high ISO with red filter

great visibility these days in sydney. it seems that the port jackson sharks are arriving. Here is a photo of an eastern blue devil fish we saw at shark point (sunday may 18).

i tried using high ISO with a red filter at 25-28m depth. With ISO set to Auto the speed would go down to 1/5 (shutter priority mode with speed set manually to 1/60, and aperture 2.8). i manually set the ISO to 800 to get good exposure speeds (at ISO 400 still there was not enough light). At 25-28m with ISO set at 800, i would get exposure speeds around 1/30 or 1/25 which is ok along with the image stabilization to avoid too much blur.

there is plenty of noise in the pictures. simple filters (such as the ones i use with picasa) will have trouble fixing the colors due to noise (following photos tint filter with 60-70% color preservation and the original next to it).