Their are some key factors that you should know about to judge whether a photograph is of a high quality and professional. These key factors include, but are not limited to, Composition, Lighting, Focus, Posing, Attention to Detail, Variety and Perspective.
Composition.
Composition is the way in which an image is composed. There are many rules which outline what constitutes good composition and I will try and describe them as best I can with examples.
Another element to take into consideration with composition are leading lines within the image. Some leading lines are good ones, pointing to the focal point and adding impact to the subject within an image. In contrast, some leading lines are detrimental to an image, they take away focus from the subject or split an image in two making an image difficult to flow compositionally. Lines can be of any type, straight wiggly, diagonal, anything that the eye can follow through the image. Depending on the image content lines can frame a subject within the frame of the photograph itself see below where the lines of the sofa frame Mia:
Below is an example of bad composition, there is negative space behind baby's head, the crop is too close to the right of his little face and he is looking out of shot which stumps the flow of the image as the viewers eye imagines what he is looking at and realises there is nothing to look at not even negative space.
Lighting is one of the most important elements in photography, if you can get your lighting spot on every time you can practice all of the other creative elements of photography and always have a perfectly exposed photograph.
Photographs are easy to overexpose especially because over exposure tends to make skin look clearer as it bleaches out any impurities. This is not the way to smooth out skin. Good photographers will be able to spot heal any blemished and skin tone should be as natural as it is in real life. You should always be able to see the different skin tones and pores if the picture is a close up. Here is an example of an over exposed image:
Below is an example of the same photograph that has been under exposed.
Below is the photograph correctly exposed.
One of the most common mistakes and tell tale signs of an amateur photographer is the use of flash and the positioning of shadows within a photograph. The flash when used without a diffuser or without being bounced before lighting the subject is often very harsh creating strong shadows which outline the subject against a wall. I regularly see this in wedding photographs and am shocked because of the importance of the photographs. If you are given the privilege of being hired to photograph the most important day of a couple's lives then you should make sure you are qualified to do so. Especially if you consider yourself to be professional and charge professional prices. The lighting should be even and natural or set up specifically to studio standards not done half arsed with horrible dark shadows and bleached out portraits.
I will write about the other topics in my next post.
Thanks for reading :D