Patent: Canon EF 24-300mm f/3.5-5.6

[Canon Rumors Guy]

<p>Another <a href="http://egami.blog.so-net.ne.jp/2016-01-04" target="_blank">patent for a full frame superzoom</a> has appeared from Canon. We’ve written about the development of such a lens a <a href="http://www.canonrumors.com/new-superzoom-development-cr1/">few times since May of 2015</a>, most recently this <a href="http://www.canonrumors.com/superzoom-development-mentioned-again-cr2/">past November</a>, and we continue to see more patents for such a lens.</p>
<p>Patent Publication No. 2015-215438 (Machine Translated)</p>
<ul>
<li>Published 2015.12.3</li>
<li>Filing date 2014.5.9</li>
<li>Focal length 24.70 101.33 292.01</li>
<li>Fno 3.50 4.59 5.87</li>
<li>ω (degrees) 41.22 12.05 4.24</li>
<li>Image height 21.64 21.64 21.64</li>
<li>Overall length of the lens 202.71 232.50 288.71</li>
<li>BF 38.78 43.69 75.66</li>
</ul>
<p>I think it’s safe to say we’ll be getting a new full frame superzoom in some form in the near future.</p>
<span id="pty_trigger"></span>

 

[jebrady03]

Non-L, STM motor. That to pair with a FF, DPAF sensor, would make some sense, to me.

 

[bkxmnr]

Someone will need to school me on how apertures work. If I'm doing the math right, an f number of 5.6 at 300mm requires a 53 millimeter aperture. That should, in theory, result in an f number less than 0.5 at 24mm. And yet it's only f3.5. What am I missing?

 

[RGF]

This could be a very interesting lens. Wider than the current 28-300. Since Canon has increased IQ on a number of lens. Hope this lens is another one.

 

[neuroanatomist]

Someone will need to school me on how apertures work. If I'm doing the math right, an f number of 5.6 at 300mm requires a 53 millimeter aperture. That should, in theory, result in an f number less than 0.5 at 24mm. And yet it's only f3.5. What am I missing?

Your math applies only to telephoto lens designs, where the entrance pupil sits at or just behind the front element.

 

[unfocused]

Yes, if this materializes, it will be interesting to see the quality, price, weight and the IS modes.

 

[Talley]

I've been waiting for a 24mm-300x superzoom from canon. This would definately be on my list for vacationing.

Would be one hell of a safari lens.

 

[applecider]

Trying to post some comments about comparison to 28-300, hoping the newer lens can be lighter, with more sharpness at 300 to the point where maybe an extender could be used. My posts are disappearing, so to be brief the ultimate travel lens needs to be portable will probably be expensive if it truly serves as a reasonable one lens solution.

I've only seen one 28-300 in the wild, not sure it was a wide seller.

 

[Mt Spokane Photography]

While such a lens would be improved over the existing one, assuming Canon goes ahead with it, a Superzoom is always going to be a compromise. They can be made lighter using the rear focus designs and materials that Canon now favors, and have better IS. The push-pull will be abandoned for a twist zoom like the 100-400L MK II, but don't expect IQ miracles, it isn't going to happen. Do expect a $2700 or more price tag, that's where the existing 28-300 started.

 

[Mancubus]

Would be definitely nice to see some Non-L alternative (under $900) to the expensive 28-300mm.

These "superzoom" lenses are not on par with shorter zooms or primes, so the more serious photographers (most of the ones that would spend over $2000 on a lens) will never go for it, and this is probably why most people here have almost never seen one.

I also think that 28mm is not wide enough, so if the new one comes at 24mm it will be a big plus. I believe many people will buy this lens for those days you don't want to carry anything else nor change lenses, but it has to be affordable.

 

[Wizardly]

Once again Egami doesn't post the entire patent.

Working example 1:
Image Height: 21.64 mm (135-format)
Focal Length: 28.9 / 90 / 204 mm
Fno: 3.36 / 4.59 / 5.88
BF: 38.66 / 45.8 / 58.33 mm
Length: 178.45 / 211.44 / 228.35 mm

WE 2:
Image height: 21.64 mm (135-format)
Focal length: 24.70 / 101.33 / 292.01 mm
Fno: 3.50 / 4.59 / 5.87
BF: 38.78 / 43.69 / 75.66 mm
Length: 202.71 / 232.50 / 288.71 mm

Example 2 has a wider front (beam diameter of 65.47 mm vs 59.97 mm). Example 1 seems to have slightly better distortion control.

 

[Mt Spokane Photography]

Would be definitely nice to see some Non-L alternative (under $900) to the expensive 28-300mm.

These "superzoom" lenses are not on par with shorter zooms or primes, so the more serious photographers (most of the ones that would spend over $2000 on a lens) will never go for it, and this is probably why most people here have almost never seen one.

I also think that 28mm is not wide enough, so if the new one comes at 24mm it will be a big plus. I believe many people will buy this lens for those days you don't want to carry anything else nor change lenses, but it has to be affordable.

A surprising number of posters here have owned the 28-300 or the 35-350. On FF, 28mm is reasonably wide, but the lens is cumbersome and heavy, so its definitely for a buyer who has the need for a one lens does it all. The original intended buyers for the lens were PJ's who had to cover both wide and telephoto, and switching lenses was impractical. Those buyers have gone away, replaced by smart phone photos, or still grabs from video. This leaves me wondering if they would actually produce one. Canon does not just make products with the hope that there are buyers, so they will not produce it without a fairly certain market.

This is a photo of my 35-350L. The hood on it is a thing of beauty!

My 28-300mmL IS was very nice, But I liked the original better.

 

[9VIII]

Someone will need to school me on how apertures work. If I'm doing the math right, an f number of 5.6 at 300mm requires a 53 millimeter aperture. That should, in theory, result in an f number less than 0.5 at 24mm. And yet it's only f3.5. What am I missing?

What you see below is an f2.8 lens.
Maybe being able to look behind itself explains most of the oddity here, but it still makes a point about how lenses change at extreme focal lengths. Anything shorter than 40mm is going to have to have significant changes to the formula, usually adding a lot of elements.

http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/fisheyes/6mmf28.htm

 

[[email protected]]

Interesting would Canon do 2 versions one without L glass (like the Nikon equivalent which yields some good results) and one withall the bells and whistles and quality on par with the Canon 100-400 MK 2

 

[j-p]

Someone will need to school me on how apertures work. If I'm doing the math right, an f number of 5.6 at 300mm requires a 53 millimeter aperture. That should, in theory, result in an f number less than 0.5 at 24mm. And yet it's only f3.5. What am I missing?

focal length/ f-stop = aperture ; 300/5.6 = 53mm ; 24/3.5 = 6.85mm. I don't understand your theory.

 

[vscd]

Make it fixed f2.8 and I'm in

 

[neuroanatomist]

Make it fixed f2.8 and I'm in

They'll have to include a Sherpa...

 

[neuroanatomist]

Someone will need to school me on how apertures work. If I'm doing the math right, an f number of 5.6 at 300mm requires a 53 millimeter aperture. That should, in theory, result in an f number less than 0.5 at 24mm. And yet it's only f3.5. What am I missing?

focal length/ f-stop = aperture ; 300/5.6 = 53mm ; 24/3.5 = 6.85mm. I don't understand your theory.

You need to rearrange your formula – f/stop is not a measurement, it's a calculated value based on focal length and entrance pupil diameter. His point (though incorrect) is that a lens with an entrance pupil diameter of 53mm could be f/0.45 (24mm / 53mm). Of course, it's not for a variety of reasons.

On this forum, we frequently discuss the relationship between entrance pupil and front element diameter (e.g. the 600/4 has a 150mm front element, a hypothetical 600/5.6 would need a 107mm front element and that's why we won't see a cheap consumer 600/5.6 from Canon). Many people start erroneously applying that sort of logic to all lenses, when in fact it applies only to true telephoto designs (because of the position of the entrance pupil, which is the optical projection of the iris diaphragm). For those interested, Roger Cicala wrote a nice set of articles on lens designs a while back.

 

[rfdesigner]

Someone will need to school me on how apertures work. If I'm doing the math right, an f number of 5.6 at 300mm requires a 53 millimeter aperture. That should, in theory, result in an f number less than 0.5 at 24mm. And yet it's only f3.5. What am I missing?

Take a look at a wide angle lens and you'll see the entrance pupil is smaller than the exit pupil, (my 28f1.8 certainly is) so a zoom at the wide end is dominated by the rearmost elements. To get f0.5 from the rearmost element, you'd need a 88mm diameter light cone at the exit of the lens (44mm lens-sensor distance). To avoid excessive vignetting you'd need it bigger than this, so let's say 100mm diameter. How big is your camera mount?

 

[tr573]

Would be definitely nice to see some Non-L alternative (under $900) to the expensive 28-300mm.

These "superzoom" lenses are not on par with shorter zooms or primes, so the more serious photographers (most of the ones that would spend over $2000 on a lens) will never go for it, and this is probably why most people here have almost never seen one.

I also think that 28mm is not wide enough, so if the new one comes at 24mm it will be a big plus. I believe many people will buy this lens for those days you don't want to carry anything else nor change lenses, but it has to be affordable.

Tamron makes one - it's not a miracle of IQ and has to be shot stopped down, but that is what you get if you want it compact and not so expensive. It's a good snapshot lens for stuff like "I have small kids and we are going to a theme park" , where size is a major concern.

Up for debate is whether you're better served by a 1" sensor superzoom for this purpose, but if you like a big OVF & fast autofocus with tracking (the Tamron is still faster than any compact camera I've ever used) , then a lens like this on a FF DSLR is your compromise.