We can say that there are three situation in which one might use external material (photos, 3D renders, scans etc) in a painting:
- High level source material
- This is material that is directly used in a PS file, albeit moderated by masking, color adjustments, blend layer etc.
- Low level source material.
- This is material that is absorbed into the fabric of the painting.
- This is material that is referred to in the course of the painting.
Of course, between these three polarities are many nuances of difference.
High level source material
To a compositor the use of source material is a no brainer. A composite is by definition, for the most part, a collection of source material. However, the distance that an image can take from the source to the end result can still be substantial (see below for two sets of before and afters).
Though these images have been taken specially for the purpose of the painting, it is quiet common to grab images from the internets to be used in your work. However, there is the principle of creative ownership to observe. The image pair below represents a COMPLETELY UNACCEPTABLE instance of image use. The student has merely placed a background image behind someone else's work, with the bare minimum of intervention. They did not even change the pixel dimensions of the original! This work was not accepted as part of the student's final submission. A good policy is to choose images that are reasonable 'image neutral' such as holiday snaps. It is very difficult (though not impossible) to absorbe a large part of someone else's art work into your own.
Low level source material
Layer blends are often used to pass on complex texture information onto an image. Rather than make this information ourselves it is sometimes easier to grab it from Google images searches. It is usual that these images need to be treated in some way before they are usable: changed in size, chopped, de-saturated, saturated, lightness changed etc. This is often in observance to the neutral colors of the blend mode. Such information constitutes low level source material: completely absorbed into the fabric of the painting. In the example below a vivid sunset (inset) was used to enhance the colors of the sky on the left to produce the result on the right. AThe sky was blurred heavily and set to Hue blend mode. The Blend If values of the in the Layer Style dialogue box were then played with so that the blend was not passed onto the building.
In the image of the spaceman ('Hope') the texture of the air hoses on the spaced suite were achieved by manipulating an acquired photo of a woman wearing a pair of denim jeans, the result being blend-layered into pictorial coherence. In this way the reference material was completely absorbed into the fabric of the image.
Should an artist wish to paint a radio, they might take or find a photo of a exactly the radio they want and use that. Alternately, the following scenario might be observed: he Googles the term and find thirty images that are vaguely suitable. After scrutinizing these he identifies ten or so key 'rules' of 'old radio-ness' from which he paints the perfect old radio. The result not not look exactly like any of his thirty images, but embodies in some way all of them. This is how reference can work.
To some painters the use of reference is a substancial issue. Some of you who paint might feel a bit queazy about the use of reference in a painting. Here's the truth: there are very few naturalistic painters of any value that do not in some way use reference. I want you to understand that 'painting from imagination' is the exception not the rule.
The comic artist Glen Fabry can, without any doubt, really draw. However he still | takes photos that he uses in his work. His photography is not the best but it serves the purpose. He also | uses the 3D figure posing app Poseur to get the lighting right. You can see in both instances that he takes his reference material a long way.
There is a pint between painting and compositing that, to my mind is all the more interesting as a result. Look at the painting below by the artist Sara Chong...
Here is some of the reference material from which it was sourced. This was part composited, part painted part I-dont-know-what.
Even the worst photo and (to a lesser extent) painting has a degree of inherent unity. A student's painting and, even more so, their composites, can often look hesitant and 'bity' and looks no more than the sum of its parts. Exactly why this is so is something of a mysterious issue. Certainly good element matching can help, but also good image construction skills are needed. Particular attention should be paid to the distribution of elements across the scale range. In the case of discrete objects within the image these 'should' be large, medium and small ones. Remember this: in a traditional painting the brushstrokes made with the fingertips, wrist, forearm, full arm and full body are all distinct and all serve different functions.
Some of these files are in the Assets page.