cokin filter?

hello i red on here the other day about cokin filters in a thread which i cant find now they enhance the sky or something : any clue where i see this or advice on filters please
thankyo

Was it this one?

hi emma,think you are looking for a circular polarizer,regards steve

hello thankyou for replying been doing some more research think it is a circular polarizer im after

Here is a photo taken with my polarizer on my K20 Sigma 10-20 lens is this what you are looking for,
Jack.

https://www.pentaxuser.com/photo/looking-to-malaga-5811/large

yes thats it is this a cokin filte or hoya do one i was just looking at on srs

Hi Emma, it's a Hoya you can get them on Ebay at a reasonable price depending on what size lens you want it for, if it's for a wide angle lens make sure it is a slim fit.
regards,
Jack. happy to have been some help.

Emma please do some more research since there is a big difference between a graduated neutral density filter (GND) or a polarizer filter (pol).

The square filter system like the Cokin are very good for the GND since you can determine where the transition (horizon) is since you can move the filter inside the holder.
For the pol I would get a screw-in filter they are simpler and far more user friendly. A Hoya or B&W are most likely also far better then the Cokin pol.

One can get circular filters to fit the square systems. For me this is the way to go, but as above,if you intend to use very wide angle, say less than 16mm get a large holder, or vignetting may occur.

Davex.

Hoya polarising filters seem to be pretty cost effective - it is not crucial to get a circular polarising filter, a linear polarising filter will also work on Pentax DSLRs despite what many people will tell you!

Linear ones look exactly the same, and can often be got for much less money because they apparently cause problems with some other brands of camera, and there is a general perception that they don't work with digital. For example, I got a mint second hand one for a fiver

It might be the way for you Davex but I've my pol filter on almost 100% of the time. The holder you need for the filter makes the lens front heavy and also longer and wider then with a screw-in.

Also buying a square system filter for just a pol seems a bit silly to me when a Hoya or B&W are better and just as expensive as buying a holder and a pol filter and the rest what you need for a square filter.

For saving some money you can buy a 52mm pol that fits straight on the 18-55 and use a 52mm to 49mm stepdown ring so that you can use the 52mm pol on a 49mm filter size.
The 50-200 and the macro are 49mm and also the 50mm I believe so you cover 4 lenses with just one filter.

I can see your point Stefan, but have to disagree;if Emma goes with a screwin pol then decides she wants to combine with an ND Grad or some other it is going to be a pain. I think it much better to start off with a proper system, which can be adapted rather than messing about with bits and bobs.

This is a good point but equally aplies to a square system.

My thoughts, for what they are worth, are thus;
If you want to try a pol go with Stefan`s suggestions, unless you think you may wish to try other filters, in which case get a square system. Incidently, while you should always get the best filters you can afford the holder and stepping rings can be bought off ebay much cheaper. try here.

Davex.

I don't see the problem there.
What is the difference in the pain of using a Cokin pol or a screw-in pol?

I've used the Cokin Z-pro with a screw-in pol without any problems you just need to have a finger on the pol if you turn the holder.
If you have pol inside the holder then when you turn the holder you need to re-adjust the pol again so it might even be handier to have a pol screw-in pol then a Cokin pol.

To be frank, the days of filter systems are probably numbered. If I were starting out now I would buy a 77mm filter and step down rings to fit my various lenses.

G

This is certainly true for the K10D (and, I'm sure, Emma's GX10).

I have both screw-in, and Cokin P linear polarisers, which I thought I'd try out first before getting the CP that almost everyone insists you need.

They're absolutely fine - since getting the K10D in Jan 07, I've never known any issue with either the metering, or the AF, either or both of which are supposedly affected. And I have looked quite carefully for such an issue.

Saved me a lot of money - good CPs are expensive.