Fun with Filters

A filter is a piece of glass that fits onto the front of a lens to protect it or create special effects. SLR cameras (that allow lens changes) and some fixed lens cameras, have threads on the front of the lens that enable you to screw a filter on. A few fixed lens digital cameras (such as the Canon A95, Fuji S3000, and Konica Minolta Z series) have threads on the body of the camera that enable the addition of a hood. The hood goes over the lens and allows the lens to fully extend without hitting the filter (or additional lens) that is screwed on to the hood. Sorry this is hard to explain and understand if you haven't seen how these things work. Basically an SLR filter fits on the lens itself so if the lens goes in and out the filter goes with it. The hood system is for fixed lenses that don't have threads on the lens itself, thus the hood has to extend beyond the farthest extension of the lens. Finally there are digital filters that are simply effects selected in a menu on the camera. If you are still confused as to what filters are, visit your local camera store and ask them to show you.

So what kind of filters do you need? If your camera is capable of using filters, I recommend having a UV filter for every lens you own. The UV filter can be left on the lens all the time and it's most important function is protecting the lens. If you get a scratch or a ding on the UV filter you only have to spend $20 - $40 bucks to replace the filter, but a lens could cost hundreds or thousands.

I also have a polarizing filter for every lens I own. The polarizer works like sunglasses to reduce glare on water and glass. If you take a picture of a car without a polarizer, you probably won't see the people inside, just glare on the glass. With the polarizer you will see the people inside the car. Polarizers are also especially effective for pictures with water in them. On a sunny day water reflects a lot of light and the polarizer cuts down the glare. If you have autofocus lenses, be sure to get a circular polarizer. Linear polarizers can confuse your camera's autofocus.

Now the fun part: Special effects filters can be a lot of fun. I've met lots of photographers who snub filters wanting to only produce pictures that capture the true image. Take the shackles off and have some fun once in a while.

The most common special effect filter is the cross screen filter, also known as the star filter. Star filters most commonly come in 4 points. You can get 6 and 8 point stars though. This filter streams light from a bright light source creating a star effect. The picture of the old courthouse with the sun setting in the window is an example of the star filter.

All of the filters discussed so far are round filters that can screw directly onto your lens. The next group of filters I'll talk about are square Cokin filters. Cokin makes both round and square filters, but they are best known for their square filters. How can you screw on a square filter? With a Cokin filter bracket. A round adapter screws onto the lens and the square bracket then mounts on the adapter. Square filters are useful when you want an effect that only fills half of the lens. Such as a sunset filter. The sunset filter enhances the sky colors while leaving the foreground with no or less effect. If this were a round filter you'd run into problems if the filter horizon didn't align with the true horizon. Thus they are square.

Another square Cokin filter is the speed filter. It is half clear (no glass) and half thick, arched glass. It allows part of the pic to look normal while the other half is blurred, creating a speed effect. The bulbs with the light emitting from the side were taken with the speed filter.

I do have a couple of great round Cokin filters. One is called the radial zoom. This one can be used to give a blur effect to the outside of the pic, closing in on a clear center. The pic of the two flame bulbs in the circle of light shows how the radial zoom can be used with lights. Note that the effect is drastically different as you zoom closer or farther out.

The other round Cokin filter I have is called the Cosmos. WOW this filter creates straight rainbow colors of light at the angle you choose. Similar to a prism effect. The jeep headlight was taken in bright sunlight with the Cosmos filter. I saw a picture on CNN this week that had three nuns in white with a prism of color light streaming behind them. I'm pretty sure this effect was created with the Cosmos filter, or one similar to it.

There are hundreds of filters available, the trick is finding the ones you need. Cokin filters come in an A series for smaller lenses and the P series for lenses with an objective larger than 58mm. Tip: To find out your lens filter size look inside your lens cap. Common filters such as UV, Polarizers, and cross screen filters are not that hard to find. Special effects filters may have to be ordered if they aren't in stock, and my experience has been that the vendors are incredibly slow to deliver on special orders. So if you have to order something special be sure to order it 2 months before you need it.

As for all those anti-filter folks, to each his own. Sure sometimes you want something close to reality, but sometimes it is a blast to have fun with filters.

geopic