Patent: Canon EF 100-400 f/4.5-5.6 IS STM

[Canon Rumors]

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A new patent for an EF 100-400 f/4.5-5.6 STM has appeared. Also in the patent is the EF-S 55-250 f/4-5.6 IS STM, so this patent is probably just covering an additional optical formula that will not become a product. I’d think any 100-400 replacement will be an L lens with an Ultrasonic Motor instead of an STM.</p>
<ul style="color: #444444;">
<li>Patent Publication No. 2014-102462
<ul>
<li>Publication date 2014.6.5</li>
<li>Filing date 2012.11.22</li>
</ul>
</li>
<li>Example 1
<ul>
<li>Zoom ratio 4.24</li>
<li>Focal length f = 56.90-133.00-241.28mm</li>
<li>Fno. 4.12-5.04-5.83</li>
<li>Half angle ω = 13.50-5.86-3.24 °</li>
<li>Image height 13.66mm</li>
<li>154.33-176.38-191.20mm overall length of the lens</li>
<li>BF 41.21mm</li>
</ul>
</li>
<li>Example 5
<ul>
<li>Zoom ratio 3.73</li>
<li>Focal length f = 104.59-199.99-389.99mm</li>
<li>Fno. 4.58-5.03-5.87</li>
<li>Half angle ω = 11.69-6.17-3.18 °</li>
<li>Image height 21.64mm</li>
<li>245.09-285.06-308.91mm overall length of the lens</li>
<li>BF 68.73mm</li>
</ul>
</li>
</ul>
<p>Source: [<a href="http://egami.blog.so-net.ne.jp/2014-06-19" target="_blank">EG</a>]</p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>

 

[Khufu]

Is the STM design, whilst having obvious benefits over other non-STM lenses, still somewhat inferior to L-standard USM engineering? Is 'STM' not branding we're ever to expect to see on an L Lens? Just curious, I'm not too educated on this front... though I'm sure my 400/5.6L's 2-decade old USM design is as smooth and silent as my two EF-M STM lenses!

 

[JonAustin]

Is the STM design, whilst having obvious benefits over other non-STM lenses, still somewhat inferior to L-standard USM engineering?

Not sure how superior USM is over STM from a practical standpoint, but note that this patent is not for an L lens. So I would presume that other factors -- such as optics and build quality -- would be stronger differentiators between a lens based on this patent (if one ever surfaces) and the rumored 100-400 f/4.5-5.6L IS USM II (if one ever surfaces!).

 

[dufflover]

Would the USM/STM thing affect the optical formula much? I'm a bit busy to go comparing the patents/existing designs to see if they're similar, but what I'm thinking it would be nice to see what kind of optical formula is involved and whether it would nonetheless still be a decent improvement on the current 100-400L given it's age and how a lot of the new lenses are so much better (L or otherwise)

 

[Antono Refa]

Is the STM design, whilst having obvious benefits over other non-STM lenses, still somewhat inferior to L-standard USM engineering?

STM & USM target different audiences with different requirements.

 

[SwissBear]

so far, we have seen superfast USM and slower STM lenses.
But technically, STM tech could be as fast as USM, still with the possibility to slow down when needed.

I guess wildlife videographers would really love an STM tele lens...

 

[unfocused]

I wouldn't completely dismiss this.

The relatively low-cost and popularity of the 6D is putting a lot of full frame bodies into the hands of consumers stepping up from crop sensors. These customers are losing reach from their old 70-300mm lenses. The 70-300 IS is a weak performer long-overdue for replacement.

A consumer-priced 100-400 with compromises like STM and, presumably, less robust build, (similar to the EF-S 55-350 STM) could be a big seller for 6D step-up customers, especially for those interested in video.

 

[dgatwood]

I love my 70–300L, but I'm finding myself frequently annoyed at the lack of reach after moving from crop to a 6D. I've considered moving to a 100–400L, but my 70–300L is already on the verge of being so long and heavy that I can't deal with it in the field. The 100–400L is two inches longer and a third again heavier. That's just beyond what I could ever consider carrying around with me.

I'm impressed that this proposed lens is only about .4" longer than the 70–300L. If that dimension turns out to be accurate, I might be able to deal with this lens. With that said, I'd much rather see a DO version of the 100–400L, so that I could get something approaching L quality images without having to deal with a lens that's so darn unmanageable.