Thursday, January 13, 2011

Spice Up your B/W Photography with Filters!

Have you ever tried black and white photography? It´s a great way to express your understanding of shades, shapes and contrast without having to care about stupid colors. But you can use the colors of your subject to spice things up a little or even go completely crazy.


- Add a color filter on the lens (the only way to filter on B/W-Film)
- Add a color filter on the enlarger (when you shoot color negative and expose on B/W paper)
- Use your digital camera´s built-in filter (they "filter" from their RGB pixels, then turn the picture into monochrome)
- Shoot digital color, then use Photoshop for conversion and filtering.
- Convert all the light in your shot to the color of the desired effect (of course, this is nonsense. But it would work the same way!)

Using color filters in B/W changes color and contrast ratios before the (still colored) light reaches the film. The color of the filter enhances light of the same or similar color and reduces light from all contrasting colors. Adding a red filter gives you more density from red colors and less green. Adding a yellow filter gives you more yellow and less blue. And so on. To illustrate this, I shot a Red Habanero (the queen mum of all peppers) against a bed of green parsley, using my 40D´s built-in color filters (click to enlarge):

The green filter turns the red fruit almost black. Red and green add up to a vvery dark hue. The red filter makes it bright and shiny, far too much in fact. Orange and yellow filter work in the same way, but give a much more decent result in this case.
Note how the camera´s filters seem not to affect the parsley at all. Seems that its´ colors are somehow out of range of color filtering (I know this can´t be). Something I have to check some other day.

What about portraits? I used ´shop to filter a color portrait I made to four different kinds of

Note how the blue filter makes a portrait look ill somewhat. The red specks and freckles really stand out. Yuck! The green filter helps the skin in a natural looking way. That´s why it has always been the standard filter for portrait photography. Compare it to the standard B/W conversion of Photoshop. The Red filter, again, overdoes what it´s supposed to do. Sometimes this looks nice, but it almost equalises all the facial features (including the red lips) to a flat, bright surface. You must really want that in order to filter red. A yellow filter does similar things, so does the orange one, therefore I did not picture them here.

Here you can see how mad things get when the colors are vivid! Again, this is Photoshop filtering. See what the blue filter does to the blue egg cup? Likewise, the egg itself behaves like human skin and gets smoothed by red and green filtering and roughened by blue filtering. Green, again, looks pretty much like standard B/W-conversion, so I show you the original image instead.

THE BIG ADVANTAGE OF PHOTOSHOP HERE is, that you can choose predefined filters as well as your own custom colors from the whole palette, change its density and go crazy in every other way, including mixes of hues and colors for filtering. This would mean to the analog photographer, that he´d have to carry at least three densitys of every color filter with diameters fitting every lenses´ mounting ring... oh, wait. I forgot that analog photographers are smart. They know what they want to do before they leave home, then choose their equipment and then go shoot away. I´m sorry! ;-)
Here´s another one from the ´shop. Look how the red filter (replacing a yellow filter that, again, would give a more natural look) helps darken the sky, making it look really interesting:

Back in the old days, film was orthocromatic. It was only sensitive to blue light. You know, the days when you could have a red lamp on in your darkroom all the time. This helped portraits and made nature shots look really, really natural. Today we have panchromatic film, which is sensitive to all of the visible spectrum. Of course, digital sensors also behave that way.

Get yourself a pair of yellow filters. Maybe two densities, maybe two diameters for your favourite lens. This helps skin tones, makes leafs shine bright, brings out nature´s colors and darkens the blue sky a bit, which makes things generally more interesting-looking. Also, this is the way, B/W photography was intended to be made. If your camera meters through the lens, you don´t have to care for anything else. If you use a rangefinder or hand-held meter, look for the filter compensation factor either in the manual that comes with it or on the metal filter ring. It tells you how much light the filter blocks (x2 = 1stop, x4=2 stops etc), then you can auto-compensate for that by changing the ASA/DIN setting on camera or meter (e.g. film is 100ASA/21DIN, filter says "x2" -> set meter to 50ASA/18DIN and it will work together with the filter).

 Today, you can find a set of three fancy filters for some 20 Dollars on ebay. Don´t buy these. They are made from cheap glass or even plastic. Imagine taking out your favourite sharp, contrasty lens and screwing a bad glass in front of it. This deprives the lens of everything you like it for. Really, it doesn´t pay. Save the money for a few rolls of film and go for one of the brand names. Same goes for the UV filters that everybody puts on to "protect" their lenses.

A friend of mine used to carry his camera with a brand UV (or "skylight") filter attached to his lens all the time. While travelling, the camera bag dropped some 80 centimeters from the train seat. Upon arrival, he found that this little impact (in a protective soft camera bag!!) had blown the UV filter to glass dust. Needless to say, he had to throw away the bag, and was barely able to save his lens and camera - he still shakes glass dust out of it sometimes. Protection filter, huh?