A lens and a sensor capturing light are the basic building blocks of creating a digital video. For most consumer applications, this impeccable duo continues to fill the average man with wonder and excitement as he shares and watches his favorite videos. But, for anyone that is even a fledgling photographer, there is more at play in the capturing of this artistic imagery. On some occasions, a picture (or video) just doesn't look quite right through the naked lens, the way that this obstacle is conquered is by the use of filters.
Light filters come in many different colors, sizes, applications, and prices. Below are 5 different types of (physical) filters that can improve the look of a frame in a given situation.
The UV filter
Ultra violet radiation used to be a really big deal with film. It would create a bunch of different weird haze-like effects and cast blueish tones throughout a picture. Today, film is mostly dead to the majority of the population, and UV filters don't seem to be as prevalent among the digital crowd, but that doesn't necessarily lessen the importance of a good UV filter.
The main use of a UV filter, it seems like, is to protect the front lens element from dust and moisture, but UV filters reduce the haziness that even a digital sensor can be plagued with. It is interesting to note, UV filters can exacerbate sun flare problems, and it might be advantageous to use a UV filter in conjunction with a lens hood and a...
A CPL filter, or circular polarizing filter, is one of the most, if not the most, valuable filters that a photographer can have. For an in-depth explanation about how exactly a polarized filter works, navigate here. In short, a polarized filter lets only light pass through it that does not match it's orientation. As per application is concerned, a polarized filter reduces reflected light from shiny things like glass, water, or metal. A CPL can also decrease the amount of light scatter in a scene, giving a photograph a darker more detailed look by taking away the glare reflecting off the highlights of the scene.
Neutral density filters, or ND filters, are also an incredibly valuable asset to a photographer. An ND filter lessens the amount of light traveling to the lens. A photographer might want this for a variety of reasons. One of the biggest is aperture control. There is an inverse relationship between the size of the aperture and the depth of field in a photo, so the larger the aperture (smaller the f/stop number), the shallower the depth of field will be. Obviously the amount of light traveling into the lens will increase as the aperture opens wider, thus brightening the scene. A neutral density filter comes in very handy when shooting in super bright environments where you need a substantial amount of bokeh or a shallower depth of field. The neutral density filter will allow the camera to capture with a larger aperture because less light is getting through the lens.
Another desirable aspect of a neutral density filter is the ability to capture long exposures in broad daylight. Less light hitting the sensor means it will take a longer time for the photo to be exposed properly. If one were to set a super long exposure while looking at a moving object, you would end up with a scene with heavily blurred movement like this:
Taken By: A Wiki Commoner
If you are interested, you should go read the blog I wrote a while back about HDR photography. HDR photos exist because the dynamic range on a typical camera (even really expensive cameras) should be regarded as stupid children toys compared to the human eye. Graduated filters are a way around this problem without having to take multiple exposures. If a scene exceeds the dynamic range of the camera that is being used to capture it, the shadows will be too dark or the highlights will be too bright. A graduated filter is a filter that transitions from clear to an ND filter, the clear half of the filter would go over the shadowy bit of the scene and the ND portion would cover the bight patch. After you adjust your camera accordingly you can get very natural looking shots like this:
Colored filters are tinted a single color to compensate for the color of a scene. The most mind blowing of transformations come from underwater footage. When you go underwater, everything has a very blueish-greensih cast to it and the true colors of things aren't showing. To compensate, a photographer could use a red filter to get a result like this:
The Magic Filters People
Anyway! That's about all I got today, I ate chinese food so I am feeling a bit sleepy...Happy Filming :D!