EF EOS R Adapter

Just got an adapter. Have not yet bought the camera Soon. But a couple fo questions:

1. The instructions say:

Since a lens’ minimum focusing distance is lengthened when this adapter is
attached, maximum magnification and field of view might change.

This surprises me. Does the minimum focusing distance really change with EF lenses and this adapter? How much?

2. The instructions also say to attach the lens to the adapter, then attach to the body. To remove, remove BOTH the lens and adapter then separate the lens from the adapter.

This seems really odd to me. I expected to keep the adapter attached to the body at virtually all times and change lenses as needed. Having these extra steps will get in the way of a normal lens change.

What are you folks doing? What do you think?

When I am switching between my EF lenses I leave the adapter on the camera. I guess I do not read instructions very well

Unless a real good reason is identified here I will probably continue leaving the adapter on the camera while changing EF lenses. As long as the camera is off I can't see any reason it would matter.

Got to agree.

I emailed Canon CPS last night with these questions. Will post when the reply today. If I have to remove the adapter each lens change, that's a game changer and a waste of time. And my third hand is on backorder

I don't change my lenses when the camera remains turned on, but someone may care to see if there is difference in the on position regarding whether or not the camera closes to shut out dust.

When power is turned off, the camera closes regardless.

rebop wrote in post #18846229
Just got an adapter. Have not yet bought the camera Soon. But a couple fo questions:

I thought the EF-EOS-R Adaptor was supplied with the camera.

SOME dealers have had specials that include the adapter. Some countries include it. It is not included in the US.

Canon CPS replied and I strongly disagree with their answers and have replied that way:

The instructions also say to attach the lens to the adapter, then attach to the body. To remove, remove BOTH the lens and adapter then separate the lens from the adapter.

Canon: Same as if you were to use an extender with a lens, it's recommended to attach the lens to the adapter first and then to the camera. This will prevent mis-communication to the camera from occurring.

Me: The instructions also say (and I agree) that the EOS R should always be turned off for a lens change. That being the case, what possible miscommunication could occur? This does not make sense. And yet it is specific in the instructions.

Since a lens’ minimum focusing distance is lengthened when this adapter is attached, maximum magnification and field of view might change.

Canon: The closest focusing distance is referring to the use of the RF lenses to the EF as a comparison. For example the RF 50 f/1.2L USM has a closest focusing distance of 1.3 ft. While the EF 50 f/1.2L USM has a closest focusing distance of 1.48 ft. The design of RF lenses will always allow the closest focusing distance be shorter since the design of the lens allows it to be closer to the sensor. If you were to take and image with EF 50 f/1.2L USM on a EOS 6D and then take the same image with the EF 50 f/1.2L USM on the EOS R the image would be the same.

Me: I disagree with your interpretation. This is NOT comparing RF lenses to the EF EOS R adapter. It says:

Since a lens’ minimum focusing distance is lengthened when this adapter is attached, maximum magnification and field of view might change.

So this is for an EF lens using the adapter. I need to know how this changes focus distances for ALL my 7 EF L lenses.

Can you please provide more accurate information?

Not happy with both their answers.

Comunication occurrs when camera is off. It's easy to see, remove or attach a lens with the camera off and watch the little red LED flash.
I ignore Canons recommendations and do what is more convenient. That means EF adapter stays on my R body and extender stays on DSLR if it's easier.
I doubt the claims of adapter affecting MFD. The adapter places the lens the same distance from the sensor as it would be on a DSLR.

I agree with you on both Dave. Unfortunately I am cursed with a rare disease that causes me to read owner's manuals. These did not ring true. Nor did Canon's answers.

Updated as I learn more.

It is included in the US. Well the one from Adorama come as a free gift,And Canon and BH offer it also as a gift at this time.

I have not had a problem mounting or removing any EF lens while the adapter is on the body. I simply turn off the camera before removing the lens.

Latest dialog with Canon CPS:

Canon: Some of instructions are specific to avoid potential complications, but sometimes they are just practical suggestions. With the camera off, it doesn't really matter how you attach the lens and extender. Attaching the lens onto the extender first can ensure that the two are securely attached though. Similarly, storing the extender on the camera with the cap on it should not cause any issues. Just be sure to attach the lens when the camera is off. That decreases the chance that dust will be drawn into the camera.

ME: This should be the same with an RF lens. Having the adapter attached should not change the probability of drawing dust into the camera. The key on mirrorless seems to be having the camera off. This is why it seems so confusing for Canon (you) to publish a specific order for connecting and disconnecting. That being said, those that own the camera seem to have no issue doing it the "logicial" way of keeping the adapter on the camera while changing out EF lenses.

Canon: We don't have published specs for how the minimum focus distance might change with the adapter, but the changes, if any, should be marginal, but you are welcome to do your own tests to see what kind of results you can get.

ME: Now, if you are going to print that the field of view and minimum focus distance will change with an EF lens and an adapter (this is not PERFECTLY clear in the instructions, but appears to be just that), then I think it is the responsibility of Canon and its engineers to provide that information, not me. Even if just a handful of the most common EF L lenses so one can extrapolate from there. For example, on my 70-200 2.8 L I need to always be conscious of being more than 4" from my subject (3.94') as I tend to try to be closer at times. If this is going to change, I would like to know. I don't think I should be the one to test. Disagree?

As you can see, this even confused XXXXXX into thinking it is a comparison between RF and EF lenses with the adapter, which it clearly is not.

I have a discussion on these two topics going online. I will ask if anyone has experienced a change in MFD, FOV and magnification using a lens with this adapter or on a DSLR body.

Particularly with larger lenses, it's much easier to attach camera to lens with the extender already on the body rather than extender attached to lens.
So much easier to line up the extender to the lens compared to aligning body with rear of lens or extender.

Choderboy wrote in post #18847066
Particularly with larger lenses, it's much easier to attach camera to lens with the extender already on the body rather than extender attached to lens.
So much easier to line up the extender to the lens compared to aligning body with rear of lens or extender.

I tried changing EF lenses on my EOS R in the on position, with and without the adapter mounted. No real change about dust. It stays open unless the power button is turned off.

Then it came to mind whether the diameter of the EF lenses is ever so much smaller that if angled, may insert into the hole and damage the sensor ?? Not something I want to test, but a question I wondered about.

???

mdvaden wrote in post #18847292
I tried changing EF lenses on my EOS R in the on position, with and without the adapter mounted. No real change about dust. It stays open unless the power button is turned off.

Then it came to mind whether the diameter of the EF lenses is ever so much smaller that if angled, may insert into the hole and damage the sensor ?? Not something I want to test, but a question I wondered about.

???

The mounts have the same 54mm internal dimensions.
Distance from flange to sensor is 20mm for the RF.
So you would need a lens with 20mm or more of something protruding from the rear of the lens to cause a problem, if you could mount the EF lens to the R body.
However you cannot mount an EF lens to R body. The R bayonet mount tabs prevent an EF lens being mounted.

Therefore using R adapter is the only way you can mount EF to R and that means flange to sensor is back to the 44mm of a DSLR.