Are there any secrets to stacking a ND 3 filter on top of a CP filter ? anything i should know i have never tryed it? do they have to be perfectly aligned and can this be done on zoom lenes?
At a waterfall a couple weekends ago I stacked a 4-stop solid ND on a Heliopan CP that I think is about 1.5 stops equiv. First I took a couple test shots with only the CP to get a balanced exposure and critical focus then backed the shutter speed off 4 stops, applied the ND and nailed it; The results was what I had envisioned. Not a great scene per se' and it's still in the camera. When I get it processed I'll probably post it in the PNW forum. It was a somewhat bright day and this is a good technique to slow down water when you want to. Not sure if this was what you were looking for but there's my take on it.
Posted by David Bostedo on June 25, 2012 at 12:25 AM
Are there any secrets to stacking a ND 3 filter on top of a CP filter ? anything i should know i have never tryed it?
No secret or trick... your filter stack just gets longer. Since an ND is a solid color across, there isn't anything special about it. The polarizer will have to be able to be turned as usual, so I've usually put that one on last - I think it makes it a bit easier, if you're talking about screw in filters. But it doesn't really matter.
The main thing to watch out for is vignetting... as the filters extend further out from the end of the lens, the corners of your image may get cut off; And they'll almost certainly show a little bit of darkening, which is easily corrected if that's all you see.
do they have to be perfectly aligned...
Both an ND and a polarizer will affect the whole scene equally (although the polarizer may show a changing effect across the frame - but you can't change that). So no, there's no alignment to be done. If you're talking about a GND filter, and you're using a polarizer, getting the grad line and polarization turned right might be a problem? I don't know, having never used a GND.
...and can this be done on zoom lenes?
There is no issue with zoom lenses, other than certain focal lengths will vignette a lot more than others, depending on the lens focal length and construction.
The only "trick" I know if is to match brands, or at least to use good quality versions of both. I've experienced color shifts (usually to the olive/green side) with a bad mix of the two. Easy to check before you go chasing critical shots, and I'd surely do so unless you're facile at color balancing in post.
Posted by Kent Staubus on June 25, 2012 at 8:45 AM
I would also make sure the sun doesn't hit the filters, if possible.
Discussion
4 repliesNo secret or trick... your filter stack just gets longer. Since an ND is a solid color across, there isn't anything special about it. The polarizer will have to be able to be turned as usual, so I've usually put that one on last - I think it makes it a bit easier, if you're talking about screw in filters. But it doesn't really matter.
The main thing to watch out for is vignetting... as the filters extend further out from the end of the lens, the corners of your image may get cut off; And they'll almost certainly show a little bit of darkening, which is easily corrected if that's all you see.
Both an ND and a polarizer will affect the whole scene equally (although the polarizer may show a changing effect across the frame - but you can't change that). So no, there's no alignment to be done. If you're talking about a GND filter, and you're using a polarizer, getting the grad line and polarization turned right might be a problem? I don't know, having never used a GND.
There is no issue with zoom lenses, other than certain focal lengths will vignette a lot more than others, depending on the lens focal length and construction.
Kent in SD