Underexposure + 'Fill Light'
I am following a new shooting method that I read about on dpreview.com forum. The idea is to underexpose the image and then properly expose the shadows in post processing! This method is very useful for scene that have a wide dynamic range such as this photo since there is a large window (lots of highlights), and a lot of dark areas/shadows. Let’s look at this image for example:
If I set the exposure to zero the camera will look at the scene and gives me an over-all properly exposed image. That means, I get some highlights and most shadows—most of the time the window will be overexposed. The problem is that I want to capture more details of the highlights (namely, the window), so what I do is I reduce the exposure by a stop or two using exposure compensation. In this image I reduced the exposure by 2 stops, so what I captured is a well detailed window but very dark shadows (not much details of the dark areas). The idea is that afterwards you open your RAW file in your RAW editor (I use Photoshop CS5 so I will use the names of CS5 options), and increase the ‘Fill Light’ option until you expose the shadows properly (bring out the details in the dark areas); for this photo I increased it to 100% since the shadows were very dark because of the -2 stops.
The bad thing is that doing so increases the noise in the photo so make sure you take the photo at a low ISO, otherwise the noise from the high ISO plus the noise from the ‘Fill Light’ will be too much to handle. Also, if you overdo the shadow fill you will get strange patterns! The good news is: One, most RAW editors can reduce the noise from ‘Fill Light’ wonderfully; I usually set the ‘Noise Reduction’-> ‘Luminance’ to 35% and that should be enough to take care of any noise produced by the ‘Fill Light’ (but remember, I shot this image at ISO 200). Two, since you are underexposing your image—asking the camera for less light—that means you are increasing your shutter speed and so you can use lower ISO without having to worry about a blurry image from hand shake, etc. In this image since I reduced the exposure by 2 stops, that increased my shutter speed by four times. Three, the ‘Fill Light’ only properly exposes the shadows not the highlights so you don’t have to worry about it overexposing the window—the very thing you wanted its details in the first place!
Of course, you can always avoid this method by attempting to recover some highlights by using the ‘Recovery’ option. But for me, for some reason it is easier to fill shadows than recover highlights. I don’t know if it is a general rule that shadows are easier to fill than to recover highlights, or it’s the camera, or it’s CS5 (I doubt it’s the software though!) Anyway, try it if you need to and see if it works for you! Good luck :)
PS: Remember, do not use this method with high ISO! Underexposing the image (for the D700 it's about -2 stops) with high ISO (for the D700 it's around ISO 3200 and depending on the image if there are high contrast areas such as lights) will result in ugly high noise bandings! And sadly, I don't know of a software that can remove those bandings very well.
(Toronto, ON; summer 2011.)