A hypothesis concerning the RF mount

[ahsanford]

There is nothing in the world to stop Canon from creating an EF mount (or EF-RF mount) slightly smaller than an SL2. Which is pretty tiny.
how much smaller do you really need to go when your lenses are usually pretty large anyways.

And controls go to hell at that size. SL2 is lovely, I'm sure, but I'll take my 5D wheel / grip / buttons over that any day.

- A

 

[Richard CR]

And controls go to hell at that size. SL2 is lovely, I'm sure, but I'll take my 5D wheel / grip / buttons over that any day.

- A

I tend to agree. you need body size to implement a good fit, relaxed controls and good ergonomics.

but keep in mind that "Similar ergonomics to the EOS M50, and slightly larger body than the EOS M50" is being rumored right now.

which may dissappoint some, as this would sound like a full frame entry level camera.

 

[BillB]

And controls go to hell at that size. SL2 is lovely, I'm sure, but I'll take my 5D wheel / grip / buttons over that any day.

- A

Fair enough, but the point is that if you want small, you can go pretty small while keeping the EF mount and avoid adapter hassles

 

[Refurb7]

Keeping the native registration distance of EF lenses sounds like a terrible idea to me. I sincerely hope Canon doesn't do that. It would mean needlessly fatter bodies, etc.

 

[PureClassA]

Native Dual mount capacity would be really something special. I couldn't fully imagine Canon going FF MILC and having to build another entirely new line. I know Others do it, but when you already have the best lenses... you want to find a way to use them. So assuming RF lenses would be smaller and lighter, the dual mount could still accommodate EF. Could the Sensor plane actually be mounted onto a movable structure that would re-position the sensor forward or backward inside the body slightly to accommodate the lens variances between RF and EF? Total BS conjecture but that could be perhaps one way?

 

[Mt Spokane Photography]

mentioning mirrorless would be meaningless to the patent really

while it may not lock out lens designers where the problem may occur is metabones and the like reverse engineering the RF/EF mount to support Sony FE to EF/RF adapters.

It is said by some that faster data transmission speeds are needed to achieve DSLR like focus speeds for Mirrorless, and that the faster data bus speeds are in the Nikon lens. Those speeds could benefit EF as well.

That is probably why we would see the new electronics in mirrorless first.

 

[BillB]

1) MLU + Liveview on an SLR does not allow you to hold the camera up to your eye unless you design a hybrid VF or use some comical eye loupe on the back LCD. In short, this (below) isn't what I want to do as my default shooting posture. It's a nice trick to have, esp. with an articulating screen. But I overwhelmingly prefer the VF and a more stable shooting posture.

View attachment 179995​

2) An SLR design -- even with MLU + liveview -- cannot adapt other people's lenses. You cannot bolt a Nikkor 14-24 2.8 or 105 f/1.4 on an EF mount... but you might be able to with a thin mount.

I take your point that size is (somehwat idiotically) a huge driver for reducing the flange distance. Who wants all the headaches of a new mount to save 1 measly inch? But to say that SLR + MLU can do everything a mirrorless camera can is simply not so.

- A

and one measly inch or the shortest dimension at that.

 

[Refurb7]

Why are you assuming that the flange to focal plane distance needs to be shorter?

I'm assuming that because that's the most sensible design once the mirror is removed. A mirror box space with no mirror is very inelegant.

 

[Richard CR]

2) An SLR design -- even with MLU + liveview -- cannot adapt other people's lenses. You cannot bolt a Nikkor 14-24 2.8 or 105 f/1.4 on an EF mount

i'm confused by your post here, there is most certainly EF to F mount adapters, and EF to OM1/2 and EF to Contax / Yashica and EF to Pentax,etc

 

[colorblinded]

Read this. The forum already beat this up here. Verdict = possible, but complicated.

- A

Ah, fun. Thanks for sharing, wish I had been able to follow/participate in that chat as it was happening.

 

[MikeD]

I'd worry about this too but it occurs to me - we expect the mirror to move hundreds of thousads of times and stay perfectly aligned, so maybe it's not such a big deal (I guess the tolerances are finer with the sensor though). I still doubt the sensor will be mobile in this way though.

Not for mirrorless, only with a DSLR where the focus sensor needs to stay aligned with the mirror then same to the sensor. W/O a mirror and separate focus sensor, the Z alignment of the sensor is not critical as it would be calibrated with every focus.

 

[amorse]

i'm confused by your post here, there is most certainly EF to F mount adapters, and EF to OM1/2 and EF to Contax / Yashica and EF to Pentax,etc

I think that is in reference to only adapting lenses which require longer flange distances to bodies with shorter flange distances. This way the adapter just needs to add some distance between the sensor and the back of the lens. If the mount provides too much flange distance than a lens supports, the adapter will need some optics instead of being a pass through. This is (to my admittedly limited understanding) why EF lenses can be adapted to Sony E mount bodies, but not the other way around.

 

[scottw]

I have had various Canon cameras over the years (my first decent digical camera was a Elph S200 from ~2002), but never got into their DSLRs until the SL2, which I eventually sold to get into their EF-M system. In both cases I'm been using them for video mostly. Though with the M50 I'm taking it out for photos a lot as well. From my perspective it doesn't make a whole lot of sense to basically have an integrated EF to (whatever) adapter on the camera. That would give these new lenses less diameter to do what they need to do. Considering this new lens would need to fit a good chunk of itself into the opening of the EF mount then I'd speculate that these new lenses to not be capable of larger apertures. I'd much prefer they use the EF-M mount (doesn't have to be exactly 35mm FF in size just as their APS-C is 1.6x crop...). Really, the thing I'm personally hoping for is more ergonomic in that it has a fully articulating screen, more customizability, and with the larger sensor of course. After the release of DPAF on the M50 and M100, it seems like the EF-M system is really positioned well to expand. It could certainly be an option to keep things separate, but I'd imagine they only have so many resources to dedicate to each mount. Being able to have more lens options on my M50 and also having a larger sensor camera would be nice (sure, my few EF-M lenses would have to work in a crop mode on this camera but not a huge deal as their intent is to be small and for crop cameras mostly). Edit: Also, keeping the large flange distance basically makes it not ideal for adapting film era glass which is a pretty appealing option with these mirrorless. EF does have it a bit better than some mounts but not ideal (it couldn't adapt things like L39).

 

[ahsanford]

Keeping the native registration distance of EF lenses sounds like a terrible idea to me. I sincerely hope Canon doesn't do that. It would mean needlessly fatter bodies, etc.

^ ^ ^ ^ ^ ^
As much this forum seems to be dominated with fans of Full EF mount for FF mirrorrless, the 'Keep it small' crowd absolutely exists -- and right now, they are the only show in town between the A7/A9/Z6/Z7/Leica M/Leica SL.

- A

 

[SilverBox]

If we look at the Canon cinema cameras the C700 has a "full frame" (38.1 x 20.1 mm) sensor option in EF or PL mount, so we know they can build a mirrorless FF body that can support EF lenses. The PL and the EF mount are nearly the same diameter but on PL the rear element is closer to the sensor, seen below

 

[ahsanford]

i'm confused by your post here, there is most certainly EF to F mount adapters, and EF to OM1/2 and EF to Contax / Yashica and EF to Pentax,etc

Forgive me, I always thought EF and F were sufficiently close on flange distance that adapting would be impossible. (Aren't they only a couple mm apart?)

- A

 

[traveller]

I'm assuming that because that's the most sensible design once the mirror is removed. A mirror box space with no mirror is very inelegant.

Im not going to pretend that I’m an optical designer, so I’ll just point to some links that might show other benefits of a short flange-back design:

https://www.the-digital-picture.com/News/News-Post.aspx?News=27468

https://diglloyd.com/

 

[Mikehit]

I'm sceptical of this EF-depth body with R-mount lenses that sit deep in the body. This suggests the mount is offset part way up the lens barrel.
In addition, those R-mount lenses intended for this first-generation mirrorless will have an outer barrel thin enough to go through the EF mount which means that they will be narrower lens elements than native lenses.

As and when Canon go full-bore mirrorless in 5-10 years time and start to make bodies that are thinner and lighter, I presume they will have a full-on 54mm R mount and Canon will have to design a whole new set of R-mount lenses - and the lenses they buy now will not be compatible with the future mirrorless body.

Or am I missing something?

 

[Tom W]

Maybe I'm not understanding the hypothesis (I'm slow, give me a break)... How would the flange difference be rectified? If there is no flange difference, than what benefit could there be in switching mounts? Or is the hypothesis that the mount would be switched and the camera can support two protocols?

My hypothesis, FWIW, and based on the limited information we've seen here, is that there is some type of automatic flange extension that pushes out the required 1/4 to 1/2 inch when an EF lens is mounted, but locks in the recessed position when it is an "R" lens.

Seems complicated, but maybe.

 

[ahsanford]

My hypothesis, FWIW, and based on the limited information we've seen here, is that there is some type of automatic flange extension that pushes out the required 1/4 to 1/2 inch when an EF lens is mounted, but locks in the recessed position when it is an "R" lens.

Seems complicated, but maybe.

Is allllll that trouble worth a measly 1/4-1/2"?

I need something sexier than that to sign up for all his trouble. Faster than ring USM on SLR focusing. A modern 50 prime to go on that new mount. Something.

- A