A hypothesis concerning the RF mount

ahsanford

Particular Member
Aug 16, 2012
8,064
635

3kramd5

EOS 5D MK IV
Mar 2, 2012
3,083
404
Really difficult and expensive to have a moving sensor and keep it parallel to 1/10000 in tolerances. Canon puts shims under each sensor to keep it parallel to the lens mount, its difficult. The shim thickness is marked on the sensor, but a check with a special tool is also a requirement.

View attachment 179997
But that’s for a sensor which doesn’t move. If you can move the sensor, you can align it, in demand, without shims.

I’m not saying that mightn’t be expensive, but it’s doable.
 
  • Like
Reactions: Keith_Reeder

The Fat Fish

VFX Artist
Jul 29, 2017
90
54
26
Exeter, UK
It does not need a "sexy solution" or some overly engineered way of mounting EF lenses. Scrap EF mount in favour of the long term benefits and offer a simple adapter to keep current users as happy as they can.

Awkwardly engineering a mount that is looking to the past and not the future will only end badly.
 
  • Like
Reactions: fullstop

Mikehit

EOS 5D MK IV
Jul 28, 2015
3,253
454
Standard and tele lenses don’t need elements close to the sensor. Wide zooms mostly have narrow rear elements.
But my point was that if we have a deep body with a R lens that sits deep in the mount, if Canon make a slim mirroless later on those deep-sitting rear element will be damned near touching the sensor.
 

3kramd5

EOS 5D MK IV
Mar 2, 2012
3,083
404
But my point was that if we have a deep body with a R lens that sits deep in the mount, if Canon make a slim mirroless later on those deep-sitting rear element will be damned near touching the sensor.
And that’s probably a good thing, optically.
 

ahsanford

Particular Member
Aug 16, 2012
8,064
635
Why do so many people assume this is a do or die situation for Canon. It's entirely possible to have an EF mount now and wait to introduce a new mount later, one that will work with curved sensors or Medium Format sensor. Also these Rube Goldberg shifting sensor mechanisms don't sound so attractive especially since Canon are known for reliability, quality and performance. Keep it simple Canon, EF mount now sit back and plan something truly revolutionary for the next mount.

There's a perception that the near-term is a critical inflection point where Canon needs to get in and stop some ascendant Sony market share phenomenon in the making. As Neuro pointed out, Sony is not winning unit share yet -- they continue to stumble on basics, support, accessories, etc. But few would doubt that their products (with their A7 III generation) are not making strides towards a point where Sony will finally start flipping a lot of professionals and enthusiasts into their ranks.

A poorly spec'd FF mirrorless that either leaves out a critical feature (4K, IBIS, every day more calls for Eye AF, etc.), leaves a big part of the market behind (i.e. full EF vs. thin mount), etc. could be the tipping point that pushes people to Sony -- warts and all. There comes a point that the spec per dollar value proposition is so much better (coupled with finally getting some lenses) and Sony becomes that 6 out of 10 option that is consistently trending upwards enough that folks stop waiting for Canon to give them the camera they want.

Many folks feel that time is now.

I am not one of them, but I also think it's not Canon's MO to stay on the sidelines this long. I don't personally believe an off-target FF mirrorless will be Canon's undoing at all, but a poorly thought through platform could be an anchor around their necks that they might stick with rather than fix (Nikon 1, I'm looking at you).

In short, Canon's greatest threat may not be Sony -- it might be Canon itself. They could end up rocking the boat with a bad major decision on this platform. Don't believe me? When they launch this thing, see how long/often Canon points out that EF is going to work and work perfectly with this new system. They will be reassuring as many people as they are prospectively selling this new system to. They have (in many folks' minds) more to lose than to gain.

But you are right, Canon is absolutely big enough to get this wrong, course correct and get back on track.

- A
 
Last edited:
  • Like
Reactions: shunsai

ahsanford

Particular Member
Aug 16, 2012
8,064
635
But my point was that if we have a deep body with a R lens that sits deep in the mount, if Canon make a slim mirroless later on those deep-sitting rear element will be damned near touching the sensor.

That's fine. They won't do both. They either go full EF with 'stuff-tuckable-insideable' or they offer a thin mount body. Why on earth would they do both? The point of a tuckable-insideable lens mount is to not have to make a thin mount body.

In other words, if they want a thin mount body that requires an adaptor, they just go out and build one and not waste time on a more complicated nested design.

- A
 
Last edited:

Mikehit

EOS 5D MK IV
Jul 28, 2015
3,253
454
That's fine. They won't do both. They either go full EF with 'stuff-tuckable-insideable' or they offer a thin mount body. Why on earth would they do both. The point of a tuckable-insideable lens mount is to not have to make a thin mount body.

- A
Which obviates them from the 'mirorless is small' brigade and commits them to a long line of development. I know you have shown repeatedly the graphic that shows how most lenses will extend beyond the grip, but when packing that camera into the bag.....

It may work, but at worst it echoes Nikon's decision all those years ago to keep with an AF mount that would ensure compatability with existing lenses whereas Canon took the decision to make a complete break. Their market research will be based on what people think they need now and the immediate future. In this respect the slimmer Nikon/Sony mounts offer greater flexibility for the long-term future but Canon are taking a gamble.

Oh, boy, I wonder how many hours they spent discussing this round the Canon boardroom!! And whose neck is on the block.
 
  • Like
Reactions: Keith_Reeder

davidhfe

EOS T7i
Sep 9, 2015
57
27
It does not need a "sexy solution" or some overly engineered way of mounting EF lenses. Scrap EF mount in favour of the long term benefits and offer a simple adapter to keep current users as happy as they can.

Awkwardly engineering a mount that is looking to the past and not the future will only end badly.
Exactly this—there is zero need to add a bunch of moving parts or awkwardly designed lenses to address something that is effectively a non issue. One of the big plusses of mirrorless is that you're removing hardware complexity and putting it into software: No half silvered mirror with an AF module, no prism bouncing light to an AE sensor, etc etc. And everyone who's talking about "but SD cards fail" should be aghast at the idea of a half inch lens elements protruding into a camera or a sensor that shuffles around while somehow retraining registration.

Now is Canon's chance. Sony and Nikon have both demonstrated the engineering benefits and the market acceptance of some sort of mount change/optimization. Do it now and have the EOS mount updated for the next 20 years. Don't kick the can down the road. And unlike Nikon, the "RF" mount can be mechanically and electrically identical to EF—just change the flange distance and, if necessary, the communication protocol while having the body support both.

This body should ideally telegraph the future (or lack thereof in some cases) for EF, EF-M, EF-S, Cine, Cine S, potential medium format, etc or it's just going to keep the market in a state of unease until they do.

Weird engineering hacks (even if they're labeled as sexy) are the last thing needed right now.
 

Kit.

EOS 6D MK II
Apr 25, 2011
1,485
851
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?
Yes. An adapter.

I hope Canon is not that stupid to use mechanically compatible mounts at several different flange distances.
 
  • Like
Reactions: fullstop

jolyonralph

EOS R Mark II
Aug 25, 2015
1,120
351
London, UK
www.everyothershot.com
So it does seem they're not trying to compete with Sony or Nikon but are being more conservative and looking primarily to their existing customer base for this particular product - assuming the rumors are correct.

This may not be a bad thing for them with Nikon aiming directly at Sony with their camera and having a very much more radical redesign on their current DSLRs.

The RF design as proposed above is a workable solution for a body with a native EF mount and no mirror. It allows more compact wide angle lenses particularly but it doesn't really give the same level of compactness that the Sony system (and potentially Nikon) offer. That's a big deal for me, it's probably less of a deal for others.

The question that now interests me is where would Canon fit a mirrorless 7D-class replacement in the lineup? EOS-M class, with EF-M lenses? or an RF mount body with an APS-C sensor? Logically the latter seems more likely but that would lead to a future where even after DSLRs are long gone Canon would still need to make EF-M lenses, EF lenses, RF lenses *and* EF-S lenses. (or possibly RF-S lenses!)

And there's still a (very small) chance that they could launch a FF EOS-M series camera in the future. Potentially this could have an RF to EF-M adaptor and its own range of EF-FM full-frame lenses too.

As someone one said, the great thing about standards is having so many to choose from :)
 

jolyonralph

EOS R Mark II
Aug 25, 2015
1,120
351
London, UK
www.everyothershot.com
But my point was that if we have a deep body with a R lens that sits deep in the mount, if Canon make a slim mirroless later on those deep-sitting rear element will be damned near touching the sensor.
No, because if it's a slim mirrorless using something like the EF-M mount it'd need an adaptor to take RF lenses keeping the distance between sensor and rear element exactly the same.
 

Mikehit

EOS 5D MK IV
Jul 28, 2015
3,253
454
No, because if it's a slim mirrorless using something like the EF-M mount it'd need an adaptor to take RF lenses keeping the distance between sensor and rear element exactly the same.
and back to the discussion we are having now only in reverse...
 

FramerMCB

Canon 40D & 7D
Sep 9, 2014
401
93
52
The new Canon MILC will also have AI and you won't even have to set/change the settings. It will have a direct link to plug into your head.
 

Respinder

5D Mark III
Mar 4, 2012
59
26
I completely understand your point, but in ten years, when most (?) people will have moved to mirrorless (imo), how will people react when they see the limitations of that retro-compatibility? Will people now criticize Canon for that decision?
I'm guessing Canon won't reinvent a completely new mount in just 10 years right?

I'm nowhere near an expert on the subject so keep in mind I'm just speculating here. But I think it's a mistake to limit the future because of the current/past. If Canon keeps that flange distance on their new mount, then every mirrorless camera in the next 20-30 years will be bigger for no reason.
[EDIT] I know size is not the only advantage of mirrorless but for many people, it is one important aspect.
I don’t think that establishing a hybrid solution now would lock Canon into the EF mount for decades to come.

On the contrary - if Canon introduces an “RF” solution, I don’t see why in the future they could release “RF-only” cameras that simply do not accept EF mount.

By allowing both EF and RF as native lenses on the mirrorless solution today, they can enable a much more gradual transition from one lens style to the other and eventually force EF owners onto adapter solutions years from now when everyone has transitioned to the “sharper”, higher-quality RF lenses.
 
  • Like
Reactions: FramerMCB