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.
Have also uploaded this guide at Instructables
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
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.
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!
 | Nicely done!! I don't think I'll be doing this but good for reference! |
 | ark19 wrote on May 27, '07 Thanks Adam ;)
It's good for ppl with itchy fingers and when the weather is not good for IR shoot :D |
 | Nice work Ark..
I will be in Singapore on 17-23 July, hope the weather is good for IR hunting..
see ya ... |
| ark19 wrote on May 27, '07 Thanks Tony :) I hope so too ;) |
 | Good work and well documented. Thanks for sharing. Doubt I can do this mod myself. :p |
| ark19 wrote on May 27, '07, edited on May 28, '07 Oops, I forgot to add this warning: No Moto Moto staff should attempt this Mod :D |
| hmmm.... must really think of something i can do. kekeke |
 | hahaha, nice tutorial Ark! :) |
| ark19 wrote on Jun 4, '07 |
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