Canon EOS Elan II not working with Samyang 85mm 1.4

[Geanbean]

Hey all, look for some help with my Elan II film camera not working with my Samyang EF lens. The weird part is it worked for literally a minute when I got it, but now autofocus and manual focus do not respond. But my Canon nifty fifty works just fine. I know also it that it shouldn’t be because it’s a Samyang lens, cause my film Canon Eos Rebel Ti works just fine with the lens. But now that cameras battery dies within 10 minutes which is a whole other problem. Does any one know which Canon film camera 100% work with newer EF lenses?

[deebatman316]

Your Samyang lens IS NOT compatible with your camera. Also NOT all EOS 35mm film or EOS Digital cameras work with all 3rd party lenses. Your Canon nifty fifty works on all EOS 35mm Film and EOS DSLR cameras. Also the Rebel TI is newer than the Elan II. 

[Geanbean]

Thank you, I wasn’t sure if was going crazy or not. Is this incompatibility stated by Canon anywhere? Also, so would you say my best best is to make sure I’m using the Samyang with the last released SLR film cameras from Canon?

One last question! Do you think using the Samyang on the Rebel TI could have altered its battery life? Once I put it on I'm having serious battery issues or is that just coincidence in your opinion?

[deebatman316]

1. Samyang claims compatibility with the Canon EF Mount. Canon never said that Samyang or any other 3rd Party lenses were compatible with its mount. Canon knows its communication protocol they don't license it out. Samyang had to reverse engineer it to make there lens work on the EF Mount. 
2. Yes I've seen 3rd party lenses drain camera batteries. Once the 3rd Party lens is removed the problem goes away. Canon's lenses don't cause these problems that you describe. 
3. You're camera requires Full Frame EF lenses. 1st Party Canon EF-S won't mount on your camera. The lens is designed NOT to mount to EOS 35mm Film SLRs, Full Frame Digital cameras & APS-H (1.3x) Digital cameras. EF-S lenses are designed protrude into the camera body. If they could be mounted to a Full Frame camera the mirror would collide with the back of the lens causing serious damage to the camera. EF-S is a separate Crop sensor camera ONLY Mount. It is mechanically different from the EF Mount but electrically the same. All APS-C cameras work with Full Frame EF lenses. Older EOS AF SLRs work with ALL EF lenses regardless of age new or old. Just Not EF-S lenses which are mechanically incompatible.
4. Make sure you get Full Frame lenses for your camera. 3rd Party APS-C lenses use the Full Frame EF Mount but provide an APS-C image circle. You'll see vignetting (black areas in all 4 corners).
5. Canon's last released EOS AF SLRs may or may not be compatible with newer 3rd Party lenses. But all of Canon's EF lenses work. EF-S, EF-M, RF & RF-S lenses won't mount.