Digital SLR Photography Tips – Using Photographic Filters
It is always a good idea to have a selection of photographic filters in your camera bag, be it a polarizer, a grad or gradual filter, orange, red or just a skylight/UV filter. You never know when you will come across a situation where you could use a little help in either controlling the light or protecting the front element of your lens.
There are basically 2 “styles” of filter you can have. The normal screw onto the front of your lens type, of which there are many makes some of which are normally more expensive, or the great range from Cokin whereby you have one adaptor attached to the front of your lens and you can replace each square filter as and when required, quickly and easily.
You will need an adaptor ring to go onto your lens, the filter mount slides onto that and clicks into place, and then the square filter slides into that.
I have outlined some of the basic filters below explaining what they do and why you may need them. As there are many, many types of filter on the market, I have kept the list to a minimum of possible daily use filters.
Photographic Filters – No Filter
If you have no filter on your lens then you will get, as best as your camera can record it, the light as the human eye sees it. You also have no protection from the elements such as rain or drizzle, dust or any other airborne particles or fingerprints.
Photographic Filters – Skylight or UV Filter
As you can see from the illustration above, the skylight or UV filter does little to enhance the image, although it can produce warmth in the greenery or colours on the building. What it is actually doing is preventing ultra violet light from hitting the sensor to protect it much in the way your sunglasses do. Most people carry one as a protection for the lens from the elements without affecting the image too much.
You will need different sized filters depending on the thread size on your lens. Obviously, if you have a large range of lenses this can be quite expensive especially if you go for the higher quality filters which I suggest you do. I have just one for each of my more expensive lenses and only use them when I need to.
Photographic Filters – Polarizing Filter
Whilst this is one of my favourite filters, I try and use it sparingly as they can really saturate bright colours. What they will do is eliminate glare and reflections on shiny surfaces such as the sea or a car windscreen. There are 2 types, linear or circular. Linear is really for film but I would suggest circular whatever your medium as adjustments are easier to make.
You attach it to your lens and then, whilst looking through the viewfinder, turn the filter to see it work. If you are photographing the sea for instance, as your turn the filter it is quite amazing to see.
As you can see here, the sea will become transparent and the sky darker because not only are you eliminating the glare from the surface of the sea, but also from the minute particles of water in the air!
Also if you are photographing someone through a window, but have too many reflections, a polarizer will normally lose all the reflections allowing you to see your subject as clear as day (although you may have to move around a bit for the best effect).
This is one filter that I would spend more on as a poor quality polarizer will make your images look poor. I use B + W filters, a bit more expensive but when you spend good money on a lens and you want to add more glass, it has to be good.
They are not always successful as you can see in the example above, no matter how much I twisted and turned the filter, I could only darken half the sky. This was due to the fact that I used the filter on a very wide angle lens. It does’t always improve the image so like I say, I use it sparingly.
Photographic Filters – Grey Grad (or Gray Gradual) Filter
In the situation above with the polarizer where only half the sky was darkened, an excellent alternative is the neutral density or grey gradual filter. These come in differing strengths of gradation and do a great job.
They look something like this and Cokin do a great range from “A” for Amateur to “P” for Professionals (Bigger filters for bigger lenses).
Grey Grad Filter
What a grey grad will do is to just darken the upper, lower, left or right portion of your photograph, depending on which way you have the filter in its holder.
Picture the scene:
You have a beautiful view looking down a big green valley in the spring. The blossom is blooming you have just had rain and everything is as clear and fresh as a daisy. The sky is bright with a few clouds and you want to capture the moment. However, the meter in your camera can’t decide whether to account for the sky or the land. So you either end up with an overexposed and blown out sky with well exposed land, or a perfectly exposed sky and underexposed land.
What do you do? Yes! Put a grey grad filter on. What this will do is darken just the sky enough for the cameras metering to get a more overall correct exposure meaning both the sky and the land will be well exposed. It can make a terrific difference to a picture.
You can see in the image above, the difference between the “no filter” and “grey grad” shot. The grey grad has darkened the sky but kept the building at exactly the same exposure, cool!
As you progress and learn, you will find all sorts of other photographic filters to experiment with but for now, I hope this has given you some ideas to start with.
You can find more info on filters here.