How to Add Filters and Lenses to Canon SX100is

I bought a Canon SX100is a couple of years ago and always wanted to add filters and lenses to it, like you do on more expensive cameras.
About a month ago I stumbled upon this instructable www.instructables.com/id/Digital_Camera_Lens_Hood_Rain_Hood/ and decided to make something similar for my camera.

- A little plastic cup. It will become our adapter so it has to be just the right size(more on that later)
- An adapter tube designed for another camera. I used a 58mm adapter tube for a Kodak Z712. These sell for about $5 on ebay.
- Some cutting tool. (I used a dremel)
- Flat black paint
-Sandpaper

This step is the most important.
The cup must fit on the outside of the fixed ring around the lens and must be long enough to cover the full lenght of the camera lens.
Also, the adapter tube must fit inside the cup. If the tube doesn't fit perfectly don't worry, you can glue it.
But you can't(or shouldn't) glue it to your camera, so this is the size you have to pay attention to. Check that you can attach the cup on the camera and it does'n fall off.
In my case the cup is about 58mm in diameter and 55mm long.

We have to cut the bottom of the cup. I used a dremel to cut it and to smooth out the edges.
The resulting tube must fit the outer ring on the camera lens perfectly(I can't stress this enough).
So, check if it fits

Now, insert the adapter tube into de plastic cup...
And check if it fits on the camera

Also, check if the camera lens doesn't go over the threads when you zoom.

I sprayed the cup with flat black paint to make it look cool.
Also I scratched out the "Kodak Z712" markings on the adapter, leaving only the "58mm"
After this, check if you get vignetting(darkened corners) on your pictures. You shouldn't get them.
If you do, that's becouse the tube is too long, you should make it shorter by reducing the lenght of the plastic cup.(more on that later)
I didn't get vignetting at this step

Now you can add filters, lenses and accesories to your SX100is.
I bought a circular polarizer filter, a +8 close-up lens and a lens hood.
I bought them online from some chinese website, for about $6 each.
I also bought a Raynox DCR-250 macro lens.

I was getting a little vignetting using the polarizer at wide angle. I needed to make it shorter.

I also got vignetting with the macro lenses, but those are meant to be used at full telephoto, so I didn't care. But the polarizer can be used to take pictures of landscapes so I needed to get clean pictures at wide angles.
So i layed a piece of sandpaper flat on a table and started rubbing the plastic end of the adapter against it.  You can see that now the lens gets closer to the threads. It needs to get closer to the edge, but not over the threads!
This step is a little trial and error. I started rubbing it on the sandpaper and checking my lcd for vignetting, then rubbing again until I got a clear picture. I ended up sanding off about 2mm.

That's it. Now you have a fully functional lens/filter adapter.
Go and start taking pictures!

I took this picture with my raynox macro filter, it's a black ant biting on a cardboard box.