It appears that the 6d s shutter assembly is whats it is and nothing that firmware can alter.
Canon 6d setting shutter speed.
When you take pictures in shutter priority mode you choose the shutter speed and the camera supplies the proper f stop value to properly expose the scene.
Silent single drive similar to the first setting but the mirror is raised slower for less noise.
With shutter speeds of 1 3 seconds or slower there will be a delay before you can shoot again as images are processed to remove noise.
When shooting at low shutter speeds on a tripod you should set is mode to off.
You can choose how the canon eos 6d meters a scene to determine the exposure.
Continuous drive pressing and holding the shutter release button will continuously fire the camera at a speed of 4 5 frames per second.
That s gonna change your shutter speed.
Aside from the lower max shutter speed the assembly is rated at 100 000 actuations instead of 150 000.
The eos 6d s exposure settings such as aperture shutter speed and iso focus and shutter can be operated wirelessly using an ios or android smartphone with the free canon camera connect app.
Again this is what i ve read on forums like this one i have not verified it first hand.
Your camera has a shutter speed range from 30 seconds to 1 4000 of a second.
Your camera s metering device examines the scene and determines which shutter speed and f stop combination will yield a properly exposed image.
If you re in live view mode you can see the shutter speed changing as well.
Your manual will tell you whether it s 1 200 or some other value but to date i don t think any canon body goes above 1 250 when working with a flash in the normal manner.
Auto racing at 1 400 seems a bit high to me but i suspect the problem is that a 6d s max sync speed for using a flash is 1 200.
When your goal is to accentuate an object s motion with your eos 6d choose shutter priority mode.