Viewfinder stays black after I take a photo; 5D mark 1 - canon lens ef 50mm 1:1.8 II

[KikiSpoon]

Hello! I'm using a Canon EF 50mm 1:1.8 2 that I bought used a little over a year ago for my 5D.

I noticed a couple months ago that after I took a picture (which turned out totally normal) my viewfinder would stay black while using this lens, like the shutter never opened back up. It would 'reset' itself after removing the lens from the body.

I also use a zoom EF 75-300mm and that lens still works perfectly fine. Any suggestions as to what the problem might be and how I might go about fixing it?

[kvbarkley]

Sounds like a sticky mirror, though I have no idea why the lens would matter except for slower shutter speeds on the longer lens.

[diverhank]

When you use the 50mm, do you switch to a different mode versus with the other lens?  It sounds like you have the Mirror Lockup option activated in one of the modes.  But this is not specific to any lenses so by switching lens alone, the Mirror Lockup should not be activated.  If you also switch modes (like Av for this lens versus Tv for other) then it's possible that the Mirror Lockup option is set inadvertently for one of them.

Try using the fully automatic option and see if the viewfinder is still black...in full auto, everything is back to default so options are ignored and therefore everything should work unless there are problems with hardware.

[kvbarkley]

To diverhank's point, does it "clear" when you press the shutter a second time? In mirror lock-up the first shutter press gets the mirror up and out of the way and the second shutter press takes the image and puts the mirror back down.

[KikiSpoon]

Nope, that doesn't work either. It only clears when I actually remove the lens from the body.

[KikiSpoon]

I just tried it again, it acts the same way in all modes even auto.

[Tim]

Hello KikiSpoon, 

If just the EF 50mm f/1.8 II lens is affected, then I would recommend trying the following steps.  

- Clean the lens contacts to restore connection with the body.

**Warning** - Do not clean lens contacts on either a Canon lens or the camera body with an eraser! It's incredibly easy to rub off the gold plating on these contacts, and end up with data communication problems! Our strong recommendation is to use a soft, clean, micro fiber cloth. Again, please do not use anything abrasive.

- Try using a different EF lens (we recommend to try this with a Canon-brand EF lens, doesn't have to be the same focal length as the one you were using) there can sometimes be communication error issues related to certain third-party lenses on EOS bodies and checking this with a Canon-brand lens eliminates this as a possible factor.

If the issues seem to persist the next step would be to send the equipment to Canon for service.

You may fill out a repair request form at the following link to setup your repair using our online service.

http://www.usa.canon.com/repair