Luvmyzoocrew wrote:
I would love to see your examples.
OK, here they are.
We had a nice day this afternoon, so I went outside with a stack of filters to show the effects different filters had.
First, this is what the scene looked like â just the view down my road from in front of my house:
Hereâs a color picture with a red filter:
Basically, red filter⦠red picture. Not much point, in my opinion.
Red filters are designed for black and white photography. I turned the camera to black-and-white (which I normally wouldnât do, but for the purpose of this demonstration, here we are).
No filter:
Red filter:
As you can see, the red filter darkens the blue sky, and lightens anything red, like some fall leaves.
There are filters which are designed for color use. Iâll demonstrate a few of them here.
Probably the most common filter for color is the Polarizing Filter. Thatâs an interesting one because it doesnât have any color itself, so you donât need to worry about white balance. The filter blocks light which vibrates in one direction, and passes light vibrating in another. So, you have to rotate the filter in its holder to see what effect it has â in one position, it will darken blue skies:
Turn the filter 90 degrees, and the sky is much lighter:
The amount of darkening of the blue sky depends on the direction of the sun. There's almost no darkening in near the sun, maximum darkening at right angles (north, usually, at least here in the northern hemisphere).
Reflections are strongly polarized, so a polarizing filter can also be used to reduce (or even eliminate) reflections off glass or water. Interestingly, you can also use a polarizer to deepen the colors of grass and leaves, since it will block the blue light reflecting from the sky.
Photographers would use âwarmingâ or âcoolingâ color filters with color film. These were very faintly orange or blue, and made a scene correspondingly slightly warmer or cooler. If you used them with a digital camera on auto white balance, the camera would just adjust them away. Thereâs no point in using them with manual white balance, either â just use âautoâ without the filter and adjust the camera for warmer or cooler colors.
Still, there are color filters which can be useful with digital cameras. As Iâd said, if you leave Auto White Balance âonâ on a digital camera, unless a solid color filter is very dark, the camera will just adjust the white balance to eliminate the effect of the filter. So, before taking any of the following pictures I set white balance to âsunlightâ.
âGraduatedâ filters are good examples of filters which can enhance color pictures. A graduated filter is one which is not a solid color, but rather changes in color (or depth of color) from one side of the filter to the other, with a gradual transition area between. All of the graduated filters Iâm showing here were in the Cokin system, which uses square plastic filters. Because the filter is square, you can slide it in the holder to move the graduation point to where you want it in the picture. Round graduated filters exist, but youâre stuck with wherever they put the dividing line.
This is a graduated grey (or graduated neutral density) filter. Itâs clear on the bottom and grey on the top. Itâs useful in holding back a bright sky to allow more exposure for the darker land below (or invert it to hold back bright snow):
I have graduated grey filters in two strengths, depending on how much darkening I need.
A graduated color filter can be used to add color to the sky â hereâs a graduated blue filter (clear on the bottom, blue on the top):
You can turn a graduated blue upside down to add some blue to an expanse of water or snow, too.
This is graduated pink (clear, shading to pink):
Graduated tobacco (clear, shading to brown):
Once you know what that looks like, youâll be surprised how often you can spot the use of a graduated tobacco filter on TV shows.
The âSunsetâ filter is yellow on the bottom, red on the top, and shades continuously through orange in the middle. This probably isnât the best picture to show that off:
This is a better example â the sunset over the Gulf of Mexico was fairly âblahâ, but it became much more interesting with the sunset filter:
Here are a few more examples - I took the same view (the island of Filfla, off the south coast of Malta), without filter, and then with sunset and graduated tobacco filters.
One final example â this filter is not really colored, itâs black. Thatâs right, black â you canât see through it at all. The filter passes only infrared light. Obviously, you canât see through the viewfinder, either, and because most digital cameras have internal filters which block IR, it needs long exposures too. Basically, put the camera on a tripod, aim as best you can, and you never know what youâll get. Live foliage tends to be orange or red, clouds are red, sky is black⦠or not.
One final thought. I said that I donât use the black-and-white setting in the camera. Instead, what I do is take pictures in color and, if I want them in black and white, Iâll convert them in Photoshop. I think that results in a better quality result â and, of course, if you decide the picture looks better in color, youâve got that option.
Hereâs the picture above, converted to black and white using the âblack and whiteâ filter:
I actually think you get a better result (and more control) by using the âchannel mixerâ, which lets you control how much effect each color has on the final black-and-white image. Hereâs the same picture, but I tweaked the levels in the channel mixer:
That allows you to easily simulate the use of a red filter, simply by reducing the level of all of the non-red colors:
Hereâs an actual example, from my trip to Scotland this summer. The picture was taken from the ferry to Islay.
The picture just seemed like a perfect candidate for black-and-white conversion, so I tried it:
Any questions?