6D problem, all my lens diaphragms dont close or open

[zero]

With my ef 50mm stm , I try to use it with f-stop: f/20 , normally the diaphragme must be visible ( because it is closed) , in my eos 6d, the 50 mm and the 28-135 mm lens diaphragmes are widely open(diaphragmes not visible). How can I resolve the problem please?

[cicopo]

Your camera stops the lens down when TAKING the photo. It keeps it wide open for focusing. There should be a button you can press to see it stop down. (check your manual for the location.)

[zero]

Thank you very much for your reply, I now understood as it works.

[ebiggs1]

It depends on the lens.  It should be open while focusing.  You can not stop it down until you set something on the camera.  Canon lenses do not work the same way as some Nikon lenses do.  They must be locked at minimum aperture to work.

As the previous answer says you have a DOF preview button somewhere on the camera which allows you to see the lens stopped down to f20.

 f20, is there a reason to use f20?  Just curious.

[zero]

Juste to test ,that all is OK ?

[ebiggs1]

Certainly OK. It is just not a commonly used f stop.

[zero]

Yes