

I just can say that the final result is impressive


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## neuroanatomist (Aug 12, 2013)

noncho said:


> I don't think that it's a big difference between sensors, especially in RAW.



I guess we just have a different opinion of the magnitude of that difference. The comparison I linked is based on RAW images, converted to JPG with the same settings in DPP (obviously, you can't really view a true RAW image anyway).


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## bholliman (Aug 13, 2013)

neuroanatomist said:


> Why do people assume that just because both are 18 MP sensors, they are 'the same'? The sensors are (slightly) different, and the firmware and Digic image processor are also different between the two bodies. In fact, when the same lens is compared on the 60D vs. the EOS M, the images from the EOS M are visibly sharper.



I've been guilty of making this assumption as well. Thanks for pointing this out!


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