Introduction: Super Cheap, Super Easy Solar Filter for Your Camera
Build a cheap and quick solar filter for your camera to allow pictures of the sun. NEVER LOOK DIRECTLY AT THE SUN WITHOUT A SOLAR FILTER. THIS IS ESPECIALLY TRUE WITH ANY MAGNIFICATION (ask the ants under the lens in the cruel kid's back yard how that worked out for them).
On August 21, 2017 there will be a total solar eclipse that will be visible from many parts in the continental U.S. (and the partial eclipse will be visible from Hawaii, Alaska and much of Canada). You don't want to miss out on this, right? But you don't have a zillion dollars to spend on equipment to view it. This project will get you the quick and dirty. It won't be ultra high quality, but for the price (and the time devoted), you should be pretty happy with the results.
Step 1: Gather Supplies
You will need:
1) A pair of cardboard Solar Eclipse glasses - google it. Your local astronomy club will probably have some.
2) A cheap lens cap - if you shop around, you can find it for about $7, but even at the full-service photo place, they aren't outrageous.
3) Office supplies: Scissors, tape.
Step 2: Cut the Glasses
Cut one of the lenses from the solar eclipse glasses out. Cut it leaving a decent amount of cardboard so you can handle it and tape it. The overall size should be smaller than your cap (see image from later slides).
Step 3: Drill a Hole in Your Cheap-o Lens Cap
Look at where the latch mechanism is on the cap; don't want to drill on a moving part. Try to get pretty close to the center, but I suspect there is little difference and you may even get a little less glare going slightly off center (in my case, I didn't do a great drill job). Be sure and use safety glasses and DO NOT HOLD THE CAP WITH YOUR HANDS WHILE DRILLING. At a minimum, use pliers. You can start with a pilot hole like I should have and work your way up. I ended up with a quarter inch, but you might want to go larger.
Step 4: Assemble
Tape your cut out solar glasses to the back of the lens cap. I went with cheap tape, you might want to use black electrical tape just in case you end up with a light leak. Don't tape where the hole is..even if you use clear tape; it may distort. When you are done, you don't want it to fall off (see the two warnings in here about going blind from the sun).
Step 5: Test Without Using the Sun - Look for Light Leaks
You can test it by pointing a cell phone light towards the cap (with or without a camera). If you cracked the lens cap or scratched the solar eclipse glasses, you should see it. The point being that you don't want to find out the hard way that you are pointing your telephoto lens to the unfiltered sun while looking at the sun. Repeated warning: NEVER LOOK DIRECTLY AT THE SUN WITHOUT A SOLAR FILTER. THIS IS ESPECIALLY TRUE WITH ANY MAGNIFICATION (ask the ants under the lens in the cruel kid's back yard how that worked out for them).
Step 6: Take a Test Shot of the Sun
If you have an SLR camera with a digital viewfinder and a visual viewfinder, use the digital one. If you screw up a camera, that sucks, if you go blind, that sucks more. I started out with pretty high speeds (1/500th) and worked my way down. I suspect the exposure depends on the hole size to some extent. This was taken at 1/40th of a second at f5.6 / ISO 640. Your mileage may vary.
For more information about the eclipse, google it and/or go to