topic Re: R5/EF Adapter compatibility in EOS DSLR & Mirrorless Cameras

R5/EF Adapter compatibility

drodow — Sun, 12 Dec 2021 00:26:41 GMT

Hello, I have the EOS R5 with a Canon Mount EF Adapter and a 70-300mm 5.6L IS USM lens. I need to know it the Canon 1.4x extender will work with this configuration? I hope so otherwise I will have to sell the 300 and buy the 100-400.
Thank you for your help.

Re: R5/EF Adapter compatibility

kvbarkley — Sun, 12 Dec 2021 02:31:12 GMT

Are you talking an RF100-400? Whether the extender works or not, it is probably best to have an RF lens.

Re: R5/EF Adapter compatibility

drodow — Sun, 12 Dec 2021 02:44:47 GMT

I hadn't thought that far about it yet. I'd have to research the advantages as I really wanted the extender for bird photography, more is better. With the price of the extender plus the EF 100-400, I'm not that far away from the price of the RF 100-500. Thanks

Re: R5/EF Adapter compatibility

Tronhard — Sun, 12 Dec 2021 03:55:03 GMT

The EF 70-300L is NOT compatible with Canon's teleconverters - they will physically not fit on this lens.

If you want to get an extended reach, then the RF100-500L is a brilliant choice for the R5 (at a cost), but if you want to stick with EF lenses, then I can recommend the 100-400MkII or the Sigma 150-600c lenses.

However, given that the R5 has 45MP, it might be worth keeping your EF 70-300L and simply crop - it IS an excellent lens!

To demonstrate the potential of a higher MP sensor with this lens, this is the 70-300L with the quite unforgiving Canon EOS 5DsR, which has the cancelled AA filter and at 52MP shows any flaw in the lens or its use. Of course, to post here, the images have had to be SERIOUSLY downgraded, but you should get the idea.

As taken:

After cropping:

Re: R5/EF Adapter compatibility

FloridaDrafter — Sun, 12 Dec 2021 17:40:18 GMT

@drodow wrote:
"Hello, I have the EOS R5 with a Canon Mount EF Adapter and a 70-300mm 5.6L IS USM lens. I need to know it the Canon 1.4x extender will work with this configuration? I hope so otherwise I will have to sell the 300 and buy the 100-400.
Thank you for your help."

As mentioned, the extender won't physically fit the EF 70-300mm L f/4-5.6 IS USM II, so IMO if you are going to spring for the EF 100-400mm L f/4.5-5.6 IS USM II, I would go for the RF 100-500mm L f/4.5-7.1 IS USM. I agree with Trevor that the EF 70-300L II is a great lens. I have used it on all of my bodies, from an XSi, through various Rebels to the 7D mark II, 5D mark IV and now the R5 and R6. You will get good resolution with it on the R5 so you can crop in, if need be. I also have the EF 100-400mm L II and a 1.4X extender. I really don't care for that combo as it just doesn't give me the res I want, plus you are giving up a stop at 400mm. Like you, I shoot birds, more times than not, tiny birds like warblers. The EF 100-400mm L II and ring adapter on the R5 works great and if I get close, cropping still leaves plenty of detail and I could get a 10" print when needed.

Although I like the EF 100-400mm L II, I still bought the RF 100-500mm L for the R5 and let the EF 100-400mm L II live on the 5D IV. I like the RF glass and although I can only see a slight improvement in IQ in the RF L over the EF L glass I own, there is more to it then that, like they are generally lighter, designed better (according to specs), and I like the redesigned hood of the RF 100-500 L, I know, small thing, but it is what it is. Although EF glass works fine on the R systems, I think the RF glass is the way to go if you can afford it, it just feels right.

Tufted Titmouse - R5 and RF 100-500 L at 35 feet.

Ruby-crowned Kinglet - R5 and RF 100-500 L at 40 feet. These birds are under 3" and a pain to shoot. They hardly ever sit still and rarely come out in the open.

Newton

Re: R5/EF Adapter compatibility

AtticusLake — Sun, 12 Dec 2021 08:42:58 GMT

This is potentially misleading -- an RF lens will NOT work on an EF extender, just as you can't adapt an RF lens to an EF body.

There is an RF extender, and like the EF extender, it has a limited list of lenses it works with -- see the manual for the list. It's a VERY short list, and the 100-400 is NOT on the list; the 100-500 is. See the manual here:

https://www.canon.co.uk/support/consumer_products/products/cameras/rf-lenses/extender-rf-1.4x.html?type=manuals&language=

Of course a longer lens *instead* of a converter should be fine.

Re: R5/EF Adapter compatibility

jrhoffman75 — Sun, 12 Dec 2021 18:36:39 GMT

The issue with the 70-300 lens is that for lengths shorter than around 250mm the rear element of the lens extends beyond the mount and will hit the extender. If you are willing to accept essentially a fixed 420mm lens then it will work.

Re: R5/EF Adapter compatibility

Tronhard — Sun, 12 Dec 2021 19:33:43 GMT

John, I have the EF 70-300L lens and both of the Canon MkIII extenders and literally just tried to attach them to the EF70-300L. According to my experience in doing so, the rear element of the 70-300L has very little travel and the 1.4x MkIII extender cannot be attached at any focal length, while the 2.0x MkIII extender does but only very close to the 300mm FL, so your answer appears to be only partly correct. Furthermore, being a 2x unit, the lens loses 2 f-stops, rendering an effective f-stop of f/11.
However, I would not suggest using an extender at all as the very limited benefit of attaching an extender is arguably not worth the risk of damage to the rear element is IMHO. Canon have not recommended using any extenders with this unit.

If there is a 3rd party extender that does work, and you are basing your recommendation on this, it might be helpful to be specific.

Re: R5/EF Adapter compatibility

jrhoffman75 — Sun, 12 Dec 2021 19:08:18 GMT

This is what was reported in the-digital-picture.com

Then, in a major firmware updateannouncement for the Canon EOS-1D X, Canon included the 70-300 L and Canon EF 1.4x III Extender combo on a compatibility list.

Intrigued, I did more experimenting. What I learned is that the 70-300 L's rear element retracts into the lens far enough that, at about 250mm, there is enough clearance for Canon extenders to mount.

The available with-1.4x focal length range is about 350-420mm and 500-600mm with the 2x installed. Zooming out wider than the 250mm-or-so zoom ring mark results in a physical bump inside the lens. I'm guessing that it is the rubber around the edge of the extender element contacts the rear 70-300 L lens element or its barrel. I do not recommend mounting this combination due to potential damage to the lens.

I of course felt the need to try out these unsupported combinations. My solution to the damage risk issue was to Gaffer Tape the lens zoom ring to lock it at the 300mm mark while using extenders.

Perhaps it is sample variation.

Re: R5/EF Adapter compatibility

FloridaDrafter — Sun, 12 Dec 2021 19:08:36 GMT

@jrhoffman75 wrote:
"The issue with the 70-300 lens is that for lengths shorter than around 250mm the rear element of the lens extends beyond the mount and will hit the extender. If you are willing to accept essentially a fixed 420mm lens then it will work."

That's pretty cool, John! I never thought to extend the EF 70-300 to 300 to attach the EF 1.4x III. I didn't realize that the rear element moves during zoom.

Newton

Re: R5/EF Adapter compatibility

Tronhard — Sun, 12 Dec 2021 20:25:10 GMT

I would be surprised if unit variation would account for what I found to be a significant inability to connect my 1.4 unit to the back of the 70-300L. I could not get it to lock at all. Using things like gaffer tape sounds to me like a very dubious way to proceed. If one is going to invest in a lens of the quality of an L lens, it seems to me to be much safer to simply crop afterwards, or put the R5 into crop mode and it will render around 18MP with an image crop of 1.6 and no risk.

As to Canon's compatibility chart; HERE is a link to what appears to be the current list.

I have downloaded the official Canon 1.4 and 2.0 MkIII Extender user material which includes their list of compatible lenses HERE and the 70-300 is definitely NOT on the list. So, if by some means you can attach the extender, it is not recommended and, IMHO, highly risky.
The EF 70-300L does not appear on the chart.

Re: R5/EF Adapter compatibility

FloridaDrafter — Sun, 12 Dec 2021 19:34:06 GMT

@Tronhard wrote:
John, I have the EF 70-300L lens and both of the Canon MkIII extenders and literally just tried to attach them to the EF70-300L. According to my experience in doing so, the rear element of the 70-300L has very little travel and the 1.4x MkIII extender cannot be attached at any focal length, while the 2.0x MkIII extender does but only very close to the 300mm FL, so your answer appears to be only partly correct. Furthermore, being a 2x unit, the lens loses 2 f-stops, rendering an effective f-stop of f/11.
However, I would not suggest using an extender at all as the very limited benefit of attaching an extender is arguably not worth the risk of damage to the rear element is IMHO. Canon have not recommended using any extenders with this unit.
If there is a 3rd party extender that does work, and you are basing your recommendation on this, it might be helpful to be specific.

Trevor, after reading Johns post, I tried the EF 1.4X III on my EF 70-300mm L II and it fit after extending the barrel to 300mm. Just from observation, the rear element seems to move quite a bit on the 70-300 L II. Not sure I would use it like this, but on mine it fit and didn't feel forced nor did I feel or hear any disturbing noises when zooming what small amount is allowed with the extender attached.

Newton

Re: R5/EF Adapter compatibility

Tronhard — Sun, 12 Dec 2021 19:51:08 GMT

From what I can see Canon does not make an EF 70-300L MkII lens, they DO make the EF 70-300 IS USM MkII lens, while the OP referred to the L version. What colour is the lens you tried?

I have tried to fit the 1.4x MkIII Canon extender to the following lenses, just now:

EF 70-300 IS USM MkI the extender is too wide diameter to fit
EF 70-300 IS USM MkII The rear element is fixed and flush, and does not fit
EF 70-300 IS USM L Fits only the 2.0MkIII extender at 300mm
I cannot find any reference to a 70-300L MkII lens in any Canon lens lists. The only other lens in this range is the EF 70–300mm f/4.5–5.6 DO IS USM, which I do not have, but is a very rare beast.

Re: R5/EF Adapter compatibility

FloridaDrafter — Sun, 12 Dec 2021 19:49:07 GMT

@Tronhard wrote:
From what I can see Canon does not make an EF 70-300L MkII lens, they DO make the EF 70-300 IS USM MkII lens, while the OP referred to the L version. What colour is the lens you tried?

Ooops, you are correct, as usual. I was remembering back to the non L push/pull and it's replacement "mark II" and was thinking it was a push/pull L... My bad.

But, yes, I tested the 1.4X III on the 70-300 L.

Newton

Re: R5/EF Adapter compatibility

drodow — Sun, 12 Dec 2021 19:50:44 GMT

Thank you very much for the helpful comments and recommendation!

Re: R5/EF Adapter compatibility

drodow — Sun, 12 Dec 2021 19:51:32 GMT

Thank you for the help and especially the pics showing cropping advantage. Very helpful info!

Re: R5/EF Adapter compatibility

Tronhard — Sun, 12 Dec 2021 19:59:34 GMT

So, we have many points at which one can be confused!
Certainly, my experience indicates that the EF 70-300L does not accept an extender and I cannot find a listing of any suggestion from Canon that this is the case. Nor can I find any reference to any lenses apart from the four units I listed.
I agree it seems logical to me that adding the extender between the EF-RF adapter and the body is unlikely to be incompatible.

Re: R5/EF Adapter compatibility

Tronhard — Sun, 12 Dec 2021 20:32:33 GMT

So, just this is what I understand so far...
You and John seem to be able to get the 70-300L to be able to attach the EF 1.4x MkIII extender.
I have now repeated my experiment with that combination three times and under no circumstances does the 1.4x attach to the back - it's not even close... I can get the 2.0x MkIII unit to attach in much the way John suggests.
HERE I cannot find any current documentation from Canon that they recommend using any extender with the EF70-300L. THIS is the user guide with the official Canon compatibility list for both of the MkIII extender versions, and the 70-300L is not on the list.

I would certainly be interested to see a specific reference somewhere that they DO. Otherwise anything else, even if they are work-arounds is a risk of damaging the lens IMHO.

Re: R5/EF Adapter compatibility

FloridaDrafter — Mon, 13 Dec 2021 05:42:36 GMT

@Tronhard wrote:
"So, just this is what I understand so far...
You and John seem to be able to get the 70-300L to be able to attach the EF 1.4x MkIII extender.
I have now repeated my experiment with that combination three times and under no circumstances does the 1.4x attach to the back - it's not even close... I can get the 2.0x MkIII unit to attach in much the way John suggests.
HERE I cannot find any current documentation from Canon that they recommend using any extender with the EF70-300L. THIS is the user guide with the official Canon compatibility list for both of the MkIII extender versions, and the 70-300L is not on the list.
I would certainly be interested to see a specific reference somewhere that they DO. Otherwise anything else, even if they are work-arounds is a risk of damaging the lens IMHO."

I think John just stated that it was supposed to attach/work if you extended the barrel to 300mm and that it was limited to 270mm-300mm. I'm not sure where he got that info and I don't think he said he actually tried it. I will go back and reread and make corrections to this post if I'm wrong. At any rate, his statement made me want to examine it further, which I did. I'm silly like that 🙂

EDIT: I now see where john got his info and that he did try it.

I guess you could damage the lens or extender if you forgot you were limited to 270-300mm and tried to pull it back to aggressively to 70mm, but my thought is you are taking a zoom lens, which in my case is why I have the lens to begin with (it's a zoom), and basically turning it into a prime (of sorts) without the advantages of a prime. So, IMO, it's a waste. But from my experiments, the EF 70-300mm f/4-5.6L IS USM with the EF 1.4X III Extender works as a 420mm.

Now, I have no idea why you can't get it to attach and I can't, without a doubt, prove that it does on my end because the EXIF data in DPP 4 from the test shots I took shows just the EF 70-300 L with no mention of the EF 1.4 III extender, and just shows the focal length being 300mm instead of 420mm. Typically the EF 1.4X III shows up in the EXIF data.

This is the EF 70-300mmL, EF 1.4X III Extender, attached to the EOS R5 using the Canon EF-RF adapter.

Screen cap of shot in DPP 4. Image was taken with a 5D mark IV, EF 70-300mmL, using the EF 1.4X III extender at 420mm even though EXIF says 300mm. This is 1 of 2 just to show that it is actually zooming to 420mm.

Screen cap of shot in DPP 4. Image was taken with a 5D mark IV, EF 70-300mmL, without the EF 1.4X III extender from the same spot in the room just to show that the lens is reaching 420mm. This is 2 of 2.

Please note that I used screen captures because the new forum does not show EXIF data any more in my plugin, or I just haven't figured it out yet. What a shame.

Newton

Re: R5/EF Adapter compatibility

Tronhard — Mon, 13 Dec 2021 03:56:39 GMT

Hi Newton:

Thank you for your studied and well-documented answer. I have been more concerned about two things:

1. the complications of all the variations in 70-300 lenses (there are 4), plus the different versions of the extenders (2x types, 3 versions of each).

2. The (to me) clear statement by Canon that the 70-300L is not on their list of approved lenses compatible with extenders. So, while I am glad that putting the extender on the lens may work for you (again, it doesn't for me), I am very dubious about the risk of doing so. For example, the 70-300L extends to zoom in, so if it was accidentally bumped from the front end, it could retract and cause the extender to impact the rear element of the lens.
I challenge anyone to provide proof that this is accepted by Canon in their own documentation - I have already offered links to the contrary.

So, as I see it the risk is very much the individual's decision. Certainly, in the context of the original question, I think it would be very unwise to suggest an undocumented and unapproved means of adding an extender to a person seeking advice. I accept the fact that John sought to provide some context, but I am dubious of the validity of the sources he quotes to justify the measure - to me what the manufacturer recommends should be the bottom line.