Please help!! Sigma 12-24mm CPL

[EGC]

I use this lens mainly on my 350D, sometimes on my film EOS 30...

I REALLY REALLY want a CPL (a must for landscape shootin and proper exposure) however:

1. 82mm cpl is relativly rare...
2. EXPeNsIVE!

i'm lookin at Hoya's 82mm, which are priced at £30/£90(Ultra-Slim) on eBay, and £60/£180 at Jessops...

my questions... do i need to spend the extra cash on UltraSlim? or is there a Gelatin CPL (rear filter) for this lens? if so where can i buy one?

please please help... a landscape lens without CPL is nothing.... :(

[Jon]

Absolutely forget about a CPL for use on that lens with the EOS 30. Even the 82 mm will cause vignetting. You'll notice that it's got a built-in butterfly lens hood, which is designed for FF use. The 82 only fits on the slip-on circular (and you're right, you would need a slim CPL on that) hood.

However, I think you're overlooking a significant problem you'll have using CPL on ultra-wide angle lenses (which describes the entire range of this on a FF body; the 12-17 mm zone on an APS-C). Maximum polarization occurs on a band at right angles to the sun's azumith/altitude. With too wide a lens (see above),you'll incorporate areas well outside this and consequently see significantly less polarization on some parts of the sky than on others. You'd be better off looking at a large ND grad filter instead.

A rear-mount gel filter would be problematic at best for either a CPL or a ND grad, as there's no way to adjust them short of removing the lens.

[EGC]

thanks John... do you think i can use GRAD gray with Cokin Ring 82mm on it?

[EGC]

i was saying the Cokin X-Pro 82mm Ring + Set of 0.3-0.9 ND Grad Filters
some of my friends also mentioned Lee 82mm WideAngle rings... any differences between lee and cokin ? price? quality?

thanks

[Jon]

Again - you can only use an 82 with the auxiliary hood, so not with the EOS 30. I use Singh-Ray ND grads. (http://www.singh-ray.com/grndgrads.html). They're made to order,and go in a square filter holder so you can adjust where the gradient falls. I can just barely get away with the Cokin P holder with the first set of guides cut off (it's got guides for 2 filters) on my 15-30 on the 20D (also82 mm dia.) The Lee (4") holder would probably be better for something that wide.

[EGC]

thx again jon.. i'll go to the camera shop for another try tmr...

[MrChad]

??confused??:confused:

You can't use a screw on filter with the Sigma 12-24mm? (it's almost like fisheye lens) It takes gelatin style filters, how do you polarize that?

[EGC]

??confused??:confused:

You can't use a screw on filter with the Sigma 12-24mm? (it's almost like fisheye lens) It takes gelatin style filters, how do you polarize that?


no i can't... i can use screw on filter on the adapter that came with the lens, but only from 16mm +...

im thinking to buy cokin x-pro ring + filter holder, hopefully it'll do the trick.

[Hmood]

EGC :
Any updates on cokin x-pro ring + filter holder ? I have the same lens ( Sigma 12-24mm ) . Please advice.