Shutter Speed - Pentax Optio S4i

Hi -

I recently purchased the Optio S4i. Am generally happy with the camera as I'm not an avid photographer and just wanted something small and compact to carry around. In this respect it passes with flying colours and some of the general pics aren't bad either.

I have one issue though and am hoping that there is some way that changes to the camera settings can be made forcing the shutter speed to increase to capture quick movement - I am aware that it is automatically done. There isn't any preset option for action shots and this is dissapointing as I would like to take pics of my fish that generally zoom around and I'm getting quite frustrated with the resultant blurred images I'm getting.

Could anyone please provide some hints and tips for me to take action shots with this particular camera?

Thanks in advance.