The facts about filters:Â Every good photographer will need some:
There are camera filters for the DSLR camera user that are often forgotten. But, if you talk to a professional photographer, I would say most of them would say there is probably about 4 essential filters you would need in your camera bag to become a serious photographer.  So, let’s go over these filters carefully, so you understand what we are talking about.
Let’s clear up one thing first. There are two kinds of filters. 1- Round filters that just screw on the front of your lens, as you see pictured above, and then 2- the square filters that use an attachment on the front of your lens to add the filter to them.  Let’s look at each style and their needs:
Which type you should choose also depends on the type of filters that you want to use, as some filters are only really useable screwed directly to the lens or in a square filter system.
Skylight filters, for example, are best suited to the round screw-in design, but filters such as neutral density grads are easiest to use in a square filter system.
So, now we have the two different types of filters out of the way, let’s get to the 5 essential filters that I think everyone should own.
#1 – THE SKYLIGHT FILTER
The skylight filter should be a round filter, and should be purchased for every lens that you have. And it’s main purpose is to protect the front element of your lens. I have worked in a retail store before and I have seen the dropped lens brought in many of times. The one with the skylight filter, we just screw off the damaged filter.
The cost to fix the lens: very minimal.  And the photographer is very happy. Now I have also seen the photographer who did not have the skylight filter on his camera, and brings in his lens, and it is broken on the front:
The only thing you can do now is to replace the whole lens. A repair of the lens is out of the question. Usually a repair is much more expensive than a replacement. So, the value of a skylight filter is incredible. JUST DO IT. It is not worth losing a lens over it. And there are good skylight filters out there so you don’t have to worry about the degradation of the quality of your photo. Let me tell you also that there are inexpensive filters and really good, high quality filters, multi-coated lenses used as skylight filters or UV filters. If you spent a good amount of money for your lens, does it make sense to spend $3 for your filter. Come on, choke it up a bit and buy a good high quality piece of glass and don’t degrade the quality of your lens, by buying some cheap piece of plastic lens for the front of your lens.
#2 POLARIZING FILTERS
Polarizing filters reduce the glare off of all surfaces except metallic surfaces. So, water clouds, sky, trees, all have reflective properties. And when you use the polarizing filter, you can enhance the color of those things, because you have cut the glare off those things. And yes, the sky is now going to become a richer blue because of this. This is also best used with a round filter.
The interesting technical feature that most people miss on this filter is that it works at it’s maximum when your lens is at a 90 degree angle to the sun. So, if the sun is straight up, say at 12 noon, the polarizing filter should work great at all horizon shots. But, if you have the sun down close to the horizon, take it at a 90 degree from the sun and you will get a richer color or maximum effect of the filter.
When you get the filter on your lens, it does rotate. Rotate the filter and you can actually see it work. It is amazing and worth every penny. Remember it does not work on metal, so, when you take pictures of your car, it will not cut the reflections off the metal, but it will off the glass.
This is a very visible thing as you rotate the lens. It just pops out at you. The colors become richer, the sky becomes bluer, and the whole scenery is just vibrant. I can’t imagine any landscape photographer not using this.
HERE ARE SOME MORE EXAMPLES OF PHOTOS TAKEN WITHOUT / WITH POLARIZING FILTER:
I think you can see the difference in what a good polarizing filter can do for your pictures. I sometimes get photos submitted to our website of a scenic photo and know that it has not been shot with a polarizing filter. I think: how can I use it? It is just not worthy of submittal.  Please add this to your equipment. It makes so much difference.
#3 NEURTRAL DENSITY FILTER:
A neutral density filter is nothing more than a darkened piece of glass. It does not change the color at all, but, changes the exposure rating of the lens to darker. They will come in ratings of ND 2, 4, 8, which is the value of the light that it cuts in exposure ratings. So, an ND 2, cuts the light by 1/2 and so forth.
Now, the question is what would you use such a filter for?  Let’s throw out a picture and that should explain it all:
The problem you have sometimes, is that the light is too bright to slow your shutter speed down. So, in order to do that, you have to use a filter, like an ND filter to force you camera to think it’s darker out there than it really is. And then you can use a slower shutter speed.Â
# 4 – GRADUATED NEUTRAL DENSITY FILTERS:
The first thing you should notice is that we have switched to the square or rectangular type of filters for this. Can you imagine doing this type of work with a round filter? It doesn’t work very well. How can you guarantee that the dark part will always end up on top or the bottom with the round type filters? Thus, this one has to be square or rectangle.
To use our previous analogy, a graduated neutral density filter, or ND grad, is like a pair of sunglasses with dark glass at the top and clear glass at the bottom.
By placing the dark part of the glass over a sky that’s much brighter than the scenery below, and lining the transition up with the horizon, you can ensure a balanced exposure.
ND grads come in several different strengths, and with different transitions between the dark and clear areas.
For most uses a two-stop grad, also known as a 0.6 or ND4 grad, is a good option, but for shooting sunrises or sunsets with the sun in the frame, you may need an even stronger filter, such as a three-stop (0.9 or ND8) grad, to give a more balanced exposure.
Some of the filter gradations change softly or do it rather abruptly. So, when you purchase them, make sure you get the effect that you want. I usually prefer the soft gradation. That way it seems more natural.
And of course, in this case, the square format filters seems to work the best. The nice thing of course is that one filter will work for many lenses, you will just need to get an adapter if the lenses use different diameter filters on the end.
Here again, the square type filters come in different grades of quality lenses. Please be careful not to degrade the quality of your photo by adding some cheap plastic to the front of your lens. It might be noted as you look for these square type filters that they may come in a package, which I think is great. You may pick up a package of 3 different gradients of density of filters in a nice wallet to carry them in. So, be aware that kind of deal may be the best way to go.
I am not here to push different brands, but the original brand that started the square type filter system was a company by the name of Cokin. They are still around and doing a great job, but, there are many other companies out there now that have sprung up offering quality optical square type filters out there. As well as very cheap ones too.
As you start searching for filters you will discover a whole bunch of different types of filters that you could have fun with. Picture taking with filters is a real fun hobby and at some point I may see if I can get one of the filter companies to let me post a brochure or something so you can see all the different types of filters they make. I will check into that.
Enjoy mastering the use of filters. You will not regret it.
