online photo tutorials

In photography, timing is everything. Light changes often throughout the day, with the early morning or late afternoon lighting giving landscape photographs a soft appearance, without the harsh light of midday but with the edge definition that makes photos “come alive”. However, when traveling, you cannot always view landmarks when the light is best, and you often have to settle for hazy view that never appears as well in a photo as you remember it. With Photoshop, however, you can clean up your landscape images and remove the blue tint from the atmosphere seen most during over long distances at mid day.

Load the photograph you’d like to correct. In this situation, I’m using a photo taken at an 1800mm 35mm equivalent. That is a long lens. For comparison purposes, this photo was taken at 20mm with a Nikon D300.

Here is the hazy photograph that we’ll be editing in this tutorial, shown at the red box / center crop from the previous photo.

The first step is to create a new level adjustment layer. Click the layer adjustment button in the layers palette and select “Levels…” from the menu.

You should see a screen like this. This is the levels adjustment layer screen. The black graph in the center with the three distinct spikes is called a “histogram”. If the graph is farther to the left, it means there are more dark pixels in the image. If the graph is farther to the right, it means there are more bright pixels. If the graph is very flat or spread out, it indicates the photograph has high dynamic range. If the graph is very narrow, as it is here, it indicates narrow dynamic range.

Since we only want to remove the blue haze from the image, rather than the overall tone, we are going to work on the color channels, rather than the RGB or “composite” of the three channels. If we work on the RGB composite, we will be effecting brightness, rather than the balance of colors in the image. Press “CTRL + 1″ to edit the red channel alone, or press the “RGB” drop down menu at the top and select “Red”.

Click and drag the black point and white point sliders underneath the histogram to the edge of the histogram, marked by the black pixels at the bottom.

If you look at your image, you’ll notice this changes the amount of red in the image. At this step, the image will appear to be unnaturally blue since we’ve altered the level of red in the image.

Now, click either the “Green” section in the levels drop-down layer, or press “CTRL + 2″. Make the same adjustments to the green section as you did to the Red section.

Notice how the black and white point sliders have been dragged exactly to the start of the histogram, indicated by the edge of the black graph in the image.

Now, looking at your image, you should see that the colors are much more accurate. Press “OK” on the levels dialog box. However, we did not change the overall brightness of the image [by much], so it appears to be very dark. Double click on the levels adjustment layer in the layers palette, and this time edit the “RGB” section.

As you can see, the graph has changed quite a bit since the first step. The data is more spread out throughout the graph, indicating better tonal range, but it is clumped to the left, indicating under-exposure.

Drag the highlight slider on the right towards the center, looking at the image to determine when to stop. If you hold “ALT” while sliding, you’ll see the image turn black. As you slide to the left, some pixels will appear. This means these pixels are over exposed - past 100% brightness. Data is lost in these pixels, so it is best to avoid these in area you want to show detail.

After adjusting the brightness of the image using Levels, the image appears to be taken on a perfectly clear day. After a little bit of sharpening, the image looks much better than before.

If you have any questions on this tutorial, feel free to leave us a comment.

This post is tagged blue tint, haze, landscape, levels, telephoto