The power of black & white

About two weeks ago, during a day off, we were having a late breakfast at the terrace of a cafe situated at the Tachinger See (a quite beautiful spot with good food, coffee and cakes;-) - I had the camera with me because we wanted to continue into the mountains that day, but it was very very hazy, low contrast, lots of light blue. The trees at the shoreline were reflecting quite beautifully in the lake so I made a couple of photos.

Here's one of them (and say, isn't it lovely?). I converted the picture into some sort of high-key black and white, and that was one "WOW!" moment for me, I could hardly believe my eyes! Some details in the sky got lost in the process, but nothing of importance to the scene. I increased the shadow contrast a little bit by adjusting the black point, and that was all.

What I'm trying to say is... whenever a picture is color-wise boring, or color doesn't really help the picture at all, before throwing the picture away, try a black & white conversion. If you do it with Picasa, use the "Filtered B&W" effect, not the normal one! You'll be offered a set of pre-defined colours - try red & green before anything else, these two colors differ so much, you'll be surprised. The red channel is often very unstable and produces a lot of noise, the green channel however gives very even pictures (this is typical for digital cameras - of the four pixels in the Bayer pattern, two are green, and only one blue and one red).

Picasa Tuning Functions explained

If you've been using other photo editing software, you surely recognized the functions that Picasa offers on the "Tuning" (german: Feinabstimmung) tab when you're in edit mode. Here's an explanation, because IMHO there are rather important functions, and its good to know how they work:

• Fill Light (german: Aufhellen - a very problematic translation IMHO): makes the dark parts of the picture brighter, but doesn't change the brightest parts of the picture (the white point stays the same - more on that below). Use it to recover details of things drowned in shadows (most often, there's more information in the dark parts of a picture than one would expect). Moving this slider to the right reduces the contrast of the picture.
  
• Highlights (exactly the same in german... a fitting translation would be "Helle Bereiche" maybe): makes the bright parts of a picture even brighter. Notice that you can't make bright parts darker, only brighter - and here's why (if you're familiar with a tone curve editor you may have already guessed it): this is the white point adjustment. The further this slider is moved to the right, the earlier "white" starts in the tonal range, and quite obviously you can't make white any "less white". We could say that this slider, when moved to the right, makes things white that originally were not all white (don't overdo it!) Together with the third slider, you can increase the contrast of your pictures:
• Shadows (german: Schatten): makes the dark parts of the picture even darker. Use it to increase contrast together with the Highlights slider. Again, if you're familiar with a tone curve editor, this is the black point adjustment. The further you move this slider to the right, the "earlier" (or later, depending on which direction you look at it), the more the dark parts of the picture will be pronounced (because they're made darker). And you guessed it: the opposite of this slider is the first one, Fill Light!

If you play with these sliders, open the "Histogram & Camera Information" infobox (with the "propeller-equipped colorful cap" button on the bottom-left side of the edit mode window) and look how the distribution of tonal values changes when you move the sliders.

You surely have noticed something now. We can increase and decrease the dark parts of the picture, but we can only increase the bright parts of the picture. Picasa has no exposure compensation slider that would allow it to increase and decrease the total brightness of the picture. This is problematic for scenes in bad lighting, because cameras aim at an average exposure, making (relatively) dark scenes too bright.

There's a (limited) way to reduce the brightness of a picture with Picasa, though. You can use the "Graduated Tint" (german: Farbverlauf) effect for that. It doesn't replace a real exposure compensation slider, but its better than nothing. Here's how: in edit mode, go to the "Effects" tab and select "Graduated Tint" (now, who would've guessed that...). As explained in an earlier post (where I described how to fix too bright skies with that effect), if you do not select any color, the tint will be neutral grey. Move the handle in the picture all the way down to the bottom of your picture (you can immediately see how it gets a bit darker). Move the "Feather" (german: "Übergang") slider all the way to the left so that the feather is no feather, but a straight line. Now you can adjust the amount of "darkening" with the "Shade" (german: Schattierung) slider.

And there's a fourth slider (color temperature) and an additional control (neutral color picker) on this tab, but I guess these two functions are pretty self explanatory. The neutral color picker has been explained in the Google Photo blog recently.

6500K

This might be a very simple hint, but its very important. Maybe I didn't search hard enough, but I only stumbled across this accidentally (a while ago when I started to approach digital photography with more caution), so I thought I'd share the knowledge.

6500K is a color temperature. Its not any color temperature, but its the white point in the sRGB color space. Which means: at 6500K, white is white. Completely neutral white. White as white can be. The dream of all toothpaste marketers. This is important if you want to judge the color temperature (white balance) on screen, because it is very very likely that your camera uses that sRGB color profile (at least if you did not re-configure it manually to use AdobeRGB - which is not a problem btw. because AdobeRGB has the same white point).

Now, not everyone (yep - that includes me) has a hardware calibration tool for the screen (and yes, I wonder: why is that crappy gadget so darn expensive?!*). Perhaps its not really a problem for amateurs, anyway. But!!! A lot of monitors are set to a very cold color temperature by default (the default "Normal" of my Samsung LCD is above 9000K, for example), so what you really must do to get a better impression of your photos is to set your monitor's color temperature as close as possible to 6500K (laptop displays are a real problem here - ever saw one that allows you to adjust the color temperature at all? Let me know, I'm interested).

A little bit of background information. 6500K is warmer than 9000K? How's that, since 9000K is a higher temperature than 6500K? Well, yes, but this is about color, not about heat. The whole idea of calling it color "temperature" is based on the "Black Body Radiation" model. I'll try a simple description.

You heat up a very very very black stone. As you increase temperature, it starts to glow deep deep red. You increase the temperature further, and it starts to glow bright red, orange, eventually white. You still increase the temperature, and it turns from white to blue. Like the hottest part of a candle flame - its right in the middle, and its blue. The cooler parts of the flame are on the outside. Now, it happens that we humans associate red and orange tones with "warm", and blueish tones with "cool", so a higher color temperature is actually a colder color.

*a lot of time has passed since I wrote this. Get a hardware calibration tool, its the best you can do. Read the posts with the calibration label for an explanation.

Shoot Raw!

I've been converted to using converters, to say so. Raw converters, to be more precise. Here's the story, it should serve as a first explanation for my plea - "shoot raw!".

In a german bulletin board (that focuses on Nikon cameras, but it doesn't really matter), one of the usual newbie questions is, what good is shooting raw instead of JPEG. And back then, being a newbie myself (and a believer in, erm... more of the things that Ken Rockwell says than I am now!), I was all for JPEG because the hassle of shooting raw and developing the files myself bothered me. I switched my camera to raw mode for a day and then tried what I could achieve. I found it quite irritating, all these sliders and things, highlights, shadow contrast, tone curves, hue, white balance tone adjustment... I decided this was not for me and returned to JPEG.

However, it didn't take long to discover that JPEG with its 8-bit depth is rather limited, and I do believe now that a great many of the sophisticated amateur photographers out there will make the same discovery. Overexposed, burned out white where a blue sky was on a sunny day, or shadows drowned in black - does that sound familiar? If you're shooting landscapes, it sure does...

Someone in that Nikon bulletin board (a rather edgy person, I must admit...) said that he wished that newbie's (like me...) wouldn't take the pro-JPEG position so easily (like I did...). At first I was offended, but then he explained that he wished he had the photos of his JPEG "era" in raw format. This gave me food for thought, and guess what... I wish I had my first stack of photos as raw files now instead of JPEGs. :-P

So. If you're new to photography and just bought that wonderful DSLR, no matter which brand it is, do yourself the favour and shoot raw from day one on. If you're not interested now, let the files run through the batch converter that usually ships with every camera brand and use the JPEGs. But keep the raw files! Storage space is so cheap nowadays, it shouldn't matter.

When I find the time I'll go into detail and post some examples. The good thing about my Nikon camera is that it includes a fullsize JPEG into the raw image. This JPEG file can be extracted and then used as a comparison - self-developped raw files vs. camera-developped JPEG. You'll be surprised.

More about shooting raw can be found when you browse the "raw" label of my blog. Very important information regarding picture control on the camera's diplays is here.