Combining filters?

[kdoc856]

I was recently shooting some water falls early in the am. As the sun came up, I added a grad ND filter as my scene included both falls and sky. A little later, the sunny day was giving a fair degree of reflection off the water, and I thought of adding a polarizing filter. Logic would have it that the more glass i throw in there, the more image degradation I'd get, so I didn't do it, and didnt have the time that day to experiment with it. Anyone have any thoughts or experience with this?

Thanks, Kevin

[jeeperman]

I have at times combined filters without any noticable degree of degradation. Slight if any. The one thing to be aware of though, if you use screw in and not slot in filters.....stacking many times results in vignette in the corners. If you use a couple of slim line filters you may avoid this.

[kdoc856]

Thanks, Paul for the feedback. I have certainly experienced the vignetting you refer to, and have become very careful to use slim line filters whenever possible. I'll experiment with the combo, as i shoot a fair amount offlowing water and could use some enhanced light limitation on brighter days

[Colin Southern]

Hi Kevin,

Image degradation with quality filters is pretty much a myth. I'm sure someone / somewhere will be able to "prove it", but as far as I'm concerned, if you can't actually SEE the degradation then it doesn't count. When you think about it, if you were adding a 2nd filter to provide some effect, then NOT adding it will probably degrade your image more.

If you're going to combine a CPL and GND, the "trick" is to hand hold the GND, so the holder doesn't increate the vignetting (I'm assuming you're using 6 x 4 flat GNDs); for longer exposures you can secure them with rubber bands or a bit of tape.