https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/EOS-R100-cannot-work-with-tele-lens/m-p/539328#M130982 <P>Sounds like you bought a cheap, all-manual 800mm lens. Manual focus, aperture. No automation whatsoever. Using an adapter does not add to its function (or lack thereof).</P> <P>The camera also does not sense that a lens is present. You need to go into Menus and find the option to enable the shutter without a lens being attached.</P> <P>What did you expect from this lens?</P> Thu, 13 Mar 2025 02:50:09 GMT normadel 2025-03-13T02:50:09Z https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/EOS-R100-cannot-work-with-tele-lens/m-p/539323#M130981 <P>Hi everyone, I just buy a new r100 canon and was buying online lens tele 800mm with adapter , and when I trying to take a picture I just got this sign and cannot take a picture , please help me if someone was have the same problem before , thank you</P> Thu, 13 Mar 2025 12:07:50 GMT https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/EOS-R100-cannot-work-with-tele-lens/m-p/539323#M130981 regaa 2025-03-13T12:07:50Z https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/EOS-R100-cannot-work-with-tele-lens/m-p/539328#M130982 <P>Sounds like you bought a cheap, all-manual 800mm lens. Manual focus, aperture. No automation whatsoever. Using an adapter does not add to its function (or lack thereof).</P> <P>The camera also does not sense that a lens is present. You need to go into Menus and find the option to enable the shutter without a lens being attached.</P> <P>What did you expect from this lens?</P> Thu, 13 Mar 2025 02:50:09 GMT https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/EOS-R100-cannot-work-with-tele-lens/m-p/539328#M130982 normadel 2025-03-13T02:50:09Z