EF 24-105mm f/3.5-5.6 IS STM Won't Focus on EOS Film Camera

[Filmfan]

Hello, I have a film camera: Canon EOS Rebel Gii and I recently bought a Canon EF 24-105mm f/3.5-5.6 IS STM lens to go with it. I did a lot of research about which lenses are compatible, and all stated that EF lenses would work. However, the lens won't focus manually or automatically unless I first connect the original lens it came with, autofocus it, take it off, then put the Canon EF 24-105mm f/3.5-5.6 IS STM lens on. If I turn the camera off, then I have to go through the whole process again and it is quite a cumbersome. Plus I don't want to carry around my old lens everywhere just for this purpose. I was wondering if anyone has run into this issue before? Is it because it's a STM model? 

[Tronhard]

Hi and welcome to the forum:

Well, the camera is supposed to take EF mount lenses, and the fact that it is an STM lens should not, in itself, cause the camera to not focus.   Do you have access to another EOS camera (of any type) that can take an EF or EF-S lens so you can test your 24-105 on that?   Did you purchase the lens new, or second hand?  Where did you get the lens from?

[jrhoffman75]

As Trevor says, you need to verify that the lens functions properly on a different camera. 

[Filmfan]

Yes I verified that it works on another camera just fine!

[jrhoffman75]

---

@Filmfan wrote:

Yes I verified that it works on another camera just fine!

---

Is that other camera a film camera?

Try wiping all the contacts in the mirror box with a clean microfiber cloth (don't use a pencil eraser like you see some folks recommending). Wrap a pencil (or some other similar object) with a microfiber cloth and depress each one of the contacts to be sure none of them are sticking.

Just so you know, STM lenses are focus by wire, so even if you are trying to manual focus you need to be pressing the shutter button to provide power to the lens.

[Filmfan]

I tried this and sadly it did not help 😔 

[shadowsports]

Thank you filmfan,

Then our next question would be in regards to your camera.  Do other lenses work with it?  Are you the original owner.  Was it purchased new, used, etc. ? 

[Filmfan]

I just bought another lens which comes next week so we will see if it works with that. I have a feeling it is the camera. I bought it used, so I'm not the original owner. 

[deebatman316]

Canon has had Focus by Wire lenses since the beginning of the EOS system. The first of such lenses was the EF 300mm F/2.8L USM lens. ALL of Canon's early Ring Type USM lenses are focus by wire. Canon had not released lenses with a clutch override system yet. Also make sure the camera is set to One Shot AF. The electronic focus ring does NOT work in AI Focus or AI Servo focus modes.

Edit: Your camera doesn't have those restrictions. It was the very first and early Rebel Film camera models. Your camera does NOT have this restriction. It should work like any other EOS Film Body or EOS DSLR cameras.

[Filmfan]

I tried focusing it with MF on and it didn't work. Is there another setting I should push as well?