The Panorama Techniques or Bore Me To Tears

Posted in Photography Tricks on November 12th, 2009 by MadDog
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I’m not sure why I suddenly got the idea that somebody out there might be interested in this. My brain works, when it works, in mysterious ways.

I did a two-frame exposure with my Canon G0 a couple of days ago of a mediocre sunrise. As I was stitching it together and going through the process of determining if it was worth keeping, I began to think of the steps as a sort of dance with the pixels (don’t ask). So, from that demented state, this post was born.

Let’s start at the beginning. Well, not really at the beginning. We’ll start with the image that Photoshop coughs up after you load the two frames into its Photomerge feature. Here’s what you get if you are lucky and you’ve held the camera straight and overlapped the two shots correctly. It helps to have a “Panorama” setting on your camera, because it will set the exposure on the first frame and then keep it the same for each subsequent exposure. Otherwise, you might have to set your camera on manual or use an exposure lock feature, if you can find it. Anyway, here’s the starting point for our purpose:

The two-frame panorama as stitched together by Photoshop

As you can see, Photoshop had to do some fancy footwork to make the two frames blend together as if they were a single exposure. That’s why the shape is funny. If you’re doing more that two frames, it can get a little crazy. That’s why it’s always best to shoot several sequences of the same panorama. Hopefully, one of the sequences will come out more or less straight, indicating that you were holding the camera in a consistent way and lining the shots up correctly.

You can see in the shot above that the horizon bulges down a little and is slightly tilted. We use the controls in the Filter | Distort | Lens Correction feature of Photoshop to fix these problems:After straightening the curved horizon

Now we have a nice straight and level horizon, but the image is squeezed in at the bottom. If we don’t fix this, we’ll lose part of the sky when we crop it to a rectangle.

We use the same filter as before, except we use a different control to pull the bottom of the image out toward us. You can think of it as if you were looking at the image on a canvas and you tilted the top of the canvas back away from you. Now the image is more or less rectangular. We can get away with this in this image because we have no obvious lines that must be kept vertical or horizontal, except for the horizon, which we’ve already fixed:Stretching the bottom to make the image more rectangular

These controls are very handy for images that contain architecture. You can fix those buildings that look as if they are leaning back away from you.

Now, we crop (trim) the image so that looks compositionally correct. On this image it is a no-brainer. If we were dealing with other images we might want to think of the Rule of Thirds. Here, however, we just need to grab as much detail as we can:Cropping the image to the area of interest

Notice that, because I did not want to lose any of the detail high in the sky, I had to cheat on the crop a lttle at the upper corners. That’s no problem. We can use the Clone Stamp tool in Photoshop to pick up bits from one place in the image and blend it in somewhere else. This is one of the coolest things since sliced bread.

It this image you can see that I filled in the missing areas:Cloning in the missing bitsWe still have the problem of the boat intruding on the image, but we can fix that also by cloning some of the water near the boat to cover it up.

Now the boat is gone and all that is needed is to adjust the final colours:

Cloning the boat out and adjusting the final coloursThe whole job took about ten minutes. That’s far less time that it took to tell you how I did it.

If you like photography and you want to look like a pro, learn to use Photoshop. It’s the easiest fake-out job on the planet.

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