Photoshop can be used for many things. One of these things is editing photographs, putting people or objects in environments that they were not originally in. However, there are many problems that arise when doing something like this, the main thing being that the resulting picture looks fabricated and not natural.
Adding a shadow can really persuade the viewer that the person or object was originally in the photograph when it was taken. Also, shadows give weight to a person or object if you are just going to isolate them and place them on a solid background, white for example. Shadows allow the object or person to avoid looking like they were isolated out, just cut and pasted.
Following these simple steps, you can easily create shadows and adjust them however way you want to. This tutorial will demonstrate how to create multiple types of shadows on a solid white background. This will allow you to see how it works and can implement the technique to suite your needs.
Casting a Shadow
Step 1: Isolating
The first step would be to isolate the object that will be casting the shadow. This can be done using a variety of methods, some more successful than others. The best approach would be to use the pen tool. Another way is to use the selection tool. However, for purposes of this tutorial, I will be assuming that you will be using the pen tool.
Isolating the object serves two purposes, and kills two birds with one stone. First, by isolating the object you can copy and paste it to the background that you want. Second, the selection can be used to create the shadow.
Once you have the object pen pathed, make it a selection by going to the paths tab, right clicking on the path, and selecting “make selection”. Once it is selected, feather it 1px.
Copy and paste the selected object onto a new layer and de-select. Create a new layer right above the background layer. Fill that layer with a solid white and rename it to “white background”.
The layer with the isolated object should be named something to let you know what it is. For the sake of this tutorial, I will call it “Iso Object”.
Once all this is done, on your screen you should see a white background with the object on top of it. Looks pretty fake huh? Well, we’re about to change that.
Step 2. Creating the Shadow
The next thing to do is to make the shadow. To do this, make the background layer your active layer and turn off the other two layers. Then, go back to your path tab and reselect the path you created in step one. Again, make it a selection and copy and paste it onto a new layer. You won’t need to feather it, but if you want to, you can. It’s not necessary however. Before de-selecting it, fill the selection with 100% black. Then, de-select.
Once the new layer has been created, rename it to something like “Shadow”. After that, turn back on the other two layers and place the Shadow layer between the Iso Object layer (which is the top most layer) and the White Background layer.
Making sure the active layer is the Shadow layer, apply a Gaussian Blur effect on that layer. The more effect you put on, the fuzzier the shadow will become. Mess with the blurring slider until you get to a consistency that you like. It also helps if you have the Iso Object layer turned off. Once you have it to a setting that you like, hit OK and exit out of the Gaussian Blur window. at this time, turn the Iso Object layer back on if you turned it off, however keep the active layer the Shadow layer.
The next thing to do is to go to Edit then Transform then Free Transform. Moving the top corner points only, you can drag it down and closer in together to create an illusion that the shadow is being cast towards the horizon.
Step 3. Making the Shadow Look More Believable
Once you have the shadow at an angle that you like, add a mask to that layer. You can also adjust the Gaussian Blur if you are not satisfied with it after seeing it cast. Once you have the mask set, use the gradient tool and put a gradient effect on the mask with black changing to white, top to bottom. If done correctly, this will cause the drop shadow to be darker near where it meets the person or object and lighter as it moves towards the horizon. You can keep applying the gradient until you get a result that is satisfactory.
After that is done, you should drop the opacity of the layer a bit because a 100% black shadow at the meeting of the object and shadow is too much. Drop it down a bit till you are satisfied with the darkness of the shadow.
Drop shadows work well with objects, so for the sake of this tutorial, i will be using an opened pocket knife. The names of the layers will remain the same as the names used in the example above.
The first step is the same as if you were creating a cast shadow. The second step is the same up until using the Free Transform. Stop after you have applied the Gaussian Blur effect and proceed with the following steps.
Step 2. Creating the Shadow Continued
Once the Gaussian Blur effect is in place, (make sure the Iso Object layer is turned on) shift the Shadow layer down a little bit so that more of the black is seen at the bottom of the pocket knife. Do not bring it down too much or you will lose the effect. The resulting image should make the pocket knife look like it has a drop shadow. However, there are a few other finishing touches to make it look even better.
Step 3. Finishing Touches
Again, making the Shadow layer the active layer, add a mask to it. Once that is done, use the paint brush set to 100% black and go over the areas where there shouldn’t be any shadow. For example, the top of the pocket knife might have traces of black from the shadow. Go around the edges of the object to get rid of any access shadows but stay away from the areas that you want to keep the shadow. Make sure this is being done on the mask layer.
Once that is done, it’s good to lower the opacity on the Shadow layer as well. Making the shadow too dark will cause it to loose the effect of realism.
There are many other ways to create shadows in Photoshop, but these are just two. Even with these techniques other techniques can be added to create some interesting effects. The best way to learn however is to try it out yourself. Apply knowledge about other aspects of photo editing to these techniques and see where they lead you!