A friend of mine told me that in Canon 5D Mark III while shooting in AV mode (No matter what time of the day), U can choose a setting where camer's shutter speed will not go below 60/sec , 125/sec, 250/ec ect
I kind of figured out that option in 5D Mark III and had set my shutter speed to 125/sec..and ISO on AUTO to get the perfect exposure..but still in some shots the camera jumps below 125/sec
Have anyone used that setting on 5d MArk III and how can I do that..so no matter if i am shooting at day time with wide open at f1.4 shutter sheep should always be above 125/sec and even in night with auto ISO..it should maintain 125 +shutter speed.
Go into ISO settings and you'll see an option to set the minimum shutter speed.
You probably have to make sure that Safety Shift is off or set to ISO.
You may be able to achieve your goal better by setting the ISO to 100, the minimum shutter speed to 1/125 and setting Safety Shift to ISO. What will happen is the aperture will go to what you've set, the shutter will be at 1/125 and the ISO will fluctuate to make the exposure that you've set with exposure compensation.
Keep in mind if you add a flash Auto ISO goes to 400 fixed or 1600 if you've set the speedlight to bounce.
If you use manual with auto ISO you can do the same thing you want, but you won't have exposure compensation controls. It's a huge screw up on Canon's part.
This is one of the reasons to have a 1D body since you can set shutter speed and aperture ranges.