07-10-2025 11:06 AM
Hi! I am a beginner photographer. I have an old Canon Xsi I have been using and am planning to upgrade to R6 MII. I am interested in nature, wildlife and macro photography. I was planning on investing in the RF 100mm F2.8 L Macro IS USM lens for macro. I was wondering if I could use my current lenses with the Canon Control Ring Mount Adapter EF-EOS R:
* EF-S 18-55mm 1:3.5-5.6 IS
* EF 70-300mm 1:4-5.6 IS USM
When checking with a camera shop, I was told not to bother with the adapter for these "cheap" lenses. Does the mount adapter work well with the lenses I listed or would it be better to go ahead with RF lenses instead? Do you have recommendations for an "everyday" RF lens for nature/wildlife shooting?
I appreciate any assistance the community can provide.
Thanks!
Solved! Go to Solution.
07-10-2025 11:33 AM - edited 07-10-2025 11:36 AM
EF-S lenses are not worth your time adapting to a Full Frame camera since there will be a great reduction in megapixels. In Full Frame mode the camera can utilize all 24.2 megapixels available. In APS-C Mode you’re limited to 9.5 megapixels because the lens cannot project an image circle large enough to cover the entire image sensor. Your current Rebel has a 12 megapixel image sensor. What is your budget for a camera and a lens since you asked about both. The 70-300mm even though it’s Full Frame it uses a cheaper and slower form of USM. This form of USM is called Micro USM. It’s very slow just like Micro Motor which is found in older lenses. Sure the lenses can work when adapted. But you’ll be very restricted by lens and the camera will take a performance hit. A lot of features will be unavailable or function in a degraded manner. Not to mention these AF motors have been retired by Canon for a reason. They’re just too slow for modern cameras. There isn’t a lens that can do it all in one package.
07-10-2025 11:59 AM - edited 07-10-2025 12:10 PM
Hey Ljohns, welcome to the community. The R6 MkII is a nice choice making the transition to a MILC. Congrats on the new body.
The EF-S 18-55mm 1:3.5-5.6 IS can be used with an adapter but the R6 will be placed into crop mode and (1.6x) and leave you with about 9.5 MP to use on your 24 MP sensor. Personally I would not bother with this lens, it is supposed to be used on a crop sensor camera and will not allow you to take full advantage of the R6 sensor.
There are a three versions of the EF 70-300mm 1:4-5.6 IS USM which will work with the Canon EF - RF adapter but you will not be able to take advantage of all the functionality of the R6 MkII. You may want to go to a local Canon dealer and test it once you receive you body, Also, EF lenses are moving to end of life and and getting them serviced will be a challenge at some point in the future.
On both of these lenses I would agree with sales person at the shop and not use those lenses moving to mirror-less. Use them for trade if you have the ability to pick up RF glass.
Since you don't mention a budget and are focusing on Nature/Wildlife you may want to take a look at these lenses. I'm not sure what you mean by nature but these suggestions would be good for wildlife.
I added the RF100-400mm F5.6-8 IS USM because I personally use it for wildlife, it is the bare minimum for most wildlife. You also have to keep in mind it has limitations. At 400mm you will need to be closer to your subject to fill the frame as the 24 MP sensor does not give you as much to work with when you crop. If the images are going to be used on line you will be fine but if you are going to print it will matter.
On a budget the RF200-800mm F6.3-9 IS USM is a good lens for wildlife, it gives you nice reach and the IQ is pretty good for a lens at this price point.
The RF100-500mm F4.5-7.1 L IS USM is a stud but you are going to pay a higher price for an L series lens.
Also, be aware that none of these lenses are super fast and need light. On the positive side your R6 MkII manages low light extremely well so the lenses mentioned will be a good balance but in low light you may have to bump the ISO and remove some noise in post production.
If you are in the States keep an eye on the Canon Refurbished Marketplace, they have some nice deals on R glass and carry a one year limited warranty
R3 ~ R5 ~ R6 Mk II ~ R50
Lenses: RF Trinity and others
Adobe and Topaz Suite for post processing
Personal Gallery
07-10-2025 11:33 AM - edited 07-10-2025 11:36 AM
EF-S lenses are not worth your time adapting to a Full Frame camera since there will be a great reduction in megapixels. In Full Frame mode the camera can utilize all 24.2 megapixels available. In APS-C Mode you’re limited to 9.5 megapixels because the lens cannot project an image circle large enough to cover the entire image sensor. Your current Rebel has a 12 megapixel image sensor. What is your budget for a camera and a lens since you asked about both. The 70-300mm even though it’s Full Frame it uses a cheaper and slower form of USM. This form of USM is called Micro USM. It’s very slow just like Micro Motor which is found in older lenses. Sure the lenses can work when adapted. But you’ll be very restricted by lens and the camera will take a performance hit. A lot of features will be unavailable or function in a degraded manner. Not to mention these AF motors have been retired by Canon for a reason. They’re just too slow for modern cameras. There isn’t a lens that can do it all in one package.
07-10-2025 11:59 AM - edited 07-10-2025 12:10 PM
Hey Ljohns, welcome to the community. The R6 MkII is a nice choice making the transition to a MILC. Congrats on the new body.
The EF-S 18-55mm 1:3.5-5.6 IS can be used with an adapter but the R6 will be placed into crop mode and (1.6x) and leave you with about 9.5 MP to use on your 24 MP sensor. Personally I would not bother with this lens, it is supposed to be used on a crop sensor camera and will not allow you to take full advantage of the R6 sensor.
There are a three versions of the EF 70-300mm 1:4-5.6 IS USM which will work with the Canon EF - RF adapter but you will not be able to take advantage of all the functionality of the R6 MkII. You may want to go to a local Canon dealer and test it once you receive you body, Also, EF lenses are moving to end of life and and getting them serviced will be a challenge at some point in the future.
On both of these lenses I would agree with sales person at the shop and not use those lenses moving to mirror-less. Use them for trade if you have the ability to pick up RF glass.
Since you don't mention a budget and are focusing on Nature/Wildlife you may want to take a look at these lenses. I'm not sure what you mean by nature but these suggestions would be good for wildlife.
I added the RF100-400mm F5.6-8 IS USM because I personally use it for wildlife, it is the bare minimum for most wildlife. You also have to keep in mind it has limitations. At 400mm you will need to be closer to your subject to fill the frame as the 24 MP sensor does not give you as much to work with when you crop. If the images are going to be used on line you will be fine but if you are going to print it will matter.
On a budget the RF200-800mm F6.3-9 IS USM is a good lens for wildlife, it gives you nice reach and the IQ is pretty good for a lens at this price point.
The RF100-500mm F4.5-7.1 L IS USM is a stud but you are going to pay a higher price for an L series lens.
Also, be aware that none of these lenses are super fast and need light. On the positive side your R6 MkII manages low light extremely well so the lenses mentioned will be a good balance but in low light you may have to bump the ISO and remove some noise in post production.
If you are in the States keep an eye on the Canon Refurbished Marketplace, they have some nice deals on R glass and carry a one year limited warranty
R3 ~ R5 ~ R6 Mk II ~ R50
Lenses: RF Trinity and others
Adobe and Topaz Suite for post processing
Personal Gallery
07-10-2025 01:12 PM
Thanks so much for the quick response. The information you provided was very helpful in understanding why the camera shop didn't recommend using an adapter. I will look for an RF lens instead.
Thanks again for your help!
07-10-2025 01:13 PM
Thank you for the information you provided it was very helpful. I will definitely take a look at the lenses you recommended.
Thanks again!
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