Patent: Canon EF-M 16-80mm f/2-6 for APS-C

[Canon Rumors Guy]

A patent for a new EF-M lens has appeared. We’ve been told that there will be 3-5 new lenses coming for the EF-M mount in 2016 and at least one will be a new kit lens. This patent is for an APS-C sized sensor and the optical formula is for an EF-M 16-80mm f/2-6. This concept definitely fits what would be considered a kit lens.</p>
<p>Patent Publication No. 2016-51137 (Google Translated)</p>
<ul>
<li>Published 2016.4.11</li>
<li>Filing date 2014.9.2</li>
<li>Zoom ratio 4.71</li>
<li>Focal length 16.09 41.83 75.78</li>
<li>F-number 2.07 5.15 6.00</li>
<li>Half angle of view (degrees) 36.26 18.01 10.17</li>
<li>Image height 11.80 13.60 13.60</li>
<li>The total lens length 100.68 110.04 120.89</li>
<li>BF 15.19 27.94 26.84</li>
</ul>
<p>I suspect we’ll be seeing a lot more patents for upcoming EOS M products.</p>
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[Wizardly]

The most confusing thing about this claim is that at the wide end the image height is only 11.8 mm and 13.6 mm (APS-C) at the mid to long end. 11.8 mm is appropriate for a 1.5" type sensor of the G1X cameras.

 

[Sharlin]

Wow, f/2-f/6... that's a pretty huge range.

 

[TWI by Dustin Abbott]

Wow, f/2-f/6... that's a pretty huge range.

Exactly what I was thinking. 3 1/3 stops, roughly. That puppy is going to be a pain to use in manual mode.

 

[ajfotofilmagem]

Zoom aperture F2-6

Must have a very small front element, reason being just F6 when in 80mm.
I suppose it would atrocious vignette in 16mm F2, and may be best to limit the diaphragm F2.4-6. :

Marketing could do rounding of numbers, and label as an F2.4-5.6 lens. 8)

 

[TeT]

Zoom aperture F2-6

Must have a very small front element, reason being just F6 when in 80mm.
I suppose it would atrocious vignette in 16mm F2, and may be best to limit the diaphragm F2.4-6. :

Marketing could do rounding of numbers, and label as an F2.4-5.6 lens. 8)

16-80mm f/2.8-5.6 would be a much more attractive lens;

 

[Random Orbits]

It's probably optimized for small physical size. The native existing M lenses aren't that big... not sure how much can be gained from this...

 

[neuroanatomist]

The most confusing thing about this claim is that at the wide end the image height is only 11.8 mm and 13.6 mm (APS-C) at the mid to long end. 11.8 mm is appropriate for a 1.5" type sensor of the G1X cameras.

Agreed – this seems like a G-series fixed lens patent.

 

[bainsybike]

The most confusing thing about this claim is that at the wide end the image height is only 11.8 mm and 13.6 mm (APS-C) at the mid to long end. 11.8 mm is appropriate for a 1.5" type sensor of the G1X cameras.

Agreed – this seems like a G-series fixed lens patent.

It seems physically very long if so. Compare the EF-M 55-200 at 91.6-132.6mm.

 

[neuroanatomist]

The most confusing thing about this claim is that at the wide end the image height is only 11.8 mm and 13.6 mm (APS-C) at the mid to long end. 11.8 mm is appropriate for a 1.5" type sensor of the G1X cameras.

Agreed – this seems like a G-series fixed lens patent.

It seems physically very long if so. Compare the EF-M 55-200 at 91.6-132.6mm.

You're giving the measured length of the lens, you need to add the flange-focal distance (18mm) to compare to the overall lens length in a patent (which is for the optical formula, so the length starts at the sensor). For the M55-200 that's 109.6-150.6 mm. The total length of a G1XII with lens extended is ~120mm, so the max lens overall length is ~110mm (assuming the sensor is ~1 cm in front of the back of the camera), making a lens patent for a length of 100-121mm pretty reasonable.

The key point is the image height - that's the measurement of the radius of the lens' image circle, and a Canon APS-C sensor needs an image height of 13.4mm to cover the sensor (Canon generally uses 13.66 in designs). This patent with an image height of 11.8mm at the wide end is not big enough for APS-C. The required image height for the 1.5" sensor in the G1XII is 11.7mm.

 

[bainsybike]

Thank you Neuro for a comprehensive and helpful explanation.

 

[FECHariot]

Wow, f/2-f/6... that's a pretty huge range.

When I first read the article, I tricked my mind into seeing a constant aperture 2.6.

2-6 - Ish

 

[okaro]

Concur, length (24-120 equivalent) and the bright side (F/2) match up against the existing G1X II's lens; this may be a refreshed lens for the replacement to the G1X II.

It wouldn't be 24-120 mm equivalent on G1 X sensor. It would start at 31 mm equivalence. Nobody would bring such a camera on the market. Most likely it will be limited to 18-80 mm.

 

[Wizardly]

Concur, length (24-120 equivalent) and the bright side (F/2) match up against the existing G1X II's lens;

1.5" type sensor has a crop factor of 1.92, so it comes closer to 30 - 150 mm.

 

[Mt Spokane Photography]

As is usual with patent, there are several working examples, and Igami picks one for their story.

In this case, there are five working examples, but the patent is for a formula, so the examples are not exclusive. What struck me as unusual is how similar the 5 examples are.

Here is a little more in the patent discussing the concept. Its apparent that they are trying to come up with a small lens for a 1.5 in sensor. Making a G1X camera that is pocketable??

"In recent years, an imaging device is miniaturized and, moreover, the image sensor used for it is enlarged by high sensitivity. It being a large diameter ratio from which an image with shallow (the blur's was emphasized) depth is acquired, and telecentric nature are good for the zoom lens used with an imaging device provided with such an image sensor, and, moreover, it is required that the whole system should be small etc. Attaining large diameter ratio-ization, for attaining the miniaturization of the whole system, it is necessary to make the diameter of a lens barrel small. In order to make the diameter of a lens barrel small, the position of the optical axis direction of a diaphragm unit is set up appropriately, and it is necessary to make it the diaphragm diameter of an aperture diaphragm become small.
[0003]
In order to make the diaphragm diameter of an aperture diaphragm small, having a fixed aperture ratio, it is good to, set the position of the optical axis direction of an aperture diaphragm to the image side if possible of a lens system. Conventionally, an aperture diaphragm is arranged to the image side in a lens system, and the zoom lens which made the path of the diaphragm unit small is known"

Another excerpt:

"An object of the present invention is to provide the imaging device which has the small zoom lens and it from which it is a large diameter ratio, and high optical performance is obtained over all the zoom ranges."


1.
Zoom ratio 4.71
Wide angle Middle Looking far
Focal distance 16.09 41.83 75.78
F number 2.07 5.15 6.00
a half field angle (degree) -- 36.26 18.01 10.17
Image height 11.80 13.60 13.60
Whole length of the lens 100.68 110.04 120.89
BF 15.19 27.94 26.84

2.
Zoom ratio 4.71
Wide angle Middle Looking far
Focal distance 17.94 41.76 84.48
F number 2.94 5.00 6.00
a half field angle (degree) -- 33.34 18.04 9.15
Image height 11.80 13.60 13.60
Whole length of the lens 97.34 108.30 120.68
BF 13.21 25.00 30.35

3.
Zoom ratio 4.71
Wide angle Middle Looking far
Focal distance 16.61 41.76 78.21
F number 2.07 4.64 6.00
a half field angle (degree) -- 35.39 18.04 9.86
Image height 11.80 13.60 13.60
Whole length of the lens 97.81 108.49 120.70
BF 14.83 27.15 26.20

4.
Zoom ratio 4.71
Wide angle Middle Looking far
Focal distance 18.04 41.76 84.96
F number 2.94 5.00 6.00
a half field angle (degree) -- 33.19 18.04 9.09
Image height 11.80 13.60 13.60
Whole length of the lens 96.81 108.02 120.68
BF 11.81 22.76 25.78

5.
Zoom ratio 4.71
Wide angle Middle Looking far
Focal distance 18.17 40.60 85.54
F number 2.10 5.00 6.00
a half field angle (degree) -- 33.01 18.52 9.03
Image height 11.80 13.60 13.60
Whole length of the lens 99.13 109.10 119.77
BF 9.92 17.64 27.15

 

[SwampYankee]

f6??????? I hope this thing costs less than $99 because f6 is is a huge step back. When is the last time a major camera producer had the audacity to release an f6 lens? I think the 1st iphone was faster. Keep ignoring mirroless Canon. lets see how that works out for ya!

 

[neuroanatomist]

f6??????? I hope this thing costs less than $99 because f6 is is a huge step back. When is the last time a major camera producer had the audacity to release an f6 lens? I think the 1st iphone was faster. Keep ignoring mirroless Canon. lets see how that works out for ya!

Oh, like a couple of the existing Canon EF-M lenses, like the Sony 55-210mm, like the Nikon 18-300mm (that's for dSLRs!), all of which are f/6.3 at the long end. They're all current lenses, released in the last few years.

Did you mean more recent? Well, for a mere $1800 (that's just a bit more than $99, I think), you can pre-order the recently announced Leica 100-400mm f/4-6.3 OIS.

If you're going to drip sarcasm and spread scorn, try to get your facts straight first, mmmmmkay? :

 

[Wizardly]

In this case, there are five working examples, but the patent is for a formula, so the examples are not exclusive. What struck me as unusual is how similar the 5 examples are.

Wouldn't a sixth (seventh, eighth, etc...) formula using the same lens 13-lens arrangement (but with different curvatures, thicknesses, abbe numbers, refractive indices, etc...) require a new patent?

 

[Zv]

f6??????? I hope this thing costs less than $99 because f6 is is a huge step back. When is the last time a major camera producer had the audacity to release an f6 lens? I think the 1st iphone was faster. Keep ignoring mirroless Canon. lets see how that works out for ya!

Oh, like a couple of the existing Canon EF-M lenses, like the Sony 55-210mm, like the Nikon 18-300mm (that's for dSLRs!), all of which are f/6.3 at the long end. They're all current lenses, released in the last few years.

Did you mean more recent? Well, for a mere $1800 (that's just a bit more than $99, I think), you can pre-order the recently announced Leica 100-400mm f/4-6.3 OIS.

If you're going to drip sarcasm and spread scorn, try to get your facts straight first, mmmmmkay? :

Tamron 18-200 f/3.5 - 6.3 also comes to mind. There's actually quite a few with f/6.3 at the long end. Seems quite normal. Maybe it's just that f/6 looks strange on paper! We don't usually see it in a f- stop range!