Cokin system filters - suitability for digital?

I've had a read of threads passim and I think I follow, but I'd appreciate some clarification and confirmation.

I have a K10D and *istD and would like to use my old Cokin A series filters on (predominantly) the 18-55 lens. I'm hoping mostly to use the polariser to liven up some pretty limp skies, and occasionally a neutral density when shooting off a tripod with long exposure (the *istD goes to ISO200 only).

Am I right in thinking the vignetting is less pronounced than for 35mm cameras? I didn't really struggle that much, save for when I borrowed an old 24mm Tamron adaptall, but not sure how it'll work at the 18mm end. Are there any vagaries or technicalities I should be aware of when using polarisers with wither body? I'm not clear if the sensors have filters which may be impacted, or I'll do something undesirable to metering or AF - I recall the AF requires a certain type of polariser.

all advice gratefully received - it's been a while since the filters have seen the light of day, and I'm still not quite up to pace on the digital!

Hi Mattie

Cokin works fine on digital - I use the P rather than A but that's just down to the size of the lenses I use really.

One word of caution though - if you intend using an old polariser - make sure it is circular an not linear - most of the old PLs for film were linear but digital SLRs really do not like these at all.

I haven't really noticed much difference it terms of vignetting between film and digital

Personally I use screw in polorisers and mainly use my Cokin system for NDs and ND grads.

regards
Carl

Thanks Carl - the polariser is circular. I believe the linear messes the AF, glad it works the same way for the image sensor!