Cutting filter glass for camera IR or full spectrum modification

Upon preparations for my Sony A6000 camera full spectrum modification, I didn’t find any reasonably priced IR-filter replacement. Most of the offerings I found have been way above any reasonable price. So I decided to try cutting my filter replacement myself…

I did some research on cutting filter glass. Most of the guides I found used window glass cutters to score and break the glass apart. This technique is in my opinion perfect with most ordinary glasses. Though filter glass, which is hardened and coated does not break evenly. You seem to get very rough edges, which would not be in acceptable tolerances for me. Cutting a larger piece and grinding down to desired size would be the only option with this method.
An other method I found for cutting glass (in general) was, to use diamond plated cutting wheels. All the results I have seen, provided nice cuts. So this should be the technique to go for…

I previousely did use 1 inch diameter diamond cutting wheels on several occations. But for cutting a nice and clean line, I purchased a set of 50mm diamond plated cutting wheels with less than a millimeter thickness. These were available online for less than 10 EUR.

Preparations and cutting:

The easiest way to mark the outline of the desired filter is, to stick a strip of masking tape on both sides of the filter. This has two benefits:
1) you can easily mark the lines with a pencil or waterproof pen
2) the surface of the filter is protected against scratches and durst

Now research the dimensions required and draw the rectangle on the tape. When you are done, go to your sink, take a medium sized flat container and fill it with water to approximately 1 cm level. Attach the cutting wheel to a battery powered electric drill (water + electricity is too dangerous!!!)
Use a very low speed to turn the cutting wheel. Now dip the filter in the water and bring it with very low pressure to the cutting wheel. Cut all four edthes from one corner to the other. Cutting is impressively easy and fast. Results are absolutely pleasing 🙂