Hours of Idleness-A Photographer's Journey in St. Louis

Filters

Posted in 35mm, art, photography, technique by Jason Gray on July 24, 2010

“The ability to simply render the world is not the job of the artist today. None of those who call themselves ‘realists’ can do what a camera can do. No way. What an artist must do is see something else-something the camera cannot see. That is not something you do with your eyes only.” -Leon Golub

Although Mr. Golub was speaking figuratively, his statement might as well be an endorsement for filters if taken literally. Filters are one of the few tricks up the photographer’s sleeve that enable him/her to manipulate a recording of the obvious, and are one of an even smaller bag of tricks available before the exposure is made. A filter is a disc or sheet of colored or tinted gelatin, plastic, or glass fitted into either a square holder in front of the lens or in a circular holder that screws onto the front of a lens. In some cases, filters can be used over the light sources instead, but that moves into the terrain of lighting modifiers, which will be covered in the article on lighting equipment.

Generally, filters screen out haze and glare or increase tonal contrast; almost all filters reduce the amount of light entering the lens. In terms of popular use, there are five main groups of filters:

1. Ultraviolet (UV) Filter- reduces haze; useful for photographing subjects at a distance and high-altitude photography. Because UV Filters stop very little light from entering the lens, they are commonly left screwed onto the front of the lens in all circumstances as a first defense against blows to the front element. I don’t recommend this simply because there is a coating applied to these filters that does slightly effect the results of your images, and if you are spending a lot of money on your lenses with optimum performance in mind, why take steps to impair them? This is especially true since another filter is manufactured solely for the purpose of defense, and is a better option, as we will see. In modern DSLR cameras, the digital sensor already has a UV coating applied to a pass in front of it, so there is little practical need for these filters unless you are commonly shooting in extremely hazy conditions at high-altitudes.

Example (Quantaray UV Filter mounted onto a Nikon Lens):

2.Polarizing Filter- screens out glare from reflective surfaces and increases saturation in foliage and sky; useful for photographing water surfaces (ie. reduces the amount of glare reflected back from the water), landscapes on an overcast day, or reflective objects (non-metallic) in commercial photography. A circular polarizer is preferred over a linear one because the latter negates your camera’s through-the-lens metering function. Of all the filters commonly used in film photography, the polarizer may be the single one most viable to digital shooters as well. Although most of the saturation benefits can be compensated for within the DSLR’s menu controls, the polarizer’s function of reducing glare is still exclusive to this filter.

Example (not mine; from here):

3. Color Filters- increase/decrease tonal contrast in black-and-white photography and can be used to add “warmth” or “cool” to a shot. In black-and-white photography: A yellow color filter adds a very low level of additional contrast, and it causes a slight darkening of sky and a lightening of anything yellow. An orange color filter increases contrast a bit more than a yellow one, and causes the sky to stand out even more against the clouds; all orange elements will be registered as a light gray. A red filter really pumps up the contrast, drastically darkening the sky against the clouds, while objects that are red will register as slightly lighter than they normally would. A green color filter lightens the sky slightly and lightens any areas of green, but additionally, the green filter has a very pleasing effect on skin tones, as it softens them and makes them more even. However, this softening affect is achieved due to a reduction in contrast, which can be detrimental to other subjects or compositions. As primarily a digital photographer, I do not even own color filters. This is because I do black-and-white conversion in post-processing, and can apply all of these filter effects there. In addition, if I really want to produce b/w straight out of the camera, I can select the monochrome, jpg, picture control mode, and apply these filter effects in camera through the menus.

Example (not mine):

4. Neutral Density (ND) Filterreduces the overall exposure or parts of the exposure (in a graduated ND filter) by screening the amount of light entering the lens; useful for extending your shutter speed and/or enabling wider apertures in bright light. Common uses for this filter are the shots that you see of waterfalls or streams blurred into a long creamy ribbon, which are the result of using a slower shutter speed. By reducing the light entering the lens, the filter enables the photographer to experiment with motion blur during the daytime. In some of these running water shots, a polarizer is added to the neutral density filter to both saturate the surrounding foliage and reduce the glare of light reflecting off of the water’s surface. Another use for these filters are for outdoor portraits, such as at weddings, when your goal may be to use a wider aperture in order to throw your background out of focus. For landscape photographers, there is often the problem of balancing the dichotomous exposure values between the sky and the earth/sea, which can often be stops apart. In this case, a graduated neutral density filter (that blocks a lot of light at the top of the filter, where the sky is at its brightest, and slowly graduates to allowing in more light until the most light passes through at the bottom, where the foreground is at its darkest) can be useful. Like the polarizer, the neutral density filter still retains an important position in the digital photographer’s camera bag. Although there are adjustments that can be made in Photoshop and other editing software to account for some of what these filters do.

Example (not mine; from here):

5. Neutral Clear (NC) Filters- are simply used to protect the front element of your lenses. These filters have no light-reducing capabilities, and serve no function except to act as a buffer between your lens and the outside world. There is some argument as to whether or not they should be used, and the two biggest detracting points are: 1. They are a waste of money because they don’t do anything (I don’t believe so. Since they are relatively inexpensive compared to the cost of fixing/replacing a lens, I’d much rather be insured than sorry. I have one of these on every single lens that I own.); 2. Slapping a cheap piece of glass on front of a high-performance lens system that you paid big money for is asinine (There is more truth in this statement than the last one, I’ll admit. I don’t like the idea of putting something in front of my lens that will detract from its performance, which is why I buy only my camera manufacturer’s NC filters (there are other good ones, but I’ve tested the Nikon ones by using them everyday for years). I personally don’t believe that these filters, the Nikon ones, detract enough from my picture quality to justify me exposing my lenses to the destructive whimsy of chance. You may be different, but that is for you to decide. However, I would recommend that if you are planning to use one of the other filters for a particular shot, that you remove the NC filter beforehand, as opposed to stacking them. I just don’t see the need to keep it on under that circumstance.

Example (Nikon NC Filter mounted on Nikon Lens):

If you are deciding what filters you might like to use and are looking from recommendations on brands, I only have experience with a small hand-full. On the cheap end, the Optekas, Tiffens, Sunpaks, and Quantarays are generally about what you might imagine; you get what you pay for (sometimes they are not even glass). However, the significant increase in cost between them and the Nikon ones that I have defaulted to using is not necessarily relative to an equally significant increase in performance. The Nikon ones are good though, and they are reliable and sturdy, so I continue to spend the money on them. There are other good brands though, like Hoya, B+W, etc. Whatever you decide to buy, and whatever factors decide that for you (performance/price/availability), don’t let anything stand in the way of having fun and experimenting.

“As war is not won by brilliant retreats, so creativeness is not advanced by imposed limitations.”Fairfield Porter

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  1. […] Cameras 2. Film 3. Lighting Equipment (coming soon) 4. Filters 5. Lenses (coming soon) Tagged with: Basic of Photographic Equipment, Jason […]


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