We are going to start dissecting the subject of Photoshop Realism or Lack Thereof with lighting because it is the one area that I was victim of in my early days as a designer. Think about this for a moment. Everything we see, we see because of light. Without light we do not see. So you would think that all of us being experts of seeing things that it would be obvious when something isn't right. Yet so many of us fall victim in Photoshop to creating things that don't look right and quite frankly are impossible! Let me walk you through some examples of terrible lighting scenarios. Notice in a lot of these samples that the problem focuses on the shadows. Light creates shadows and a lot of time the shadow is the indicator of the problem.
While the overall style of this image is nice there is a glaring flaw present. My diagnosis of this image is that the soccer ball and legs were photographed together and the were “comped” (designer slang for composite) into the grass and sky scene. The lighting issue here is that the legs and ball are very will lit from the front but the shadow is coming towards the front of the picture. Why would a shadow be cast in that direction but the entire side of the legs and soccer ball be so well lit? They shouldn't be. It is for that reason that the sky in behind creates a visual conflict. We see a semi-cloud covered sun. I know the sun is the reason the creator put in the hard shadow, but who has a hard shadow when the sun isn't out in full?
In this image I am assuming that the sky, climber and cliff were all separate images. How I know this is there is a sunset image in behind a cliff that is completely lit from the front. Then we have a climber that is back lit but has highlights to their front side while the sun is more towards their backside.
Again we have subject matter that should be a silhouette because of the dark nature of the sky with the back lighting. Let's suppose that you really wanted to use the picture of the geese and wanted to see the detail in them. This would mean that the sky needs to be changed. Looking at the geese you would need to select a sky that gives the impression of the sun being at about ten or eleven o'clock and in front and to the left of the geese. You at least need to start with a sky that holds those lighting properties then you could start to play with it in PS is you wanted it to have high contrast and moody sky like the lighting on the geese.
This image makes me smile because I know the creator of it meant well but there are so many problems here. In this image he have a storm scene with an arm sticking out of the sky that looks like it was photographed under the florescent lighting of an office. Not that its a bad arm to start with but there needs to be the commitment to see the job through. The arm needs a lot of work with other shadowing and light sources added for it to look like it belongs in this environment. If your not sure what you are doing trying to create a piece like this look for tutorials online and learn something new. Thats a better route than putting your name on something second rate.
I really really really dislike images like this one. They are so contrived it makes me feel nauseous. There are so many flaws in this image when it comes to lighting, not necessarily with the direction of the light but rather the consistency of the lighting and skin tones of all the individuals. If something like this is to be completed properly certainly requires a lot of time in PS or all the people would need to be photographed the same day under the same lighting. Then the could be comped together.
To conclude it takes a trained eye to look for and plan for all the considerations that come into play when creating a composite image in PS. It's my hope that this post will help to give you a new eye to see these things. When done right some really stunning work can be created. Good luck and post any questions if you have them.
*All images from dreamstime