Patent: RF mount super telephoto lenses

canonnews

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Dec 27, 2017
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It seems obvious they are RF patents based on the 31-33 mm back focus distances specified in the patents.

Based on an appropriately-scaled overlay, the second group back from the front element (G1n) sits ~6mm behind the corresponding group in the 600/4 III, and the next group back is ~12mm behind the corresponding EF group.

View attachment 184781
yes, there isn't going to be a significant difference. I'm actually surprised there's ANY difference to a super telephoto, but there it is.

I think you're expecting a lot from a focal length that is supposed to show no benefits for a shorter registration distance.
 
Aug 22, 2010
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yes, there isn't going to be a significant difference. I'm actually surprised there's ANY difference to a super telephoto, but there it is.

I think you're expecting a lot from a focal length that is supposed to show no benefits for a shorter registration distance.
I'm really surprised that Canon haven't gone for DO optics for the RF system. It kind of makes sense making the RF versions shorter and lighter than the EF versions. As it is...there is so little between the EF and RF versions...is there any point other than having a native lens.
 

neuroanatomist

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I think you're expecting a lot from a focal length that is supposed to show no benefits for a shorter registration distance.
I’m not expecting anything. But many on this forum continue to tout the ‘benefits of the RF mount,’ and the ‘smaller, lighter, higher IQ’ lenses that mount makes possible. I have yet to see any evidence of those purported benefits. Claims that are put forward just blow away like smoke in the wind when examined critically, for example 40-50mm becoming 6mm.

The only evident benefit is in terms of lens-body communication, but that has nothing to do with the short flange distance (and after all, even the EF-M mount has two extra pins compared to EF).
 

canonnews

EOS RP
Dec 27, 2017
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I’m not expecting anything. But many on this forum continue to tout the ‘benefits of the RF mount,’ and the ‘smaller, lighter, higher IQ’ lenses that mount makes possible. I have yet to see any evidence of those purported benefits. Claims that are put forward just blow away like smoke in the wind when examined critically, for example 40-50mm becoming 6mm.

The only evident benefit is in terms of lens-body communication, but that has nothing to do with the short flange distance (and after all, even the EF-M mount has two extra pins compared to EF).
yes, sorry, and yeah I agree. seems there was some expectations thrown out there, but really alot of that came from Nikon, not Canon.
 

Kit.

EOS 6D MK II
Apr 25, 2011
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You may be right. This sort of thing has to be done at a fairly slow pace. You don't want to have any abrupt changes that can organize resistance.
If the market shows a clear preference for RF bodes (thus there will be no point in developing new EF lenses), that "slow pace" will happen naturally, just as older lens models are replaced with newer, improved ones. There is no reason for conspiracy.

If the market shows no clear preference, there is no point in crippling RF bodies by intentionally making them incompatible with EF lenses.
 

AlanF

Canon 5DSR II
Aug 16, 2012
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I'm really surprised that Canon haven't gone for DO optics for the RF system. It kind of makes sense making the RF versions shorter and lighter than the EF versions. As it is...there is so little between the EF and RF versions...is there any point other than having a native lens.
There are some drawbacks to DO optics, one being they are more susceptible to flare and lose contrast against strong light. However, if you can't lift the heavier lens the drawbacks are of minor detail.
 

degos

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Mar 20, 2015
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If the market shows no clear preference, there is no point in crippling RF bodies by intentionally making them incompatible with EF lenses.
Hmm, I dunno... you have to think with a corporate group-mind. If the market isn't adopting a New Shiny Thing, that means, in corp-think, that the market is stupid and lazy and needs to be beaten into doing the Right Thing. So I wouldn't be at all surprised if lens-mount interoperability began to 'deteriorate'; maybe IBIS will only work with RF lenses, due to the communication data-rate needed...
 

BillB

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May 11, 2017
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Hmm, I dunno... you have to think with a corporate group-mind. If the market isn't adopting a New Shiny Thing, that means, in corp-think, that the market is stupid and lazy and needs to be beaten into doing the Right Thing. So I wouldn't be at all surprised if lens-mount interoperability began to 'deteriorate'; maybe IBIS will only work with RF lenses, due to the communication data-rate needed...
So, if you build a better mousetrap, you are beating the stupid and lazy market into doing the Right Thing?
 

BillB

EOS 6D MK II
May 11, 2017
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If the market shows a clear preference for RF bodes (thus there will be no point in developing new EF lenses), that "slow pace" will happen naturally, just as older lens models are replaced with newer, improved ones. There is no reason for conspiracy.

If the market shows no clear preference, there is no point in crippling RF bodies by intentionally making them incompatible with EF lenses.
Even if there is a clear preference for RF bodies, there will be a market for EF lenses so long as there are Canon DSLRs, EF mount video cameras, and M mount mirrorless. Maybe Canon might develop new EF lenses for such a market, or maybe not. I am pretty sure they would keep selling EF lenses to anyone who wanted buy one.
 
Aug 22, 2010
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There are some drawbacks to DO optics, one being they are more susceptible to flare and lose contrast against strong light. However, if you can't lift the heavier lens the drawbacks are of minor detail.
Yes I agree....but Canon have also pushed the technology a lot. The 400mm f4 DO II is a lot better optically / back lit contrast than the mkI. So one could assume that an RF version (essentially a mkIII) would be even better. I think I read somewhere on a Canon page that these days they are using 2 or 3 DO optic elements compared to the older single DO element.
 

degos

EOS RP
Mar 20, 2015
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So, if you build a better mousetrap, you are beating the stupid and lazy market into doing the Right Thing?
The question was around what Canon would do if the market didn't rush to the RF mount ( the Better Mousetrap* ).

My conjecture is that they'll see this as a failure on the part of the market, rather than a reflection of the lack of advantage of moving to RF. And will therefore take steps to make EF artificially obsolete in order to force upgrades.

* which itself is actually a sarcastic term referring to an overcomplicated solution to a simple problem
 
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Kit.

EOS 6D MK II
Apr 25, 2011
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Hmm, I dunno... you have to think with a corporate group-mind. If the market isn't adopting a New Shiny Thing, that means, in corp-think, that the market is stupid and lazy and needs to be beaten into doing the Right Thing. So I wouldn't be at all surprised if lens-mount interoperability began to 'deteriorate'; maybe IBIS will only work with RF lenses, due to the communication data-rate needed...
If IBIS only works with RF lenses, people will be less interested in buying RF cameras.

Edited, sorry.
 
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BillB

EOS 6D MK II
May 11, 2017
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If IBIS only works with RF lenses, people will be interested in buying RF cameras.
On the other hand, if your IBIS only works with RF lenses and all the other guys have IBIS that works with whatever you put on the camera, you may want to rethink your strategy.
 

BillB

EOS 6D MK II
May 11, 2017
1,137
379
The question was around what Canon would do if the market didn't rush to the RF mount ( the Better Mousetrap* ).

My conjecture is that they'll see this as a failure on the part of the market, rather than a reflection of the lack of advantage of moving to RF. And will therefore take steps to make EF artificially obsolete in order to force upgrades.

* which itself is actually a sarcastic term referring to an overcomplicated solution to a simple problem
If I recollect correctly, the saying is that if you build a better mousetrap, the world will beat a path to your door. Not saracastic at all.
 
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unfocused

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The question was around what Canon would do if the market didn't rush to the RF mount...

....My conjecture is that they'll see this as a failure on the part of the market, rather than a reflection of the lack of advantage of moving to RF. And will therefore take steps to make EF artificially obsolete in order to force upgrades...
That's both silly and more than a bit paranoid.
 

unfocused

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Does anyone really believe Canon purposely has as one of its goals alienating their customers? I'd suggest the opposite...
Sadly, there are always people who will believe in conspiracies rather than accept a reality that conflicts with their uninformed view of the world.

I've seen this all my life. As a kid growing up in the 60s I had classmates that insisted there was a secret carburetor that could get 100 miles to the gallon, but Detroit and the oil industry had conspired to keep it off the market. I also grew up in an era when people seriously suggested that fluoridated water was a Russian plot to poison American children.

Today we have people who put other people's children at risk by refusing to have their own children vaccinated.

So, when I read some of the ridiculous theories floated on this forum, I cringe, but know that no amount of logic or common sense will change their minds.
 

AlanF

Canon 5DSR II
Aug 16, 2012
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Yes I agree....but Canon have also pushed the technology a lot. The 400mm f4 DO II is a lot better optically / back lit contrast than the mkI. So one could assume that an RF version (essentially a mkIII) would be even better. I think I read somewhere on a Canon page that these days they are using 2 or 3 DO optic elements compared to the older single DO element.
The 400mm DO II does use 2 DO gratings already. The problem is light from the zeroth-order diffraction coming straight through. Nikon have the same problem with their very modern PF lenses.