Does your camera pick a slower shutter speed when IS is turned on

Hi peeps,

I love this forum becoz everybody is so helpful.
I have a minor issue with my 550D at AV mode. Im using 70-200mm f4 IS with it. Regardless of whether the IS is on or off, the camera tries to picks shutterspeed of around 1/250s with auto ISO at F4.
The thing is i know the 70-200mm F4 IS can perform reasonably well handholding it at 1/60s. Why cant the camera tries to get 1/60 at F4 and lower the ISO. Its quite noisy when the camera always pick 1/250s and pump up e iso to compensate. I can always use manual iso but it wld be nice when the camera knows IS can do 1/60s.

You should probably stick with setting the ISO by yourself. This problem seems fairly trivial.

You have a 550D! If you don't want your camera going too far into high ISOs and feel comfortable shooting lower shutter speeds, just set the "Max ISO" for Auto ISO to something lower silly!

The camera is programed to make certain decisions when you use auto modes. The solution when it's doing things you don't want it to do is to stop using the highly auto modes.

There are three sides of a triangle to consider to get a good exposure; ISO, shutter speed and aperture, which I am sure you know already.

The problem you are having is that you are only fixing one side of that triangle, the aperture, and allowing the camera to juggle the other two. Is it any surprise that it doesn't choose something to your satisfaction.

If you are not comfortable shooting in full manual mode, the next best step is to fix two sides of the triangle yourself, ISO and aperture in your example, and let the camera juggle just the shutter speed to balance the exoposure.

Don't use auto ISO

Use the lowest ISO you can to give the shutter speed and aperture you require.