My old 10-20 was 77mm thread.
Newer ones appear to be 82mm.
http://www.warehouseexpress.com/buy-sigma-10-20mm-f3-5-ex-dc-hsm-nikon-fit/p1032429
+1 on Formatt Filters..
I have a set of soft ND grads and use them all the time. No complaints so far in 5 months.
If you want to shoot at 12mm or less you will require the wide angle holder which only has one slot or you will suffer vignetting
It's confusing me as I don't know which filter size to use, whether I need a wide angle holder etc.
Anyone have this lens with filters?
It's confusing me as I don't know which filter size to use, whether I need a wide angle holder etc.
Anyone have this lens with filters?

To avoid vignetting you will have to buy the cokin p wide angle holder unless you shoot above 12mm.
Hi, i have the 10-20 with the 77m filter thread. I use the 85mm Formatt filters with Cokin P holders/adapters. The 85mm filter slots perfectly into the Cokin P Holder, the adapter ring is 77mm to screw onto end of lens then the holder slides onto that.
To avoid vignetting you will have to buy the cokin p wide angle holder unless you shoot above 12mm. If you would like to use multiple filters together you would have to go for the 100mm Formatts, not sure about the holders because i only use the 85mm.
Basically the 85mm on wide angle holder just clears the frame so obviously multiple filters at once would be seen easily, if i put my Hoya Pro-1 circular polariser (very thin) on then add the wide angle holder there is a little vignetting at 10mm but its clear by 11.
Hope this helps and makes some sort of sense![]()
Hi, i have the 10-20 with the 77m filter thread. I use the 85mm Formatt filters with Cokin P holders/adapters. The 85mm filter slots perfectly into the Cokin P Holder, the adapter ring is 77mm to screw onto end of lens then the holder slides onto that.
To avoid vignetting you will have to buy the cokin p wide angle holder unless you shoot above 12mm. If you would like to use multiple filters together you would have to go for the 100mm Formatts, not sure about the holders because i only use the 85mm.
Basically the 85mm on wide angle holder just clears the frame so obviously multiple filters at once would be seen easily, if i put my Hoya Pro-1 circular polariser (very thin) on then add the wide angle holder there is a little vignetting at 10mm but its clear by 11.
Hope this helps and makes some sort of sense![]()
I'm surprised the normal holder stops vignetting by 12mm on DX - on full frame it vignettes from about 28 mm or wider(with a 24-70), so I would of thought it would still be an issue throughout the lens' range?
Great, thanks. Are you happy with the results you get from just one filter?
Makes perfect sense. Exactly the info. I was looking for too.
Cheers.