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EOS R, EF-S Lens Crop Loss of Megapixels

mindawoo
Apprentice

I currently using a t2i Canon 18 mp crop sensor camera, According to Canon, when EF-S lenses are used on the EOS R camera the camera "will automatically produce cropped 11.6-megapixel images that match the smaller image circle of EF-S optics." So a 30mp camera effectively is now 11.6mp, much less than what I have with my current set up. I am looking to move to full frame so the EOS R seemed to be the way to go until I hit this stumbling block. I can't afford to buy both the camera and new lenses at the same time but plan to upgrade lenses slowly as budget permits. Is this something I should be concerned about or will having a better sensor and newer technologies make up for the loss in megapixels?

31 REPLIES 31


@hearkg wrote:

Please create a firmware upgrade to allow us to use the whole sensor with ef-s lenses if any of the people at Canon Read this.

I know that the image circle of an ef-s lens can't cover the whole sensor. But wider lenses are capable of producing very good macro images when mounted backwords. I have a 100mm macro lens but I really want to use my old 18-55mm kit lens as a great macro lens because it produces larger magnification than the 1:1 100mm macro lens.
please allow us to use the whole sensor with ef-s lenses. 🙏🥺🙏🥺🙏

Make the firmware to change the mode to 1.6x crop whenever an ef-s lens is attached to the camera but let us change it back to full sensor mode in the menu, so the people who know about this will change intentionally and no one will complain about the huge vignette when mounted in the foward direction.
Please.......


I'm sorry, but your issue does not make any sense.  When you reverse a lens there no longer any electronic connections being made between lens and camera.  So, why would the camera body think you are using a EF-S lens, or any lens for that matter?  

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"The right mouse button is your friend."

Thanks for the reply,

I think you havn't heard of "meike mk-c-up reverse mount adapter".
have a look at it.
20200420_114222_HDR.jpg

 

so, here I'm holding a full frame super macro lens that can autofocus with aperture controll and Image stabilization.
this works perfectly with DSLRs.
the only problem is the 1.6x crop enforcement in EOS-R.

I have heard of that adapter.  You could have mentioned it from the start.

 

[EDIT] It is a littlle bit of a surprise to learn that the adapter transmits the lens type to the camera.  That's a pretty neat trick because I always thought that this was done mechanically.

 

I have a cheap 1.4x telecom, which I can use to attach an EF-S lens a full frame body.  Of course, I see the full image circle.  My point is that the lens mount info is not transmitted to the camera body, even though I have full electronic control of the lens.

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"The right mouse button is your friend."

Anyways, the important thing is to let Canon know that we need a firmware update to overcome this issue.


@hearkg wrote:

Anyways, the important thing is to let Canon know that we need a firmware update to overcome this issue.


Ain't gonna happen.

Will you volunteer to man the phone lines to handle all the calls canon will get complaining that the edges of the image are poor quality when using EF-S lenses?

"Anyways, the important thing is to let Canon know that we need a firmware update to overcome this issue."

 

Canon is never, reasonably so, and will never make a FW to make sure third party accessories work on their cameras. As a matter of fact Canon will discourage their use.

EB
EOS 1DX and 1D Mk IV and less lenses then before!

@ That`s a fact 👍😂

Hi, @

it might not happen if they do it like this
Capture.JPG

yes actually a teleconverter may have a circuit inside it because the displayed aperture values in camera needs to be changed when the lens is mounted with a teleconverter and as a result the camera will not directly communicate with the lenses.

These extension tubes and reverse mount adapters don't have any electronic circuits inside them, they are having just a bunch of wires connecting the lens to the camera body. so, the camera can directly communicate with the lens.

🙂


@hearkg wrote:

yes actually a teleconverter may have a circuit inside it because the displayed aperture values in camera needs to be changed when the lens is mounted with a teleconverter and as a result the camera will not directly communicate with the lenses.

These extension tubes and reverse mount adapters don't have any electronic circuits inside them, they are having just a bunch of wires connecting the lens to the camera body. so, the camera can directly communicate with the lens.

🙂


Aperture values have nothing, repeat nothing, to do with the type of lens mount.  Let me repeat that again.  Transmitting aperture control data has NOTHING to do with the type of lens mount.  Nothing.

 

You are probable correct, when you say that these Meike reverse mount adapters do not have any electronic circuits inside of them.  They do not cost enough to have any internal smarts.  You should probably use a full frame lens, instead of an APS-C lens.  I'd bet that the EF 50mm f/1.8 STM could do a pretty good job of it.

 

BTW, seeing how this item is no longer in production with Meike, I think your suggestion for a firmware update is not only wishful thinking, but it has become entirely moot.

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"The right mouse button is your friend."
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