Yes, I agree that focus breathing is acceptable in a lens, for that price, however I also agree with XVNM that this is dissapointing regardless.
Again, I disagree. While the motor may be good for video because of its sound, or lack thereof, it's a $199 lens! Even lenses that cost thousands of dollars exhibit focus breathing.
The Kia Rio starts at $13,600.
The Ferrrari 458 Speciale probably costs 20x that.
You might be disappointed that the Kia can't take a corner at 60 mph or go 0-60 in a couple of seconds, but you should be just as disappointed that Santa Claus and the Easter Bunny don't really come and bring toys and candy to little boys and girls. None of these expectations are realistic.And the issue of focus breathing is relevant particularly so for video users
I didn't say that it wasn't. I said/meant/implied that being surprised/disappointed by it in a sub $200 lens was ridiculous.
Back when I shot film, Canon made a piece of crap plastic 28-70 3.5-5.6 lens (the so-called "plastic fantastic" that was literally a throw in/throw out lens) and a 28-70 2.8 L lens. If you got a good copy of the latter (which I did) you could make some really nice images. If you had the former and compared them, even at f/5.6 it was Ford Pinto vs Mercedes SL class convertible (I guess I'm in a car mood today). Maybe even a bicycle vs the Mercedes. You shouldn't expect to be able to extract gold from a pile of manure and be disappointed when you can't. That's like, well, being disappointed after staying up all night and seeing that Santa did not shimmy down your chimney.
And, btw, focus breathing can be observed in the 24-70 2.8 II at all focal lengths, as well as in the 70-200 2.8 II.
Just because a relatively cheap lens has an STM does not mean it's not going to be a relatively cheap lens designed primarily for still cameras, STM or not.
Canon's Description:QuoteA unique and indispensable addition to Canon's series of EF lenses, the new EF 40mm f/2.8 STM offers an ultra-slim and lightweight design. Incredibly compact in size, the EF 40mm f/2.8 STM delivers high image quality from the center to the periphery thanks to its advanced lens configuration including an aspherical element, a bright 2.8 aperture, and optimized coatings that minimize ghosting and flare while providing exceptional color balance. The EF 40mm f/2.8 STM's unobtrusive design helps the photographer avoid overwhelming their subjects with a large lens and to remain discreet in sensitive shooting situations with no compromise in performance. Its diminutive design is complemented by features such as a newly developed stepping motor for smooth and quiet continuous AF while capturing video with the Canon EOS Rebel T4i DSLR, a circular aperture (7 blades) for beautiful soft-focus backgrounds, and a short minimum focusing distance of only 0.98 ft./0.30 m.
It delivers the "smooth and quiet continuous AF while capturing video...". I don't see it promising more than that. In fact, it seems to me that it delivers well on its promises.
I disagree, my particular copy of the 40mm pancake performs more like a skateboard.
Anyways, you're right about having ridiculous expectations for such a cheap lens, despite the incredible value it actually is. Many people in these forums tend to have ridiculous expectations