This adapter ring Nikon-EOS is for Nikon F mount to Canon EOS camera, you mentioned your lens mount is F mount, so this item is useful for you. 

hello ， the AI to EOS adapter ring i ssuitable for nikkon AI Mount lens and canon camera body. so you need to confirm your sigma lens specific mount . We care about our customers, any questions, you can ask us directly at customer@kentfaith.com. All emails would be replied in 24 hours, no exception. 

hello， The Nikon-EOS adapter ring fit for nikon AI mount lens and canon EF camera. so the adapter ring fit for your Nikkor 55mm 3.5 ain’t lens on to canon 80d 

FD-EOS fit for Canon FD mount lens and canon EF mount camera body. canon 60d is EF mount, so the adapter ring can work with your camera, but you need to check your lens mount. could you pls let us know your lens specific model? service(AT)kentfaith(DO NOT)com, Please note: It is not same between Canon FD mount and EF mount, this adapter ring is only for Canon FD mount lens, please contact us if you want to purchase for Canon EF mount lens. 

1. As Canon’s EOS lenses are electronically controlled，most Canon EF mount lenses do not feature a manual aperture ring，so when used on our EOS-M4/3, which is a full manual operation adapter ring, the aperture could not be transferred to the camera, it will stop down to its smallest f/stop by default.
2. Some buyer mentioned could not adjust the aperture, actually this is because your lens does not have the aperture control function, If your lens does not have a manual aperture control ring, it will stop down to its smallest f/stop by default
3. You could set your aperture via this way, but we do not suggest to use this way: You can control the f-stop by putting the lens on an EOS body, stop it down using the DOF preview button, and while holding the button down taking the lens off the camera. You can then transfer the lens to the M4/3 camera, and it will retain the f-stop.