Filters on Sigma 10-20

[tumblew33d]

I'll be taking delivery of a Sigma 10-20 tomorrow and would appreciate some advice on filters. I've done a lot of reading and read a lot of differing opinions on vignetting when using ND Grads and blotchy polarisation with CPL filters when going as wide as 10mm.

I have a set of Hitech ND grads (P sized, 85mm) and a Cokin wide angle holder (single slot) which I use down to 17mm with no problem. From what I've read, some say that this will work fine at 10mm, others say "must go bigger". I don't intend to stack or use the CPL with ND grads. It'll be single filter use only.

As for CPL, I use a Kenko Pro1 with satisfactory results at 17mm. How much harder will it be to avoid uneven saturation and blotchiness at 10mm? Would I be better sticking with ND Grads and not bothering to buy another CPL for the Sigma 10-20? I could sell my Hitech filters, Cokin Holder and 67mm CPL to fund a Hitech 100 set and invest in a 77mm CPL with step down for use with my other lenses.

Obviously there's the HDR and exposure blending option along with digital grads in CS and Lightroom but I'm more interested in using physical filters.

[rklepper]

I think you will at least need the Z size (100 mm).

[CronoDL]

I have the Sigma 10-20 and I use Hitech ND grads with the Cokin P wide angle holder also. There is no vignetting with the filter in its usual vertical or horizontal positions. However, when it's rotated to about 45º or so, I do get black corners. But it's rare that I rotate it into such a position so it's not a big issue. I have to mention that I'm a Sony user, so it should be less of an issue on Canons because of the crop factor.

As for the polarizer issue, I have to admit that I haven't even tried one on my 10-20. Being that the lens covers such a wide angle, there will be times where you will get uneven blues in the sky, but whether that's a problem or not depends on the particular shot.

[tumblew33d]

Thanks for your replies guys. Danny, I've never had a need to rotate my ND grad filters so I'll probably give my current ones a go for a while and wait to see if I miss not having a CPL for the lens.

Thanks again.