Lens Filters - Better Photos... Now!

You've probably heard it from almost everyone you've talked to: You'd better put a filter on your lens to protect it. If you're going to spend hundreds, even thousands of dollars on a lens, doesn't it make sense to do everything you can to protect that precious piece of glass? It depends.

The most popular filters to use on a lens are skylight or UV filters. These are both essentially clear filters that, unlike a polarizing or colored filter, don't really affect the properties of the light that enters the lens. The appeal of these filters is that they provide an extra layer of protection between your lens and any dust, dirt or fingerprints that could damage your lens and affect your photos.

Unfortunately, most people (myself included) don't buy a high-quality filter for that expensive lens. Instead, we get decide to save some money and buy the cheap filter. Granted, the cheap filters might only cost $30-$50, while a high-quality filter might cost $200-$300. That's a lot of money to spend on a filter. Compared to a new lens, though, it might be a very good investment.

So why should you spend the money on a good filter? Maybe it's easier to let you know why you shouldn't buy a cheap filter. For the majority of situations you encounter, it won't really matter if you have a cheap filter on your lens. Sure, if you want to get really picky, it might degrade your image quality a bit. Lenses are, after all, built to very strict standards with very high-quality glass and sticking a cheap piece of clear glass in front of a lens isn't going to make your image any better. Ultimately, though, for the average photographer (or client) it's not going change the image quality enough to matter.

There are certain situations where it does matter. For example, when you're shooting a subject and there are defined light sources behind her, you might experience green "ghosts" in your image. When this happens, it's almost impossible to get rid of these after the fact. Making matters worse, it's very difficult to even notice them while you're shooting, so unless you're really scrutinizing your photos as you take them, you might not notice you've ruined your photos until it's too late. High-quality filters are designed so that they don't ghost and will not ruin your photos.

What can you do if you don't want to spend a few hundred dollars on a filter but don't want to risk damage to your lens? First, if you have a lens hood, it should always be on your lens. This will help protect your lens from the majority of bumps you might encounter that could damage your lens (or at least the front element). Second, if you must use a filter, be aware of the kind of situations that could cause problems and remove the filter if you encounter such a situation. It's better to have it on 95% of the time than not at all, right? Some people (myself included) have just decided to go filterless. If you always use a hood and regularly clean your lenses, you shouldn't encounter any issues. Of course, there's always a risk that your lens will be damaged, but that's a risk you have to be willing to take if you decide to not use a filter.

Ultimately, you need to do what makes the most sense to you. Do you regularly take photos of motocross or in the Sahara desert? You'll probably want a little extra protection for your lens. Do the most extreme situations you encounter involve a baby spitting up? You're probably pretty safe shooting without a filter. Of course, you need to decide what your comfort levels and needs are, but with a little thought and common sense, you should be able to reach a compromise between image quality and lens protection.

Here are a few of the images where I first realized how much a cheap filter could ruin a shot.  Keep in mind, I haven't used a filter on my lenses for quite a while, so I had to go pretty far back to find some images that worked as examples.  Also, these aren't necessarily the best shots from this event, just the best examples of ghosting.  :)

Notice the ghosts from the windows on the children.

Again, you can see the window's ghost on the guy's arm.

This is a very bad ghost.  It's coming from the door behind the crowd.
You can actually see the trees that were outside!

For more on this subject, hop on over to this excellent article by Thom Hogan.

Read all of my DSLR tips here.