EF adapter for FD-mount Sigma 100-200mm F/4.5

[Mousetracker]

Hello. My youngest has become quite an accomplished birdwatcher. I've been taking him to regional parks and it's amazing what species he's been able to identify and share on the two ornithology apps he has. I have a Sigma 100-200mm f/4.5 lens I used to use all the time with my Canon AE-1. I still have that camera but I now own a Canon EOS Rebel T3i. I'm wondering if there is an adapter ring I could get to make my lens compatible with my EOS? If someone knows of an adapter for sale on Amazon or eBay, could they share the link with me? I'd like to try the lens out on the EOS when we go birdwatching. Thanks very much for your time.

[deebatman316]

Its not worth adapting FD Mount lenses to the EF Mount. No automatic aperture control, no communication between the lens and camera body. Also The kit lens out resolves your Sigma lens. No to mention EF lenses are designed to sit further away from the image sensor than an FD lens would. So adapting an FD lens you would lose focus to infinity and the adapter would have to have glass in it. Basically the adapter is a 1.26x teleconverter and the glass in the adapter is very poor optically. So its not worth the time adapting when you can find a native EF Mount lens.