May 14, 2005

This is a continuation of my letter to Annia, who wanted to know about Tudography. Today I’m discussing editing techniques, and yesterday I told her how I take pictures. This is a beginner’s guide — add your wisdom in the comments.

Dear Annia,

Most photos will look great if you think about what you are doing before pressing the shutter button. However, depending on the light conditions, some shots will come out looking dull and uninspiring. They won’t capture any of the vibrant colours and shapes you saw with your own eyes.

This entry will hopefully give you some ideas on how to improve those pictures. Before you begin, sort through your images and discard as many as possible. Be critical — a bad shot is a bad shot. Once you have a handful of images that have potential, open them in a graphics program like Photoshop.

The goal is to improve the photos without making them look unrealistic — we want our photos to match the colours we saw in real life. The more you tinker with your images, the quicker you’ll be able to identify what needs to be improved — so experiment with any and all of the following adjustments:

1. Crop your picture. Make sure the main elements stand out and that the composition makes sense. Often you want to move subjects away from the centre and rebalance the image. In the image below, I cropped out much of the dead space around the principal characters. This allows the viewers to focus on what matters.

   

2. Adjust levels. When shooting in unfavourable light conditions, the camera’s sensors will often record ultraviolet noise. The resulting photos will seem dull, and the corresponding histograms will show a flat line at the end of the data interval:

   

   By adjusting the levels in Photoshop (click Image -> Adjustments -> Levels), we can eliminate much of this dead space in the colour spectrum and make our images more vibrant. Just slide the left and right pointers so there are no more gaps at the end of your histogram — and slide the middle knob too to balance things out. Below, I’ve adjusted the levels in the dummy hand picture, significantly improving the image. You may also want to give Photoshop’s Auto Levels a try, though it often butchers decent images.

   

3. Adjust colours. Photos sometimes have an unintentional colour tinge to them, which can make them unpleasant. In Photoshop you can correct this by adjusting the colour balance (go to Image -> Adjustments -> Colour Balance). The original image shown below had a cyan tinge, which we removed by adding more red to the image. The resulting image has slight red tinge which is somewhat interesting.

   

Photoshop also lets you adjust variations, which makes it easier to correct colour discrepancies. In other programs, you can adjust the levels of the individual colour channels to obtain a similar effect.

4. Adjust contrast. You can make some images more vibrant by adjusting their contrast. Because the original image below was a little dull, I significantly increased the contrast to bring out the colours in this rusted door. Often, adjusting the curves instead of the contrast will give you more control over the result (by using curves you can, for example, make the light pixels lighter and the dark pixels darker to give you a nicer contrast).

   

5. Adjust hues and saturation. You can add extra saturation to your photos to make the colours richer. It is easy, however, to make them look unnatural. Restraint is key (something I have little of).

6. Sharpen your image. By sharpening your image you won’t be able to make an out-of-focus shot look any better. However, you can get more detail out of your shots especially after the images have been shrunk.

1. Handle the skies. On sunny days, you’ll often capture images that have a blindingly bright and washed-out sky and a dark object in the foreground. The sky in the original image below looks nearly green. Photographers often fix this problem by applying a polarizing filter, but you can also use Photoshop to improve shots already made.

   

   The key is to consider the sky and the foreground as two separate images. Select the sky as one unit using the Magic Wand (with a high tolerance). Then, adjust the levels and brightness of the sky. Once you’re satisfied, select the inverse and repeat the process. I went apeshit with the adjustments in the photo above to get the point across, and the photo looks artificial. You’ll rarely have to go that far with your improvements.

2. Remove noise. When shooting dark scenes there may be a significant amount of noise in your pictures. You can fix this with Photoshop’s “Dust and Scratches” filter, though this will often soften your images depending on the settings you use.

3. Learn how to use layers. Most of the steps above can be handled via layers in Photoshop — this will allow you to undo your steps and see what effect your adjustments have on the photo. Layers will simplify your life.

4. Remove blemishes. The clone stamp tool in Photoshop is perfect for removing pimples, wires, and extra nipples on your subjects. Use it wisely.

5. Get better software. If your camera doesn’t come with a decent software bundle, don’t despair, you’re not stuck using Microsoft Paint. While Photoshop is expensive, the GIMP is free and lovely — and it offers most of Photoshop’s functionality. And also try Autostitch to create compelling panoramic shots.

6. Read up. Many sites offer photo editing tips — let Google be your friend. And Luminous Landscapes too (thanks Martin).