Adapting circular polariser for cokin P

[lbrodziak]

Hello,

I have a set of 62mm Hoya filters (1 CPL and 2 ND) I would like to get a square Cokin P121F NDx8 along with a holder and 62mm adapter. The thing is I would like to combine all four together. With NDs there should be no problem I will simply srew the adapter onto ND filter and Bob's your uncle, But there is a problem with CPL, for obvious reasons. Does anyone know if there is a way of combining a screw-on Cir-PL and Cokin P holder?

[Black Pearl]

Firstly the image quality drop from combining four filters (eight surfaces) is going to be noticeable to say the least so your basic idea isn't a strong one. If you absolutely insist then you could still use the CPL on the lens with the Cokin adapter screwed into it turning the entire Cokin holder to set the CPL.

Would you not be better off just buying a single high density ND filter?

[Dave Humphries]

I agree with Robin's image quality concerns, but would add that, unless the lens is telephoto, you are liable to see significant vignetting when stacking more than one screw on filter.

Warm welcome to the CiC forums from me.

Could you do me a favour please?
Could you click Settings (right at the top),
then Edit Profile (on left)
and put your first name in the Real Name field
and where you are (roughly) in the Location field,
then click the Save Changes button below and to right,
this helps everyone give you more personal and relevant answers - thanks in advance.

Cheers, Dave

[lbrodziak]

Yes I know about vignete and image quality loss but I don't mean to stack up 3 screw on filters plus Cokin system, which I admit would be crazy . The problem is using Cokin P + P121F which is an ND Grad with my CPL because when I will twist the CPL the grad will also twist.

I also edited the profile as You asked

[Stagecoach]

Hi Lukasz,

Screw your CPL onto the lens and screw your Cokin P 'adapter' into the front of the CPL (assuming CPL has female thread).

The Cokin filter holder will rotate on the Cokin adaptor screwed into the lens easily (at least mine does).

For ease of use you can rotate your CPL first to where you want it, then carefully slide the Cokin holder onto the adapter, carefully keeping it square should you be using a Grad ND.

[dje]

Yes I know about vignete and image quality loss but I don't mean to stack up 3 screw on filters plus Cokin system, which I admit would be crazy . The problem is using Cokin P + P121F which is an ND Grad with my CPL because when I will twist the CPL the grad will also twist.

I also edited the profile as You asked

Lukasz I don't know about Cokin but Formatt-Hitech make an adapter that mounts on the front of their square filter holder and it can be used to mount a CPL in the very front of the assembly. See here. You might be able to use a Formatt-Hitech holder with your Cokin filters, you'd have to check the thickness.

You do however need a fairly large CPL (95mm for an 85mm square holder) and these are probably fairly expensive.

Dave

[lbrodziak]

Hi Lukasz,

Screw your CPL onto the lens and screw your Cokin P 'adapter' into the front of the CPL (assuming CPL has female thread).

The Cokin filter holder will rotate on the Cokin adaptor screwed into the lens easily (at least mine does).

And this is the answer I simply didn't know I could rotate the holder on the adaptor Guess Read The Manual First rule applies here thank you for your answer Grahame.

Also thanks go to everybody else who provided an insight on this thread

[Dave Humphries]

Hi Lukasz,

I'm glad you found an answer here and I hope you continue with your membership here.

We're all here to learn and help each other out.

Cheers, Dave

[Black Pearl]

Yes I know about vignete and image quality loss but I don't mean to stack up 3 screw on filters plus Cokin system, which I admit would be crazy . The problem is using Cokin P + P121F which is an ND Grad with my CPL because when I will twist the CPL the grad will also twist.

I also edited the profile as You asked

Replace your current screw in CPL for the Cokin version which sits in the very rear slot of the holder and spins within it. This means your GND can go in one of the front slots and work together as one coherent unit.