Before the invention of photography artists always had their subjects model for them in order to draw or paint their portraits. This practice is very deep in the tradition of portraiture. Of course, after photography became available artists' options for creating portraits were expanded. This included using photography as the final medium, as well as a tool to help create drawings or paintings without having the subject model for the artist in the studio. Today, many artists choose to use a combination of both approaches when doing portraits. There are also artists that use only on form or the other for various reasons. Each approach has pros and cons that will be discussed in this article.
Using a Live Model
Many artists will tell you that this is still the best way to create a portrait. It certainly has the most weight as far as tradition is concerned. It has been tried and tested through hundreds of years of practice. And in many ways, I think this is the most rewarding approach. It's very interactive, and the resulting portrait will capture the dynamics of the relationship between the model and the artist. There are some intangible qualities that this approach offers which are not possible using a photograph. From a technical standpoint, the values will be more precise and the artist will be able to see very subtle differences in the shading and highlights that are sometimes lost in a photograph. Of course, I'm not saying that these subtleties cannot be maintained by a good photographer. However, most average photographs lose those qualities to some extent. Similarly, a lot of smaller details can easily be lost in photo references. Small details in jewelry, for example, may be visible in person, but may not be able to be distinguished in a photo. Again, photographers that use larger negatives or more high-definition digital cameras can get good detail. But,chances are, if you are going to those ends to achieve that level of quality you probably should just be using photography as your final medium.
There are drawbacks to drawing from a live model though. First, it takes a lot more skill to draw from a live model. You are creating a two-dimensional image from a three-dimensional image. With practice, both can be done with equal effort, but for a beginner drawing from photographs is an easier way to begin. Also, models have to sit for extended periods of time. No matter how still the model attempts to be he/she will eventually change position. The longer they sit, the more drastic those changes will be. A good artist will be able to incorporate those differences into the portrait, but I have seen many novice artists really struggle with moving models. The other drawback to live modelling is the convenience factor. Long periods of time have to be set aside (usually more than once) to work on the portrait. These times have to be coordinated between the artist and the sitter. When just practicing this is usually not a big deal, but if you are trying to make a living drawing portraits it decreases your flexibility with your business hours and can become extra hard when you and your client live in different places.
Using Photo References
Just as many artists prefer to use only live models, others use photographs only as a basis for their portrait references. The benefits of using photos are directly related to the drawbacks of using a live model. Photos allow the artist to really analyze a person's face (or figure) without making the subject uncomfortable. While professional figure models may be used to classes of art students staring intensely at them for hours straight, many would-be portrait clients may feel a little uneasy with that. However, in order for the artist to get an accurate rendering he/she must look closely. Photographs also allow for the artist to draw the subject without the worry of positioning changes. And, of course, it doesn't require the subject to be present. This may be something that is important to either the subject and/or the artist.
The primary drawbacks to using photo references were listed in the above section. The most critical issue I have noticed about artists who work only from photographs is that the resulting drawings tend to be very flat and lifeless. This isn't always true, and it can be overcome by an artist who has also done a lot of drawings from live models. But it is easy to become too analytical and "stiff" when working from photos. I wouldn't recommend it as your only approach. If you choose to do most of your portraits by photo reference I would at least keep brushed up on figure drawing skills at a local figure drawing class with a live model from time to time.
So What's the Verdict?
My professional opinion is that portrait artists should find a way to use both techniques to some extent. Many artists today will arrange one sitting with the sitter to get some live sketches down. They will use the same sitting to take some reference photos to use to finish the portrait. This seems to work very well with a lot of people. It allows you to get the best of both methods.