I know the title of this post must sound a little odd, but I promise that it will all make sense in the end. First, let’s talk about gray scale vs black & white images. If you talk to any photographer they will always use the term “black and white”. If you talk to a designer, they will usually refer to these same images as “gray scale” [or if you're British, "grey scale"] images. So what’s the difference between the two? Actually, there is no difference. OK, so far I haven’t really helped to clear anything up – BUT – what I want to accomplish here is to have you think in terms of “gray scale” whenever you want to end up with a black and white image.
Before I go on any more about “gray scale” let’s talk about the options you have available for creating black & white images. First, a lot of digital cameras these days have presets that allow you to capture any picture as a black & white image. While it seems an easy way to go if you want black & white images – there are some significant problems with doing this. The first, and most obvious, is if you shoot in “black & white mode” you lose all the original color informtion. It’s discarded and there’s no way to get it back. That’s a big loss if you’re thinking in “gray scale” for doing your color conversions. It’s also important to keep the color information since I often render an image in both color and black & white. The other problem inherent with this is that the camera does all the interpreting of what makes a good black & white image – not you!
Now, some newer cameras offer a potential way around this dilema of shooting color or black & white. They can create large, RAW color files and also a smaller black & white jpg file at the same time. While this is handy, it takes up more space on your card, therefore less images. This can be a big drawback – especially if you’re traveling. Also, just like I said earlier, we’re back to the old problem that the camera is creating the black & white file, not you. It can give you an indication of what the file looks like in black & white – but so what? It probably won’t look like the final image anyway. You need to determine that when you’re doing your editing.
Everything I’ve said so far has been to, hopefully, convince you to do all your shooting in color. Now comes the reason why you should be thinking in “gray scale” in lieu of “black & white”. When you’re editing your images you need to keep in mind that every color has a value that can be interpreted as a shade of gray – hence “gray scale”. Not only that, but any color can be interpreted in many shades of gray – from white to black! Sounds crazy, but it’s true. By using your editing software to interpret each color’s value into a specific shade of grey you can significantly alter the final image and make it look just like you want it – not the camera’s interpretation of what it thinks looks good. Let me show you a few examples. Below are a series of gray scale images made from one color image. While it looks as if I’ve changed the brightness or contrast in several – the only change has been to adjust the percent of a single, specific color – changing its value – or the shade of gray if you will. If you have Photoshop CS 3, 4 or 5 or Photoshop Elements 7, 8 or 9, it’s as simple as moving a slider to the right or left to make the changes. In each of those software applications – after the black & white auto-conversion is made – they allow you to make adjustments by “tweaking” the value of each color by moving those sliders.
So, let’s look at what a difference these “tweaks” make to the image. The first gray scale image [under the color one] shows an automatic B&W conversion, letting the software do it for you. It does an OK job – though you’ll note that it’s sort of flat, with not a lot of contrast. The next converson shows where the color yellow has been adjusted. Because the flowers are predominantly yellow – by increasing the percent of yellow it makes them brighter, almost white. A similar effect is shown when the green percent is increased. Note that the mans’ green sweatshirt becomes lighter – setting it apart from the background.
The next conversion shows what happens when just the red is adjusted. The differences here are a little more subtle. You’ll see the differences in two areas. First, look at the mans face and hand. Because there is a bit of red in his skin, it becomes brighter by moving the red color slider to the right and increasing the amount. If you look closely, you’ll also notice that the red coat on the woman in the background has also become lighter.
The most significant change took place when the blue and cyan are both reduced in percentage [moving the slider to the left] which darkens them and creates a much more contrasty image. Now the man and the flowers really stand out from the background.
The last image on the far right shows when all the changes are applied to the B&W auto conversion. Is it better? I think so. The flowers have been emphasized. The man stands out because his skin has a lighter value and his sweatshirt is now a more distinct value from the flowers. Of course the dark background now makes the picture pop.
So there you have it. All of the above was to show you why it’s so important to save your color data and use it to make your black and white – or if you prefer – gray scale images. I hope you’ll give this a try and play around with the many options you’ll see as you move the various sliders. Your final image will probably look different than the one I might create – but it will be all yours. Best – Bill