Intro: DIY Star Filter
I recently bought a Canon SX10 IS and it's an awesome camera. After I got CHDK running the only problem I have is that I can't put filters on it. There are adapters to let you use them, but until I get enough money to buy it, it's no filters for me.
I love the effect star filters give. I looked around and found a home made one on Flickr but there weren't any instructions on how to make it, so I figured I would make an 'ible showing how I made it. Credit goes to Rey Nocum for the original idea, you can find his page here http://www.flickr.com/photos/reynocum/sets/1804553/
*Please note this will work on any camera/slr lens that you can attach a lens hood to.
Step 1: Materials
There isn't much you need for this. I'm not really sure how much this costs because I had it all lying around. I know it shouldn't be more than a few dollars.
*Metal screen (the kind used in windows)
*Pringles can/empty tape roll
*Utility knife (not needed but its easier to cut the can with)
Step 2: Cut It, Fit It, Tape It
First, you need to figure out how big your lens is so you know how big to make the filter. The easy way to know if you need the can or the empty tape is to slide the Pringles can over your lens if it's too big than that's what you'll use. However, if its too small try the tape.
To give you a basis of comparison my lens is 58mm and the can was too wide, so the can can accommodate a lot of lenses. The original by Rey Nocum was made out of an empty tape roll and his lens is 85mm (googled the model number on his lens hood)
Once you know what material your using, cut a strip of the container about a half inch thick or so (if using an empty tape roll it might be narrow enough already).
See it it will slide into the lens hood, if it's too big, as it should be, then cut out a small section and try fitting it again. You could measure it and cut once, but guessing and checking is probably faster.
Once you have it at the right size seal the seam with a piece of tape.
Step 3: Screening Time
Now that we have the ring we can make the filter itself. According to Rey Nocum it needs to be shiny and the finer the wire the better. So i used generic metal screening. We had plastic, which would be safer for the lens, but it was dull and had thicker wire.
Trace the inside of the ring on the screen, then trim away the extra screen leaving some space around the traced circle (see images) so we can make flaps.
Once you have it trimmed cut notches into it so the screen doesn't wrinkle when it gets folded. Then, fold the flaps up (see final picture).
*Please note you will need two of these screen circles if you plan on making an 8 point star
Step 4: Almost There
It's almost done. Slide the screen into the ring and using a piece of tape secure it to the ring. Then tape the flap opposite the one you just did and continue this pattern (I found this was the easiest way, but you can tape the flaps down in any order).
*Please not if you use some hot glue it will hold much better (thought of it too late to use on mine so there are no pictures or instructions, but I'm sure you know how to hot glue something).
If you are making an 8 pointed star then you need to tape (or glue) down the other screen over the first. Also, remember the wires in the second screen have to cross the first screen's wires at a diagnal
ie if the first screen is going this way + than the second should go like this x (see the last 3 images)
Once you have the whole thing taped down (or glued), test fit it in the lens hood. If it fits then all you have left to do it put some tape on the outside just to give it a slightly more finished look and protect the hood from scratches.
Step 5: And That As They Say Is That...
That's it. All that's left to do is slide the filter in the hood, attach the hood to the camera and take some pictures.
I just took a 2 quick test pictures to see if they work. They do.. I would guess the haze is the glare from the direct sunlight on the filter (its meant to be used at night) in combination with having something covering the lens. I plan on taking some more test photos at night (might not right away so it might be a while before I put new examples up). Again thanks to Rey Nocum for the idea you can find his original filter at http://www.flickr.com/photos/reynocum/sets/1804553/