Let's start with image acquisition -- film first. You can go back and re-read
Lesson 2 Chapter 2 as needed. When scanning b&w film you want to remember that
grayscale photos require only one third the disk storage space that color
photos require. Color photos are 24 bit while grayscale photos are 8 bit.
There's nothing otherwise special about scanning b&W film except this: I've
used a lot of different scanners over the years and I've often found that I can
get a better scan from b&w film by setting the scanner to color negative. It's
not a big deal, because you can always adjust the scanner's tone response up
front, but I've often found setting the scanner to color negative gets me a
better scan faster. Mouse over the image above to see what I mean. The
greyscale image is my scanner's "auto" attempt at a somewhat touchy high
contrast b&w negative. The brown tinted image is what I got from the same
scanner by simply switching the scan mode to color negative. Notice how much
better the scanner did with the highlight detail in the coleus leaves. Once the
image was in Photoshop it was a simple matter to convert it to grayscale and
finish any necessary adjustments. The image is a link -- click on it to see my
final version of this photo.
Better B&W through Color
If your digital camera has a special feature that allows you to take b&w photos DO'NT USE IT! To get the best results in black and white start with a color original. Even if you're working with film, shoot color film to get better black and white photos. Now that last statement is going to upset some people so I better explain precisely what I mean.
I've been a professional photographer and/or photography teacher for 30 odd years now. When I started in the photo business a computer filled a small room and the people who used it all wore white lab coats and carried clip boards (and the computer worked). I've lived through photography's switch from analog to digital tools. For the most part I work now with a digital camera, a computer and a digital printer. I rarely work in the wet darkroom and I rarely shoot film. I didn't make the switch to digital because I like computers (I don't like computers). I didn't switch because I don't like the darkroom (I don't like the darkroom). I switched when it was obvious to me I could get better photos. I'll use whatever tools will get me the best result. Now in photography "best result" is relative to circumstance. It can depend a lot on what type of photography you're doing, eg. fine art, commercial, industrial, etc.
In the field of fine art b&w photography film and the wet darkroom are still critically important. Digitally processed b&w photos are equally as good as those made in the darkroom when we compare image characteristics. However they do not have the same physical appearance which is important to many fine artists. And, most importantly, digitally printed b&w photos will not last as long as those made in the darkroom. This factor tips the scale in favor of the wet darkroom if you're working as a fine art photographer. There is no way that the inks in a digital print are going to resist fading like a properly processed and toned silver print.
| Calvin: | Dad, how come old photographs are always black and white? Didn't they have color film back then? |
| Dad: | Sure they did. In fact, those old photographs are in color. It's just the world was black and white then. |
| Calvin: | Really? |
| Dad: | Yep. The world didn't turn color until sometime in the 1930s, and it was pretty grainy color for a while, too. |
| Calvin: | That's really weird. |
| Dad: | Well, truth is stranger than fiction. |
| Calvin: | But then why are old paintings in color?! If their world was black and white, wouldn't artists have painted it that way? |
| Dad: | Not necessarily. A lot of great artists were insane. |
| Calvin: | But... but how could they have painted in color anyway? Wouldn't their paints have been shades of gray back then? |
| Dad: | Of course, but they turned colors like everything else did in the '30s. |
| Calvin: | So why didn't old black and white photos turn color too? |
| Dad: | Because they were color pictures of black and white, remember? |
| --Bill Watterson |
The photo below, a rose from my wife's garden, is a perfect example. The rose separates from the leafy green background because it's red which is the complement of green -- color contrast. Mouse over the image and you'll see how it would have photographed in b&w. It's much weaker as the red of the rose petals transforms into shades of grey that are similar to the green foliage.
The red and green both had similar luminance levels. The image is a link. Click on it to see how the same scene would have photographed in b&w through a red filter. The red filter over the camera lens lightens the rose while at the same time darkening the leaves. The result is much more faithful to the feeling of the original color scene, and a much better photograph.
Finally we get to the punch. Photoshop can convert any color photo to b&w and while doing so simulate the effect of any colored filter over the camera lens. In fact Photoshop can do this selectively to individual parts of the photo. An orange or even red filter will darken a blue sky and make the clouds stand out. A green filter will ligthten dark foliage. With a film camera you could choose one or the other, with Photoshop you can have both.
Your image must be in RGB color mode. Very simply Photoshop allows you to blend the three channels (RGB) unequally. From the Image menu select Adjustments, Channel Mixer. Check the box labeled Monochrome in the lower left corner of the Channel Mixer control. Adjust the value for each channel so that the total is close to 100. For example Red = 60, Green = 20, Blue = 20. If you adjust the mix so that the total exceeds 100 you can lower the value for Constant. If the mix is heavy on the red channel it's just like you took the picture through a red filter -- heavy on the green channel and it's like you used a green filter on the camera.
To apply more than one channel mix to separate parts of a photo simply make a selection first. The Channel Mixer will only effect the selected area. Then invert the selection and apply a different mix on the rest of the image.
One more for fun. The photo to the left was just begging me to use it as an example. The bricks are red and the trim around the windows and door is green. Mouse over the photo and you'll first see the result produced by Photoshop's Desaturate menu option (located under Image, Adjustments). It's typical of an unfiltered b&w photo using film. Now mouse over the two window signs that say Amighetti's Bakery, first the left then the right. You tell me how I filtered them. Which rendition is most faithful to the original color photo?