A Round Sprocket Cokin P173 Blue Yellow Filter
I originally shared this on the now retired How to Photograph the Canadian Rockies weblog but it has enough value to publish again. The following steps may help you better use Cokin’s Blue/Yellow Polarizing filter.
If you are like me, you bought the Cokin P173 Polarizer and received it in a square plastic casing. You placed this filter into the Cokin-P holder, rotated the polarizer to the desired strength and then found yourself scratching your head because it was now near impossible to add a graduated filter. This limitation alone was a primary reason why my P173 filter found a permanent home in the camera bag. I actually had it listed for sale until I told Darwin Wiggett my frustrations. He happens to know a thing or two about photography and suggested this fantastic solution, but first, let’s pause for today’s photo.
Today’s Image – Island Cliffs
A thin strip of Prince Edward Island coastline intersects two equal halves of the clean and competing colors in the sky and water. In the distance are the sand dunes of Cavendish. I’m not typically a fan of a clear sky but sometimes no clouds can be acceptable and for a very windy location like this, it takes a long 20 second exposure to make even the best of days look calm.
Back to the filter mod.
How do you use the Cokin P173 Blue Yellow Polarizer?
Let’s first start by showing the problem. Who knows why Cokin believes this was a good idea. Using this filter alone would be fine by rotating the entire holder but it all falls apart when you want to slide in a graduated filter.


Step 1.
All you need is the $25 plastic Cokin Star filter. This filter will come in the round sprocket case designed for the Cokin-P holder. I bought the P056. You can easily split open the case that the P173 comes in without breaking the holder.


Step 2.
Push out the P056 Star Effect filter from the case it comes in.

Step 3.
Push the P173 Blue Yellow filter into it’s new round holder – A perfect fit.

Step 4.
You now have a Blue Yellow filter that spins independently of any grad filter you use in your Cokin-P holder. However, it’s still an acquired taste and a filter I rarely use.


For a filter I only use on the very rare occasion, this setup at less than half the price of the Singh-Ray equivalent. I have never used Singh-Ray’s version or do I know of any specific quality differences. However, ignorance is a blessing and this setup is more than good enough to recommend.
Don't miss the next post. Subscribe to this photoblog by Email or by RSS

Beautiful. Great image.
[...] blue/yellow polarizing filter is something I rarely use but when I arrived at the beach and realized I had forgotten my standard [...]