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Question about Quantaray Lens on EOS 5D


I'm brand new to the Canon EOS 5d.   I just received a Quantaray lens for Canon AF 28-300mm  3.5-6.3 LDO.  It has the EF mount.  The lens does not work in auto, the focus motor runs but does not focus.  When I depress the shutter button it clicks but does not take a picture.  The lens seem to function normally in manual mode.  The camera works fine.  I read that all film EF lens after 1987 should work on DSLR's.  Just seeking  help or am I the victim of some 3rd party lens not compatible to Canon?



No, not all third-party lenses are compatible with Canon EF.

For example older Sigma lenses with EF mount may not have working aperture with newer Canon cameras. With Sigma there is a workaround at Github:

"Older Sigma lenses with Canon EF lens mounts do not work on newer Canon bodies, because Sigma incompletely reverse engineered the EF protocol and did not implement all required commands. This is a DIY fix using an ATtiny13 microcontroller to modify the protocol, making the lens compatible again."



Hi dajeau1978 just because a 3rd party lens says for "Canon EF Mount" doesn't mean it'll be compatible with all Canon bodies especially newer bodies. Canon introduced the EF Mount in 1987 making it the world's first all electronic lens mount. 


40D, 5D IV, EF 16-35mm F/2.8L III, EF 24-70mm F/2.8L II, EF 28-135mm F/3.5-5.6 IS USM, EF 50 F/1.8 STM

430EX III-RT & 600EX II-RT


Current Gear: EOS 5D Mark IV, EF Trinity, EF 50mm F/1.8 STM, EF 85mm F/1.8 USM, 470EX-AI & 600EX II-RT

Retired Gear: EOS 40D & Sigma 17-50mm F/2.8 EX DC OS HSM


Canon don't really have any support for third party lenses.  So, leaving the lens itself aside, if you want to check if the camera is working properly, I would recommend attaching a native Canon EF lens (not an EF-S lens, it won't fit) to the 5D and see if it performs.  If it works, the issue is with your Quantaray lens.

If you are new to the 5D, then I suggest doing some homework on the menus and operation. 
You can download the manuals and software for it from Canon at this link .
There is a comprehensive series of videos on this camera on You Tube:

I would strongly suggest watching the videos so you can get a good grounding.  The camera is old but a pro piece of kit, however much depends on how well you use it - just like any other tool.

cheers, TREVOR

Before you ask us, have you looked in the manual or on the Canon Support Site?
"All the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris


I am not aware of the QUANTARAY 28-300MM F/3.5-6.3 All in One Auto-Focus Lens not working on a Canon body but I can tell you succinctly it isn't a very good lens. Certainly not worthy to use on a 5D. There is another lens that is around the same price point and much better if you can find one the Sigma Zoom Wide Angle-Telephoto 28-300mm f/3.5-6.3 DG Macro IF on the used market. Still would not be my first choice of lens, however.

EOS 1DX and 1D Mk IV and several lenses!