# Patent: Canon 10-120mm f/1.8 Lens for 1\



## Canon Rumors Guy (Aug 16, 2015)

```
A patent showing a Canon 10-120mm f/1.8 lens for a 1″ sensor has become public. Such an optical formula may be a remanent from the XC10 development or could appear in a future video camera product. I’m sure a lot of people would have rather seen an f/1.8 lens in the XC10, instead of the f/2.8 lens it comes with.</p>
<p>Patent Publication No. 2015-75523</p>
<ul>
<li>Published 2015.4.20</li>
<li>Filing date 2013.10.7</li>
</ul>
<p>Example 1</p>
<ul>
<li>Zoom ratio 11.54</li>
<li>Focal length 10.21 56.31 117.88</li>
<li>F number 1.87 1.79 1.78</li>
<li>Half angle (in degrees) 38.07 8.09 3.88</li>
<li>Image height 8.00</li>
<li>Overall length of the lens 555.0</li>
<li>BF 16.56</li>
</ul>
<p>Canon patents</p>
<ul>
<li>5-group zoom of positive and negative TadaS___adaS___adashi</li>
<li>Inner focus (part of the first group)</li>
<li>Inner zoom</li>
</ul>
```


----------



## Mt Spokane Photography (Aug 16, 2015)

With the 2.7 crop factor for a one inch sensor, that's a FOV equivalent to a 27- 324mm FF lens. At f/1.8, that's quite a lens even though it is a small sensor, it will be pretty big and expensive..


----------



## dcm (Aug 16, 2015)

The overall length is around 555mm or about 22 inches. For comparison, the 600F4L is 448mm, the 800f5.6L is 461mm, and the 1200f5.6L is 836mm. That's a pretty big lens and a lot of glass for such a small sensor.


----------



## Mt Spokane Photography (Aug 16, 2015)

dcm said:


> The overall length is around 555mm or about 22 inches. For comparison, the 600F4L is 448mm, the 800f5.6L is 461mm, and the 1200f5.6L is 836mm. That's a pretty big lens and a lot of glass for such a small sensor.



It does sound like a broadcast lens. Many broadcast cameras use 2/3 sensors, so the standard may jump to 1 inch. 

In any event, it sounds pretty amazing, and likely to cost North of $30,000. I realize that not all patents actually result in production. This one is a obvious candidate for a DO treatment.


----------



## lo lite (Aug 16, 2015)

Canon Rumors said:


> positive and negative TadashiTadashiTadashi



What is that?


----------



## keithcooper (Aug 16, 2015)

Note the block at the back of the diagram - quite possibly a 3-way beam splitter for 3-sensor video cameras


----------



## Simen1 (Aug 16, 2015)

Mt Spokane Photography said:


> With the 2.7 crop factor for a one inch sensor, that's a FOV equivalent to a 27- 324mm FF lens. At f/1.8, that's quite a lens even though it is a small sensor, it will be pretty big and expensive..


Note, its not equivalent to a 27-324mm f/1,8 FF lens. It equivalent to a 27-324mm f/4,86 FF lens. Still quite impressive.

Just like my 8-48m f/1,0 lens sounds impressive until i mention its only for 1/3" sensors.


----------



## Digbydriver (Aug 17, 2015)

Sounds like a studio television camera lens to me. I shoot a Fujinon on my ENG camera, a 13x lens.


----------



## Mt Spokane Photography (Aug 17, 2015)

Simen1 said:


> Mt Spokane Photography said:
> 
> 
> > With the 2.7 crop factor for a one inch sensor, that's a FOV equivalent to a 27- 324mm FF lens. At f/1.8, that's quite a lens even though it is a small sensor, it will be pretty big and expensive..
> ...



I did not say the aperture was equivalent, I said FOV (Field of view) However, the Aperture is f/1.8, not f/4. What you are referring to is depth of field calculations. For setting exposure, its still f/1.8.


----------



## Simen1 (Aug 17, 2015)

Mt Spokane Photography said:


> Simen1 said:
> 
> 
> > Mt Spokane Photography said:
> ...


I was referring to DoF, total exposure in terms of # photons in total image, total photon noise in terms of RMS per image size or fraction of image size. I could also include diffraction effects but thats not very prominent in this case.

I know the aperture is focal length / 1,8 but focal length is a smaller number then an equivalent FOV lens for a larger sensor. Thus the absolute aperture is smaller, causing these effects.


----------



## Khufu (Aug 17, 2015)

If I crop away 75% of a Bird in Flight shot, the Bird doesn't get darker.

Correctly metered and focused, an f/1.8 lens projects focused light in the shape of a bird across a few millimetres of an image plane, regardless of what's going on on the rest of the sensor, or if the sensor is even... there.

You could also include your zip code and underwear size but that's only as relevant as all the other redundant data you're bringing to the table... "IMO". 

If you mount this on an a7r it's going to focus just as many photons in the shape of a bird with the same projected dimensions as it would on a 1"-type sensor.


----------



## Khufu (Aug 17, 2015)

Ps. I would LOVE to try this out on the EOS M2 with 3x video crop/zoom...


----------



## LonelyBoy (Aug 17, 2015)

Oh good, an equivalency argument. At least we're discussing fresh topics.


----------



## Etienne (Aug 17, 2015)

It would make a great lens on the XF300 replacement (XF400 ?), assuming they move to a 1" sensor.


----------



## RGF (Aug 17, 2015)

what are the dimensions of 1" sensor? Assuming a 2x3 axial ratio I get 0.55" x 0.83" or 14 x 21 mm.

Is that correct?


----------



## Khufu (Aug 18, 2015)

Frustratingly not; not even close! 13.2mm x 8.8mm is one figure I've just seen. They're really "one inch type sensors", which refers to dimensions of hardware that surrounds old broadcast cameras' captured image plane... (right? Feel free to jump in, if anyone knows the terminology and tech!) Tubes and... analogue... something. Maybe.


----------



## Etienne (Aug 18, 2015)

Khufu said:


> Frustratingly not; not even close! 13.2mm x 8.8mm is one figure I've just seen. They're really "one inch type sensors", which refers to dimensions of hardware that surrounds old broadcast cameras' captured image plane... (right? Feel free to jump in, if anyone knows the terminology and tech!) Tubes and... analogue... something. Maybe.



The 1" sensor is just a little bigger than super 16 film (12.52 x 7.41 mm)


----------



## Mt Spokane Photography (Aug 18, 2015)

RGF said:


> what are the dimensions of 1" sensor? Assuming a 2x3 axial ratio I get 0.55" x 0.83" or 14 x 21 mm.
> 
> Is that correct?



Its a oddball computation, and hardly related to 1 inch.

Wikipedia has a table of dimensions and the history of how they came to be so bollixed up.

They list the Sony 1 inch sensor as being 13.20 X 8.8mm. However, a camera may not use all of the photosites in a sensor, so that can throw off any assumptions.

https://en.wikipedia.org/wiki/Image_sensor_format


----------



## Mt Spokane Photography (Aug 18, 2015)

LonelyBoy said:


> Oh good, an equivalency argument. At least we're discussing fresh topics.



I don't think there is a argument. Most posters here are well aware, just a new member who thinks he has to teach others.


----------



## Khufu (Aug 19, 2015)

Mt Spokane Photography said:


> RGF said:
> 
> 
> > what are the dimensions of 1" sensor? Assuming a 2x3 axial ratio I get 0.55" x 0.83" or 14 x 21 mm.
> ...



I'd assume the dimensions we both mentioned (Sony's?) are too great for this lens to make use of and smaller sizes do indeed get the 1" branding... I've not clicked back to check but I'm pretty sure the patent suggested the projected image's height was no more than 8mm!


----------

