This Instructable demonstrates a cheap, easy solution to applying filters to your photographs as you take them, instead of afterward in post-production programs or tailor-made filters like those found on Instagram.
The beauty of these techniques is that the rest of the many tools a camera allows a photography to use, such as shutter speed, aperture, ISO settings and so forth can be applied to the same photograph, but adjusted as the photo is being taken and as the filter is being applied.
Step 1: What You Need
Your camera. Mine is a Canon Rebel t3i, though any DSLR, point and shoot, or cell phone camera will work.
A set of sunglasses, one with a preferred or unique polarization, color tint or other favorable feature. I've used the technique with a pair of polarized sunglasses I bought in the streets of Chile for $4, and a pair of regular, but dark tinted glasses, both shown here.
Step 2: Applying the Lens
The technique is pretty simple, as you can imagine. Just hold the filter lens up to the lens of your camera and take pictures, adjusting settings and methods for holding the lens as you go. You have to be able to take pictures with one hand, and it gets a little more complicated with a lens that doesn't autofocus, but still doable.
Step 3: Voila!
Here are some examples of photos I took. These are all from Lake Titicaca on the Peru side, where we visited some Island dwelling indigenous peoples.
The last picture is a good example of the same photo as the cover, but without the sunglass filter.