Guide for modding a Cokin P007 to fit into a screw-in filter

[ark19]

Hi guys, been wanting to do this guide for sometime....
Here's the original Guide@Multiply
Cheers!

Summary:
This mod is particularly useful for photographers who shoot IR.
Cokin has an IR filter, the P007. It comes as a square plastic filter and would require Cokin's adapter to be mounted.
However, the adapter would cause light leaks.
This mod shows how the Cokin filter can be cut and sanded into a circle and fitted into a screw-in filter ring.

Note: For the Cokin P series, the largest filter ring size that it can be fitted to is 77mm.

Main material & tools required:
1. Screw-in filter ring (Try to use an old filter or buy a cheap UV filter)
For this mod, I'm using an old 52mm cross screen filter.

2. Cokin P series filter
For this mod, I'm using P007 IR filter.

3. Masking Tape
It'll be used to protect the Cokin filter during the cutting/sanding.
I'm using this Hunter brand. It's quite good as after removal it does not leave any adhesive residues.

4. Dremel
This is a high speed rotary tool. It'll be used for cutting and sanding the Cokin filter.
It's possible to use a saw and sandpaper, but it'll take much longer time.

5. Safety goggles and mask.

6. Small flat tip screw driver.

 

[ark19]

Step 1.
Use a small flat tip screw driver to pry open the retainer spring on the screw-in filter.

This is a close up of the retainer spring. Insert the flat tip screwdriver into the gap and pry the spring out.

Step 2.
Continue to pull out the entire retainer spring.

Step 3.
Now the original filter, retainer spring and the filter ring are separated.
Keep them aside first.

Step 4.
Use the masking tape to tape the Cokin filter on both surfaces.
Don't tape the wordings.

 

[ark19]

Step 5.
Place the filter element on the Cokin filter and trace the edge with a pencil.

Step 6.
Use the dremel to cut as close as possible to the traced line.
Wear the safety goggles and put on the mask before using the dremel.

Step 7.
Use a clamp to clamp the filter element to the Cokin Filter (The picture below does not show the cut filter).
Using a sanding bit, sand away the remaining plastic of the Cokin filter away. The glass filter element will prevent you from over-sanding. A piece wood can be used to prevent the plastic from vibrating during the cutting/sanding process.
You might need to use sandpaper to sand the edges down to fit it into the filter ring.

Step 8.
After finishing the sanding, wash the Cokin filter, place it into the filter ring and install the retainer spring.
That's it!

 

[teerex]

Here's another link to MODDING THE COKIN P007 TO SCREW IN FILTER.
Courtesy:- Ark19.