July 21, 2018, 11:51:04 AM

Author Topic: EF-X Mirrorless concept  (Read 6085 times)

BillB

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Re: EF-X Mirrorless concept
« Reply #90 on: July 09, 2018, 04:26:35 PM »
Again, on the original topic of the mount, I am skeptical Canon will go for some transformer/telescoping mount.  I'm also skeptical Canon will pursue the EF-X concept listed here as I honestly believe they will turn off the 'keep it small' crowd with that move.

Like it or not, pragmatism be damned, I think Canon is going thin mount and small with one of its first offerings to court the 'keep it small' crowd.

- A

Fair enough.  Nice hedge--"one of the first" is hard to bet against.  Some of it depends on how small they can get while still using the EF mount.  How much market space is there between the smallest possible EF fullframe and the M5?  And how would the smallest possible Canon EF FF stack up against the A7 III or the Nikon whatever in the smallness wars?  Canon trusts its market research whatever the internet buzz.  If they do go "Super M" with a Fullframe EF-M mount camera, my guess is there will be a 24-70 f4, a prime or two, maybe a spiffed up adapter, and then maybe a 16-xx f4 down the road a bit, and not much more.  Late thought--are we sure that the 32mm EF-M is aps-c?  :)

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Re: EF-X Mirrorless concept
« Reply #90 on: July 09, 2018, 04:26:35 PM »

ahsanford

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Re: EF-X Mirrorless concept
« Reply #91 on: July 09, 2018, 05:13:15 PM »
Late thought--are we sure that the 32mm EF-M is aps-c?  :)

Yes, for three reasons:

1) 32mm screams crop as it's 'Canon crop speak' for a 50 prime.  Why would they avoid the classic 24, 35, 50 increments on that one for FF?

2)  The 35L II already exists.

3)  The non-L 35 f/2 IS already exists.

- A

BillB

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Re: EF-X Mirrorless concept
« Reply #92 on: July 09, 2018, 05:53:14 PM »
Late thought--are we sure that the 32mm EF-M is aps-c?  :)

Yes, for three reasons:

1) 32mm screams crop as it's 'Canon crop speak' for a 50 prime.  Why would they avoid the classic 24, 35, 50 increments on that one for FF?

2)  The 35L II already exists.

3)  The non-L 35 f/2 IS already exists.

- A

But it would be so cool to roll out a "Super M" FF EF-M mount camera with a lens that could be used as a 32mm on FF Super M and as a 50mm equivalent on plain old fashioned aps-c M cameras.  A natural followon would be a 50mm EF-M usable on FF Super M that could be used as 80mm equivalent on aps-c.  What if it turned out that the 22mm EF-M has had a FF image circle all along!

(And either of the EF 35's would need an adapter, which would annoy the small is beautiful crowd.)

3kramd5

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Re: EF-X Mirrorless concept
« Reply #93 on: July 09, 2018, 06:03:54 PM »
Again, on the original topic of the mount, I am skeptical Canon will go for some transformer/telescoping mount.  I'm also skeptical Canon will pursue the EF-X concept listed here as I honestly believe they will turn off the 'keep it small' crowd with that move.

Like it or not, pragmatism be damned, I think Canon is going thin mount and small with one of its first offerings to court the 'keep it small' crowd.

- A

I agree with you about the telescoping Mount... imagine what happens with a big white attached? Also, how do you seal it? What about the contacts?  This is most definitely not an elegant solution

You could do it with a deploying wire harness, but it would be needlessly complicated. Sounds like a cool patent but I’ll be shocked to see it go anywhere.

ahsanford

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Re: EF-X Mirrorless concept
« Reply #94 on: July 09, 2018, 06:04:18 PM »
But it would be so cool to roll out a "Super M" FF EF-M mount camera with a lens that could be used as a 32mm on FF Super M and as a 50mm equivalent on plain old fashioned aps-c M cameras.  A natural followon would be a 50mm EF-M usable on FF Super M that could be used as 80mm equivalent on aps-c.  What if it turned out that the 22mm EF-M has had a FF image circle all along!

(And either of the EF 35's would need an adapter, which would annoy the small is beautiful crowd.)

Lenses that will cover FF image circles -- at those speeds especially -- will be lead pipe pickle jars.  I'm not sure what the appetite for this (see pic) would be for the EOS M crowd.  Your hands would have zero finger room (probably worse than A7 + GM lenses) and you'd be packing a ton more weight than you need to.

That said: I'm sure the IQ from the center of that image circle would be something ridiculous.

- A
« Last Edit: July 09, 2018, 06:10:30 PM by ahsanford »

ahsanford

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Re: EF-X Mirrorless concept
« Reply #95 on: July 09, 2018, 06:09:17 PM »
Sounds like a cool patent but I’ll be shocked to see it go anywhere.

In my line of work, it's the very definition of my management saying "Wow.  That's... wow.  Go patent that concept immediately exactly as it is today -- unsolved problems, warts and all -- and please promptly move on to more practical solutions." 

Translation:  we should bank this innovation so we never get scooped on the idea by a competitor, but there's no way in hell I'm letting you take the time to climb Mt. Awful to sort out all the major issues I can immediately see.  I'd like to see this new product before I retire, and I'm not sure this one will fit that timeline.   ;D

- A

BillB

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Re: EF-X Mirrorless concept
« Reply #96 on: July 09, 2018, 06:10:57 PM »
But it would be so cool to roll out a "Super M" FF EF-M mount camera with a lens that could be used as a 32mm on FF Super M and as a 50mm equivalent on plain old fashioned aps-c M cameras.  A natural followon would be a 50mm EF-M usable on FF Super M that could be used as 80mm equivalent on aps-c.  What if it turned out that the 22mm EF-M has had a FF image circle all along!

(And either of the EF 35's would need an adapter, which would annoy the small is beautiful crowd.)

Lenses that will cover FF image circles -- at those speeds especially -- will be lead pipe pickle jars.  I'm not sure what the appetite for this (see pic) would be for the EOS M crowd.  Your hands would have zero finger room (probably worse than A7 + GM lenses) and you'd be packing a ton more weight than you need to.

- A

Well, they could use STM instead of USM for starters, and you wouldn't need to use retrofocus... :)

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Re: EF-X Mirrorless concept
« Reply #96 on: July 09, 2018, 06:10:57 PM »

3kramd5

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Re: EF-X Mirrorless concept
« Reply #97 on: July 09, 2018, 06:24:32 PM »
So, what would be the aps-c equivalent of a 50mm lens set to f4.0 in terms of framing, light gathering and DOF?

50mm f/4 FF would be the same...

  • Framing and DOF as a 32mm* f/2.8-ish lens on crop (it's not exactly one stop, that's just a rough rule of thumb)
  • Light gathering / exposure as any f/4 lens on any sensor.  Sensor size doesn't change how aperture gathers light.

*Canon and Nikon have different APS-C crop, so it varies a bit.


But because light gathering and DOF do not work the same way w.r.t. equivalence, there is no perfectly equivalent situation.

(Someone straighten me out if I've misread that.)

- A

Sensor size doesn’t affect how the aperture gathers light, naturally.

But f/4 on a 50mm lens is not the same as f/4 on a 32mm lens. The former has more than double the physical aperture diameter, and will transmit less light. You need to stop the shorter lens up to about f/2.6 to get that ~120mm2 opening, which with the same FOV will transmit the same light volume.
« Last Edit: July 09, 2018, 06:27:18 PM by 3kramd5 »

ahsanford

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Re: EF-X Mirrorless concept
« Reply #98 on: July 09, 2018, 06:36:24 PM »
Sensor size doesn’t affect how the aperture gathers light, naturally.

But f/4 on a 50mm lens is not the same as f/4 on a 32mm lens. The former has more than double the physical aperture diameter, and will transmit less light. You need to stop the shorter lens up to about f/2.6 to get that ~120mm2 opening, which with the same FOV will transmit the same light volume.

Which is why all discussions on equivalence lead to thread plague.   ;D

Point taken, but let's please move back on topic.

- A

docsmith

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Re: EF-X Mirrorless concept
« Reply #99 on: July 12, 2018, 11:25:43 AM »
Again, on the original topic of the mount, I am skeptical Canon will go for some transformer/telescoping mount.  I'm also skeptical Canon will pursue the EF-X concept listed here as I honestly believe they will turn off the 'keep it small' crowd with that move.

Like it or not, pragmatism be damned, I think Canon is going thin mount and small with one of its first offerings to court the 'keep it small' crowd.

- A


Agreed....if we go thin (flange distance less than 44 mm) then "EF-X" still is needed, as we will need a FF image circle coming from a lens with a shorter flange distance.
  So, what I think will happen is that Canon will not want to limit their future camera body sizes to fit lenses designed for a mirror box that is no longer needed.  I expect 3-4 "EF-x" lenses to be introduced with a FF mirrorless camera.


But...let me get your opinion on this as a "sexy" and "elegant" solution.  The Canon FF mirrorless entry has a shorter flange distance, but has a built in lens element in the camera body that takes the EF image circle and broadens it to fit a FF image sensor in a distance of less than 44 mm.


So, say a 25-30 mm flange distance, so still more compact, but enough room for that lens element.  We would no longer remove a lens and see the sensor, rather we'd remove the lens and see some glass.


Has this already been suggested?  Thoughts?  Could get odd when the focal point occurs within this new lens element, but maybe it is possible.  Also that whole "physics," "science," and "reality" may be issues as the same element would need to work with light coming in at different angles.  I do like how the listed focal lengths on the lenses would still be the equivalent focal lengths, even though they would technically be a little different, FOV would be the same.  This only happens if you have a 44 mm flange distance either natively or with an adapter or if we are bending light with a lens element and a shorter flange distance, as suggested.
« Last Edit: July 12, 2018, 12:04:25 PM by docsmith »

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Re: EF-X Mirrorless concept
« Reply #99 on: July 12, 2018, 11:25:43 AM »