Polarizing filter and Cokin Z-Pro Series holder: need users advices

Hi everyone,

I am looking at purchasing a polarizing filter.
I will mainly use this filter for waterscapes, using the low shutter speed method. I before used srew-in filters. But I replaced these by the Cokin Z-Pro series holder with HiTech ND0.9, ND1.2 and graduated ND0.9.

The main problem is that the dedicated polarizing filter for Z-Pro series holder is not really cheap (250 €). Furthermore Cokin seems to have some problem and stocks are not filled.

Then, I am considering two solutions:
- Screw-in filter UNDER the holder: need an external thread and to be thin, like the Hoya Slim or Hoya Pro1 Digital (http://www.hoyafilter.com/products/hoya/pro1d-04.html)
- HiTech square polarizing filter from HiTech (105mm x 100mm - http://www.formatt.co.uk/stills-filters/filters/polariser/105mm-circular-polariser-filter.aspx).

As I easily guess I am not the only one using a polarizing filter with an holder, I would like some advices or reviews from users about these two possibilities
I will use it with the following gear: Canon 7D + SIGMA 10-20mm, Canon 24-105mm, and Canon 300mm.

Thank you very much

David

I use a Hoya Pro1 polarizing filter and have been quite pleased with it.
My only advice is to not use the polarizing filter on your ultra wide angle lens if any sky is included in the image, as you're guaranteed to get uneven polarization of the sky, and that is not a pretty thing.

Thank you John.
So you use Hoya Pro1D under your filters-holder. Is it easy to use (rotation of polarizing filter) when your holder is screwed on?

I am searching for information about HiTech polarizing filters, and there is something I do not understand:
What is the difference between:
- Hitech 105mm Kaeseman Circular Polarizer Glass Filter
- 100x105mm Circular Polariser Filter (still filters).
?

Thanks for your help

I just tried John's suggestion of putting the polarizer under the filter holder. I have the Cokin P holder and, as it happens, the Hoya Pro1 D polarizer.

I didn't find the polarizer that easy to rotate, but it's definitely doable. It's not that easy for me to rotate the polarizer that fits in the Cokin polarizer slot either. In fact, with one of the two holders I own, it's extremely difficult to rotate the polarizer. I've even gone as far as using a hacksaw to try to widen the slot. No help, though.

John's idea provides another benefit. Using a circular polarizer under the filter holder allows me to use the 1-slot holder for a grad. The 1-slot holder creates slightly less vignetting than the 3-slot holder. With my Canon 17-40 lens, the 3-slot holder creates vignetting until I zoom out to 24mm. With the 1-slot holder, the vignetting disappears at 22mm. Not a lot, but something.

I should add - my good friend Richard Bernabe has stopped using grads and urges me to do the same. Richard does it with blending exposures in PS.

Thank you Lance for this review.
So I will purchase a Hoya Pro1D filter and manage with it.
As it is for waterscapes, I don't mind if I need "some minuts" to set up the polarizing filter... It will not flee away