Hi, this adapter is for Canon EOS mount lens to Sony E NEX mount camera, we checked the sony a 7iii camera mount is E mount , this adapter can fit it , but you can reconfirme it , thanks.  

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. 

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. Adapting APS-frame lens to full-frame camera, it may generate vignetting, some cameras could correct it by adjust APSC, please contact us and provide your lens&camera model to check the way to correct it.
2. Adapting full-frame lens to APS-frame camera (i.e: large format to medium format, medium format to 35mm, 35mm to micro 4/3) provides excellent edge-to-edge sharpness. The smaller image field helps minimize the effects of lens distortion and aberration by using the 'sweet spot' or center of the larger lens image circle. and it will magnify the focal length by 1.6 on Canon, 1.5 on Nikon and Sony，2.0 on M4/3 camera.