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    EOS-R with EF lenses question

    Have been wanting to upgrade to full frame Canon for some time from my 70D, and saw the EOS-R as a way to do this and use my EF and even EFS lenses (at least for now).

    However I was surprised that the EOS-R with EF zoom lens at 300mm gives me a wider field of view than my 70D with EFS lens at 250mm. Is this me being real dumb about the effect of moving to a full frame sensor, or is it maybe something to do with the lens to sensor distance being compromised by the EF lens adaptor?

    Problem is I like wildlife photography and really need more zoom, not less. I haven't seen any info on high focal length zoom lenses coming for the EOS-R (RF lenses).

    Attached photos are 70D/EFS lens at 250mm followed by EOS-R/EF lens at 300mm. I exported them to JPEG and shrunk them by a factor of 10, so the EOS-R image is larger due to the higher pixel count. If I make them the same size then the difference in field if view is even more apparent, and if I had taken them both at 250mm then even more so.

    Steve

    LensTest250mm.JPGLensTest300mm.JPG

    #2
    Re: EOS-R with EF lenses question

    Yes...250mm with 1.6 crop factor gives 400mm ‘effective’ so quite a bit longer than 300mm on full frame.
    Brian Vickers LRPS

    brianvickersphotography.com

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      #3
      Re: EOS-R with EF lenses question

      I could understand the crop factor coming in if I used the EF lens on to 70D - in fact I have used the EF on the 70D to get shots of the moon - but surely when you use an EFS lense on the 70D then it is matched to the smaller sensor and you expect the 'effective' focal length to be what it says on the label - i.e. 250mm.

      Maybe I can set up a test to photograph something of known size and distance and calculate the effective focal length.

      Steve

      Comment


        #4
        Re: EOS-R with EF lenses question

        No, the actual focal length of an EF-S lens is given i.e. 250 mm, not the equivalent focal length compared to full frame. It is not "matched" to the sensor size. So the "crop factor" is the same with EF or EF-S lenses.
        EOS 6D, 6D Mk II, 80D, 70D, 100D, 200D, M50, M100. Canon 10-18, 18 - 55, 55 - 250 IS STM lenses, Canon 16 - 35 mm F4L, 35 mm EF-S macro, 50 mm F1.8 STM, 60 mm EF-S macro, MPE-65 macro, 85 mm F1.8, 200 mm F2.8 L II, M 15 - 45 mm, M 22mm F2, M 32mm F1.4. Sigma 24 - 35 F2 Art, 135 mm F1.8 Art, 17 - 50 F2.8 DC, 105 mm OS macro, 100 - 400 C, 150 - 600 C.

        Comment


          #5
          Re: EOS-R with EF lenses question

          OK - thanks for the explanation. I can see I need to do some homework on that front (its probably covered in an old copy of EOS magazine sometime). However, it sounds like I need a 100-400mmm to use the EOS-R for the same job that I use the 70D for (currently with 55-250 EFS lens), so I am glad I asked as I was going to go after a newer 70-300 (as mine is the old kit lens). If I get a 100-400 I can also use it on the 70D as a 160-640mm. If I wait for an RF lens I suspect the size and cost will be a bit high, and the ability to swap it onto the 70D will also go.

          Comment


            #6
            Re: EOS-R with EF lenses question

            One of the unfortunate things you notice about going full frame is that you have to spend more on lenses to match.
            I have the Sigma 100 - 400, it's a lot cheaper than the Canon and as good optically, apparently the autofocus is a bit slower, but I've not noticed any issues. All recent Sigma lenses have been tested with the adapter for the EOS-R and work correctly. It's worth considering. However, personally I tend to use it more often on my 80d, that extra "reach" is always tempting.
            EOS 6D, 6D Mk II, 80D, 70D, 100D, 200D, M50, M100. Canon 10-18, 18 - 55, 55 - 250 IS STM lenses, Canon 16 - 35 mm F4L, 35 mm EF-S macro, 50 mm F1.8 STM, 60 mm EF-S macro, MPE-65 macro, 85 mm F1.8, 200 mm F2.8 L II, M 15 - 45 mm, M 22mm F2, M 32mm F1.4. Sigma 24 - 35 F2 Art, 135 mm F1.8 Art, 17 - 50 F2.8 DC, 105 mm OS macro, 100 - 400 C, 150 - 600 C.

            Comment


              #7
              Re: EOS-R with EF lenses question

              If you look at the January-March 2014 issue, there is an article about EF-S lenses and sensor sizes. The focal length of a lens cannot change. However, the EF-S lens has a narrower field of view to an EF lens of the same focal length. For a cropped frame camera this is fine as the sensor cannot make use of the whole image that an EF lens can produce. So a 250mm lens can never be a 400mm lens, its just a comparison that sometimes is used misleadingly.
              Using Tapatalk

              Comment


                #8
                Re: EOS-R with EF lenses question

                It's important to note that as EF-S lenses are only designed to cover the APS-C size sensor, not full frame, when you use them on the EOS-R with the adapter the camera will automatically produce cropped 11.6-megapixel images that match the smaller image circle of EF-S optics. So you don't really get the benefit of full frame.
                EOS 6D, 6D Mk II, 80D, 70D, 100D, 200D, M50, M100. Canon 10-18, 18 - 55, 55 - 250 IS STM lenses, Canon 16 - 35 mm F4L, 35 mm EF-S macro, 50 mm F1.8 STM, 60 mm EF-S macro, MPE-65 macro, 85 mm F1.8, 200 mm F2.8 L II, M 15 - 45 mm, M 22mm F2, M 32mm F1.4. Sigma 24 - 35 F2 Art, 135 mm F1.8 Art, 17 - 50 F2.8 DC, 105 mm OS macro, 100 - 400 C, 150 - 600 C.

                Comment


                  #9
                  Re: EOS-R with EF lenses question

                  Originally posted by Richard W View Post
                  One of the unfortunate things you notice about going full frame is that you have to spend more on lenses to match.
                  I have the Sigma 100 - 400, it's a lot cheaper than the Canon and as good optically, apparently the autofocus is a bit slower, but I've not noticed any issues. All recent Sigma lenses have been tested with the adapter for the EOS-R and work correctly. It's worth considering. However, personally I tend to use it more often on my 80d, that extra "reach" is always tempting.
                  Yes, the extra reach certainly is tempting, and I have no plans on getting rid of the 70D - the in built flash is also dead handy. I have been told I should consider Sigma and Tamron, and have seen some great shots from Sigma lenses, but I am not familiar with their range and capability (like image stabilisation). Autofocus is a concern, but EOS-R should be better than 70D as it uses the dual plane sensor in some magical way, and is reputed to work at lower light levels.

                  I will have a look at the Sigma 100-400, that sounds promising.

                  Steve

                  Comment


                    #10
                    Re: EOS-R with EF lenses question

                    Originally posted by Richard W View Post
                    It's important to note that as EF-S lenses are only designed to cover the APS-C size sensor, not full frame, when you use them on the EOS-R with the adapter the camera will automatically produce cropped 11.6-megapixel images that match the smaller image circle of EF-S optics. So you don't really get the benefit of full frame.
                    https://www.canon.co.uk/mount-adapters-ef-eos-r/
                    Yes, I kind of guessed that would be the case before I bought it. I haven't bothered putting the EFS lenses on the EOS-R, even though they are compatible. When you have paid serious money for a 30Mp full frame sensor, seems odd to use it as a 10Mp APS-C (especially when I have a 20Mp APS-C sitting in the 70D).

                    Steve

                    Comment


                      #11
                      Re: EOS-R with EF lenses question

                      Originally posted by BobSapey View Post
                      If you look at the January-March 2014 issue, there is an article about EF-S lenses and sensor sizes. The focal length of a lens cannot change. However, the EF-S lens has a narrower field of view to an EF lens of the same focal length. For a cropped frame camera this is fine as the sensor cannot make use of the whole image that an EF lens can produce. So a 250mm lens can never be a 400mm lens, its just a comparison that sometimes is used misleadingly.
                      Thanks for that - I have dug that one out from my collection. Something to study this evening.

                      Steve

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