Change background and keep original shadows

Change background and keep original shadows

Sometimes you want to change the background of an image, containing a person, an object. Specially if you want to create a composite image. By simply selecting the subject and its shadow, it’s not always works and that’s not the way to do it . The natural shadow of the subject looks more realistic. Most of the time you will add a shadow in Photoshop to make objects, look more realistic and not floating in the air. In this example I am going to use an 3D image of a Lamborghini.

First step is to duplicate the layer. Once done, use the Lasso Tool to select the object only. This is important. We want to isolate the object from the shadows that is casting. Try to make a nice and clean selection. You can use Refine Edge after you have made the selection, to fine tune it. In my case, with the car, I have to make also a selection of the left side window. So when I change the background, it will be visible trough it to. Don’t forget to deselect the selection, we don’t need it anymore. Hide all the other Layers. The only layer visible is the original copy Layer 0.

 

So to be able to do this, hold Alt key. Once the selection of the object is done, invert the selection. Press Delete key to delete the background. Select the first layer and click to create a new layer. This new layer will be the background that we want.

 

Choose the color of your background. At this point, there is no shadows. The next step is to bring the shadows back in. As you can notice, the object seams to float in the background without the shadows. Unlock the Background layer, original image by double click on it. Move the Layer 1 at the bottom, see image reference. Hide all the other layers besides Layer 0.

Changing background and keeping original shadows
Changing background and keeping original shadows

So we are going to work on the original image to bring in the shadows. Start by Desaturate  the image. Press  Ctrl+Sgift+U this will Desaturate the image. Next step is to invert. Press Ctrl+I on the keyboard. This will help to see what we are doing. Bring up the Levels panel and darken the image. Use the left slider and start darkening the image, until the background is almost black. At this point you can see how the shadows are lighted up. You can control how much of the shadows you let in, by adjusting the left slider, the darks.

You can also use the middle slider for further adjustment. After this press OK. Now invert the image back again, Ctrl+I. Make all layers visible. Set the blending mode of the desaturated layer to Multiply. And you are almost done. In my image for this tutorial, the background of the original image is flat. Almost white, or more gray. You will notice other shadows around the background or foreground. I have some around the corners of the image. To remove those, simply make a layer mask to Layer 0. Use black brush on the mask, to remove parts that you don’t want.

.Now you can use Layer 1 to change to any  color you want. You can also use  it in a composite. And this is how you, can change background and keep original shadows.

Changing background and keeping original shadows
Changing background and keeping original shadows
Tudor
Tudor Catalin Gheorghe

As a photographer, my goal is to create beautiful imagery. I discovered that I can’t stop learning. It’s always something new that you can learn in photography. In my journey, I hope that I can teach others a few little things about photography and photo editing. I’m the author and the creator of this website.

2 Comments
  • Mahbubur Rahman Sohel
    Reply

    I need ur help to learn more thing about photo editing.

    January 3, 2017 at 15:06

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