# Patent: EF-M 70-400 f/4.5-7.2 STM



## Canon Rumors Guy (Dec 10, 2014)

```
<p>A patent for a new supertelephoto zoom optical formula for the EOS M system has surfaced in the form of an EF-M 70-400 f/4.5-7.2 STM.</p>
<ul>
<li><strong>Patent Publication No. 2014-228734 (Google Translated)</strong>
<ul>
<li>Published 2014.12.8</li>
<li>Filing date 2013.5.23</li>
</ul>
</li>
<li>Example 3
<ul>
<li>Zoom ratio 5.58</li>
<li>The focal length f = 69.59-251.52-388.00mm</li>
<li>Fno. 4.68-6.30-7.00</li>
<li>Half angle ω = 11.11-3.11-2.02 °</li>
<li>Image height 13.66mm</li>
<li>Overall length of the lens 155.01-227.97-240.02mm</li>
<li>BF 15.81-37.15-46.87mm</li>
<li>Inner focus</li>
</ul>
</li>
</ul>
<p>Source: [<a href="http://egami.blog.so-net.ne.jp/2014-12-10" target="_blank">EG</a>]</p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>
```


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## HaroldC3 (Dec 10, 2014)

Please tell me they aren't developing this lens...I thought 6.3 on the long end was bad enough but 7.2 is not good.


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## neuroanatomist (Dec 10, 2014)

Agree that f/7.2 isn't great, especially for APS-C. The retracted lens is 6" long, not bad for a zoom that goes to 400mm. 

I wonder if this will be sold in the US?


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## dcm (Dec 10, 2014)

Trying to imagine BIF with this lens on an M


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## hoodlum (Dec 10, 2014)

At least this would suggest Canon is working on a more serious EOS M body with built-in EVF.


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## 9VIII (Dec 10, 2014)

Looks like a great lens.

This should be amazing compared to the small aperture and manual focus mirror lenses out there.


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## Tyroop (Dec 10, 2014)

I agree with hoodlum. I was using my EF 400mm f/5.6L recently with the EOS M, and holding the combination at arm's length to compose and focus really isn't ideal. With long lenses you need to brace the camera and get it up to eye level. An EVF option would be a lot better.

Regarding Neuro's comment about being able to buy it in the States if it materialises, I simply can't understand Canon's marketing strategy. I am a big fan of the EOS M, but living in southern Thailand I was unable to get hold of the EF-M 11-22mm and had to drive down into Malaysia, where it is sold, to buy one.

So far, I haven't seen the EF-M 55-200mm in this region at all, although it is a lens I would probably buy if I could get hold of it. I can't understand why certain products are only sold in certain regions when people who live in the 'wrong' places want to buy the products.

Regarding this new EF-M 70-400 patent, it isn't something that interests me greatly. I am happy to have two systems for different needs. I use the EOS M for everyday use and street photography - no great speed or incredibly quick focusing required. I use it for everyday photos of the kids and photos for my website.

Occasionally, if I get the chance, I might go out birding with a long lens, but then I will want the speed and focusing capabilities of a DSLR system. Different tools for different jobs because no one camera system is suitable for every occasion.

These days, the lens that stays on my M most of the time is the 11-22mm. I love the wide angle, but there are also times when I could use a bit more focal length. An EF-M lens that starts off at 10mm or 11mm and extends to around 100mm would be ideal. Any lens over 200mm doesn't really interest me for the current M.

If it was made more like a DSLR - EVF, responsive, fast focusing, etc - it might be a different story, but so far no M body like that exists.


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## Jamesy (Dec 10, 2014)

It is encouraging to see more development of the M system by Canon - I can't wait to see what the M3 will bring. The BMW version was nice so I am expecting BIG things from Canon ;D


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## marchjohn (Dec 10, 2014)

When do you think we are going to see this next M camera?

I really want to buy it!

PS: how can I change the camera listed under my username? I don't even own a SX60 HS


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## WoodyWindy (Dec 10, 2014)

Did anyone besides me notice what was NOT on this lens? Namely Image Stabilization. Could this possibly imply some form of in-body stabilization for the next M?


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## Antono Refa (Dec 10, 2014)

I guess Canon realizes EOS M owners want small lenses, and is considering making tele lenses slow to get there.

That, or Canon just beefs up it's IP portfolio.


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## AvTvM (Dec 10, 2014)

Not interested in the lens, but i also take it as a sign, that a samsung NX1-style EOS-M "Pro" is coming. Evf, good af, good performance, 7d II sensor plus larger body, better grip for all those whining about mirrorless cameras being "too small to handle". ;D

I still predict 2, maybe even 3 new M bodies:
• eos m "pro" - samsung nx1/fuji xt1 competitor
• eos m3 - upgrade from m2 - as small as possible, no evf
• eos m3 "plus" - sony a6000 competitor, small, with evf
All three would sell well ... If specced abd proced competitively.
If indeed released ... End of dslr rebels imminent


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## bf (Dec 10, 2014)

I could not find it with Google patent search. Where do they patent it?


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## Maximilian (Dec 10, 2014)

An EF-M with that focal length and no IS?
Seems strange to me.

and an F7.2? Phew! Not my world.

Maybe there is something else with IS and with some F6.3...


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## dufflover (Dec 10, 2014)

Whilst the f-number itself is not a fixed step thing, it is when it comes to a setting on Canon cameras, so I would expect such a lens (highly doubt it'll get developed) would have a max zoom aperture setting of f/8?

I've had similar (unwieldy/bad) experiences with using an M with longer lenses at arms lengths, however using long lenses with the 70D swivel screen and DPAF is quite nice for low angle and decent enough for static subjects, obviously not BiF. Both features something the next EOS-M everyone expects after the DPAF tech was released (ok ok so the M2 didn't do much lol).

For whatever reason there is something worth patenting in there ...


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## AvTvM (Dec 10, 2014)

bf said:


> I could not find it with Google patent search. Where do they patent it?



Japan? -> cr quotes Egami as source: http://egami.blog.so-net.ne.jp/2014-12-10


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## baervan (Dec 10, 2014)

Not interested in this lens at all, but it then means that the system is alive!  cross fingers for the next M!


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## Chapman Baxter (Dec 10, 2014)

I'll be interested to learn the price of this lens. I contemplated getting the EF-M 55-200mm but I think it's very overpriced (in the UK at least). I ended up getting an EF-S 55-250mm for less than half the price of the EF-M,, to use specifically to use with the M. (I have a 70-200mm ii but the weight of that would defeat the lightweight purpose of the system).


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## lw (Dec 10, 2014)

People are adding 2 and 2 together and making 5.

This is a patent for the optical design of a lens. Not a spec for a product.
Hence it isn't that significant that it doesn't appear to have IS. It is just a patent.

Nor anywhere in the patent does it even mention an EF-M mount or the EOS M system - its just a patent, not a product...

Only the rumour sites are putting 2 and 2 together and deciding it might be an EF-M lens.

It may be true of course - but folks need to remember, its just a patent.


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## NorbR (Dec 10, 2014)

Where does that 7.2 even come from? The actual f-number mentioned in the patent is 7.0, and the more traditional 1/3-stop denomination would be 7.1 (although usually manufacturers tend to round *down* rather than up of course ... I wouldn't even be surprised to see Canon round 7.0 down to 6.3)

In any case, always good to hear mentions of new EF-M lenses, but this is not something that interests me much at first glance. Nothing against slow tele lenses in general, but 200mm is long enough and hard enough to handle on the M, I can't imagine having much use and/or much fun with 400mm ...


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## neuroanatomist (Dec 10, 2014)

lw said:


> Nor anywhere in the patent does it even mention an EF-M mount or the EOS M system - its just a patent, not a product...
> 
> Only the rumour sites are putting 2 and 2 together and deciding it might be an EF-M lens.



The image height and backfocus distance listed in the patent make it pretty clear it's an EF-M lens.


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## Maximilian (Dec 10, 2014)

lw said:


> People are adding 2 and 2 together and making 5.
> 
> This is a patent for the optical design of a lens. Not a spec for a product.
> Hence it isn't that significant that it doesn't appear to have IS. It is just a patent.
> ...


Hi lw! 

Sorry to correct your math a little bit. I am sure the people, that studied this patent did a right "2+2=4".

You are right, that this is JUST a patent and therefore it is not yet any product or ever will be.
But the conclusions from this patent that it would be EF-M, that it has no IS and so on are easy to make (compare to former patents and speculations on it):
1. IS: an IS is a relevant part of the optical formula and therefore appears in the patent text and drawing.
2. Information like image height, distance to image plan (IP in the drawing), back focus (BF) and so on clearly can define, 
if a patent is for EF (FF), EF-S or EF-M (both APS-C, but different distance to IP). 

So people who are familiar to optics can say: "This will be an EF-M".
And then it’s up to logic: Do you believe an EF-M tele zoom lens will be an "L" or will have "ring USM"?
And now you've found the reason for STM driven AF.

Maybe something is translated or calculated wrong (see here aperture of 7.0 to 7.2) but everything else is almost clear.

So the one question left will be: Will this become a product or not?
Here I'd say "No!" I don't believe it, due to the missing IS, which I cannot find in drawing or text.


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## lintoni (Dec 10, 2014)

lw said:


> People are adding 2 and 2 together and making 5.
> 
> This is a patent for the optical design of a lens. Not a spec for a product.
> Hence it isn't that significant that it doesn't appear to have IS. It is just a patent.
> ...


The source for the info states that is EF-M. Patents for lenses that have IS show that it is an IS lens (check rumours and patents for eg the recent 100-400L). This site is called Canon _Rumors_, hence a lot of speculation and guessing are to be expected.


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## jasny (Dec 10, 2014)

Could you point me to the source of this patent? Both CR and Egami present only excerpt. It says "Example 3". So what are other examples? I'm interested only in numbers, don't care if it is in japanese.


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## jasny (Dec 10, 2014)

Maximilian said:


> Here I'd say "No!" I don't believe it, due to the missing IS, which I cannot find in drawing or text.



Apart from the possibility that IBIS body is coming…  Surely IBIS makes more sense in mirrorless than in DSLR (image stabilisation in EVF).


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## neuroanatomist (Dec 10, 2014)

jasny said:


> Maximilian said:
> 
> 
> > Here I'd say "No!" I don't believe it, due to the missing IS, which I cannot find in drawing or text.
> ...



Maybe it's a lens for the Sony E-mount...


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## jasny (Dec 10, 2014)

neuroanatomist said:


> jasny said:
> 
> 
> > Maximilian said:
> ...



Probably  Speaking of probability, IBIS from Canon is close to 0...


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## lw (Dec 10, 2014)

neuroanatomist said:


> The image height and backfocus distance listed in the patent make it pretty clear it's an EF-M lens.



But to be clear, the Patent says

_The present invention is suitably used as an imaging optical system of imaging devices, such as a video camera, a digital still camera, a surveillance camera, a camera for films, and a camera for broadcast, concerning the imaging device which has a zoom lens and it. _

It doesn't even say it is for an interchangeable lens camera, yet alone an EF-M mount...

It could be. But equally, it could not.


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## lw (Dec 10, 2014)

lintoni said:


> The source for the info states that is EF-M.



No. The *source *is the patent filling. The patent says nothing about EF-M.

_Rumour _sites added the EF-M

(sorry for being pedantic.  But until it is a product rumour, not just a patent filing, I am not holding my breath)


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## e17paul (Dec 10, 2014)

HaroldC3 said:


> Please tell me they aren't developing this lens...I thought 6.3 on the long end was bad enough but 7.2 is not good.



This will be a great lens for a sunny day in the countryside. Yes, I know it will need good light, but we can still have our f/4, f/2.8 and faster for when the occasion demands it.

Let's have both options, providing that it has IS and IQ is up to the standard of recent Canon STM lenses.


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## lw (Dec 10, 2014)

BTW, the patent does cover IS, though I am not exactly sure what it is implying!

[0039]
_It may be made to correct image blur when a part of any lens group or lens group is moved so that it may have a vertical component to an optic axis, and a zoom lens vibrates in each working example. According to this, the whole optical system can be prevented from being able to perform vibration control, without newly adding the lens group for optical members, such as a variable vertex angle prism, or vibration control, and being enlarged._

What is meant by _"the whole optical system can be prevented from being able to perform vibration control"_ for example?


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## iron-t (Dec 10, 2014)

I have an EOS-M and enjoy it, but have no interest in this lens with the current body. The only uses I can think of for it are pretty pervy; i.e., grainy (high ISO) surveillance/PI shots or beach candids - and in the latter case good luck composing on the LCD in bright sunlight because you are shooting blind. If the new EOS-M has an EVF, greatly improved focusing (especially servo) and some kind of hand grip, on the other hand, this could be a great lens for casual wildlife use.

I really hope my prediction about the next EOS-M--that it will be essentially a reduced-depth Rebel body with an EVF and the 70D (or other DPAF) sensor--comes true.


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## TWI by Dustin Abbott (Dec 10, 2014)

I can speak from experience of testing lenses (native mount) on the telephoto end on the EOS M that this is all pointless unless they come up with a revised viewfinder system. The combination of glare in daylight (and the narrow aperture of this lens makes daylight shooting pretty much a must) and the disconcerting situation of trying to deal with screen refresh on the LCD makes shooting telephoto of anything moving a nightmare on the current M.

I like the overall concept, but for such a lens to become reality an improved body would first have to come. Someone mentioned that this lens would probably end up coming to market as f/6.3 (marketed maximum aperture) and I agree. Manufacturers tend to fudge these numbers a bit, and truthfully, most of us don't really know the difference when it comes to actually shooting.


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## jasny (Dec 10, 2014)

lw said:


> BTW, the patent does cover IS, though I am not exactly sure what it is implying!
> 
> [0039]
> _It may be made to correct image blur when a part of any lens group or lens group is moved so that it may have a vertical component to an optic axis, and a zoom lens vibrates in each working example. According to this, the whole optical system can be prevented from being able to perform vibration control, without newly adding the lens group for optical members, such as a variable vertex angle prism, or vibration control, and being enlarged._



May I ask you where this text comes from? I can't find it


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## neuroanatomist (Dec 10, 2014)

lw said:


> neuroanatomist said:
> 
> 
> > The image height and backfocus distance listed in the patent make it pretty clear it's an EF-M lens.
> ...



Rather pointless pedantry, as 'stock language' like that is present in many Canon lens patents, including some that became EF and L lenses.


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## lw (Dec 10, 2014)

neuroanatomist said:


> Rather pointless pedantry, as 'stock language' like that is present in many Canon lens patents, including _some _that became EF and L lenses.



_some _being the operative word 

Where is the http://www.canonrumors.com/2014/04/patent-ef-m-22-46mm-f3-5-5-6/
or http://www.canonrumors.com/2014/01/patent-ef-m-18-40-pancake/
or http://www.canonrumors.com/2013/12/patent-16-120mm-f3-5-5-6-is-stm/
or http://www.canonrumors.com/2013/02/patent-canon-ef-14-f2-8-with-flourite/

all of which are claimed as patents for EF-M lenses

Yet none of the lenses they have released since the EOS M's launch have any corresponding patent filing...
Where is the patent filing for the EF-M 11-22, or EF-M 55-200 ?


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## lw (Dec 10, 2014)

jasny said:


> lw said:
> 
> 
> > BTW, the patent does cover IS, though I am not exactly sure what it is implying!
> ...




The patent filing


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## bf (Dec 10, 2014)

lw said:


> jasny said:
> 
> 
> > lw said:
> ...



Can you share the link?


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## lw (Dec 10, 2014)

bf said:


> Can you share the link?



You need to go to the Japanese Patent Database, and search on the patent number
http://www4.ipdl.inpit.go.jp/Tokujitu/tjsogodben.ipdl?N0000=115


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## mavfan1 (Dec 10, 2014)

HaroldC3 said:


> Please tell me they aren't developing this lens...I thought 6.3 on the long end was bad enough but 7.2 is not good.


 It's plenty good enough for daylight wildlife photography. Don't want it? Don't buy it!


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## neuroanatomist (Dec 10, 2014)

lw said:


> _some _being the operative word
> 
> Where is the...
> 
> ...



Obviously not all patents become products, nor are all products preceded by a patent. That's true across all industries.


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## AvTvM (Dec 10, 2014)

mavfan1 said:


> HaroldC3 said:
> 
> 
> > Please tell me they aren't developing this lens...I thought 6.3 on the long end was bad enough but 7.2 is not good.
> ...



yea ... but with the current EOS-M bodies you'll first need to use a tranquilizer gun on the wildlife ...  ;D
well, for zoo animals dozing in bright sunshine it should be sufficient ...


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## jefflinde (Dec 10, 2014)

I really hope this lens gets made. I think it is the perfect addition to the current line up. if i wanted a really fast super-tele lens i would get one of the numerous existing lenses. but for people who use the M as it is intended this lens would be great. Let face it, the M is not a DSLR replacement but a camera to expand the capabilities of point and shoots.


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## MrMeursault (Dec 10, 2014)

Does this mean future EF-M cameras will be able to competently autofocus to f/8. Does this mean I will be able to use my 600mm f/4 (ok I don't really own it) with 2.0x teleconverter on an APS-C mirrorless style body (with adapter of course) for a 1920mm effective field of view?


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## neuroanatomist (Dec 10, 2014)

MrMeursault said:


> Does this mean future EF-M cameras will be able to competently autofocus to f/8. Does this mean I will be able to use my 600mm f/4 (ok I don't really own it) with 2.0x teleconverter on an APS-C mirrorless style body (with adapter of course) for a 1920mm effective field of view?



No mirror means no dedicated phase AF sensor. DPAF works at f/11 (f/5.6 lens + 2x TC).


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## mackguyver (Dec 10, 2014)

f/7.2 @ 400mm (640mm effective FL), apparently with no IS, using the LCD as a viewfinder, all while holding a small body at arms length. 

That doesn't sound like a good idea to me...


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## dcm (Dec 10, 2014)

neuroanatomist said:


> Agree that f/7.2 isn't great, especially for APS-C. The retracted lens is 6" long, not bad for a zoom that goes to 400mm.
> 
> I wonder if this will be sold in the US?



The retracted EF-M 55-200 is 4" long and f/6.3 at 200 so this would be quite a feat. Appears they kept the size down to fit with the style of the M, this could be real interesting if its a similar price. As others have noted, you really can't handhold this on the current body anymore than you can with any other long lens. Hopefully this is the harbinger of a new body with some type of view finder and better autofocus capabilities.


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## dcm (Dec 10, 2014)

BTW: the patent also includes some other variations: a pair of 55-250mm f/4.7-6.5 and a 55-300mm f/4.7-6.5 that are closer to the 4" length of the 55-200mm when closed and 6"-7" extended.


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## AvTvM (Dec 11, 2014)

Exactly. One of the many advantages of mirrorless systems.
Equally important: an electronic viewfinder displays a visible image to look at even in very low light and at f/8 or f/11 ... as opposed to optical viewfinders. In conjunction with ever better hi-ISO capable sensors mirrorless cameras are already expanding imaging capabilities beyond what is possible with mirrorslapping cameras.

Samsung NX1 is a good example for that. At 15fps it is faster than the 7d ii, has a better sensor, and the on-sensorhybrid AF-system appears ti be at least on par with 7d ii as well. Just wait a little until the announced samsung 300/2.8 becomes available and possibly tele-extender 2.0x .. We are lokoing at the first mirrorless entries that are vapable to challenge, match and soon surpass DSLRs in the very field of photography that naysayers eanted to make us believe mirrorslappers could not be beat for many years to come: fast action, long tele stuff, wildlife, air shows, BIF ...

More mirrorless goodness is in the pipeline ... Sony A9 ... might be really really good. Looking forward to see what comes next.


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## mangobutter (Dec 11, 2014)

I don't understand the need or obsession with an EVF on a camera like the EOS M. I'd never use it. No way I'm holding a tiny slippery rectangle shaped camera up to my eye. It wouldn't help much. Just brace yourself if you need stability. If I'm going through all the trouble to hold a camera up to my face and suddenly appear to everyone that I'm taking a picture, then i've defeated the whole point of owning such a camera. I absolutely love the EOS M the way it is and I always hand hold pics shot with my 70-200 F4 on the M @ 200mm (320mm). They come out pretty sharp. I'll attach some casual shots.

These are Facebook compressed photos, mind you. The actual versions are much sharper:


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## AvTvM (Dec 11, 2014)

nice pics. But I don't think the subjects in either of the 2 images would have behaved differently had you taken the camera to the eye to capture the image. ;D

And even when a digital camera does has a viewfinder, there is no obligation to use it for every capture. One can still stick with LCD and "stretched-out arms snapshooter salute".


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## slclick (Dec 11, 2014)

I just noticed B&H has the EF-M adapter kit discontinued and that they are selling the adapter alone on sale in a white box only. I've seen subtler signs of a big change!


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## neuroanatomist (Dec 11, 2014)

slclick said:


> I just noticed B&H has the EF-M adapter kit discontinued and that they are selling the adapter alone on sale in a white box only. I've seen subtler signs of a big change!



Various flavors of EOS M kits have been discontinued and then relisted at B&H for a couple of years now.

A while back, Amazon UK had the 6D listed as discontinued.


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## slclick (Dec 11, 2014)

neuroanatomist said:


> slclick said:
> 
> 
> > I just noticed B&H has the EF-M adapter kit discontinued and that they are selling the adapter alone on sale in a white box only. I've seen subtler signs of a big change!
> ...



Good point, thanks


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