Q. How does a photographer catch the candid emotion, expression or action?
A. It can be difficult, however there is something consistently said by every portrait photographer I know, only 1 in every 10 is a good photo at best. The more experience in the portrait field, a photographer has I have heard the numbers dramatically increase from the 1 in 10 to 1 in 100.
I certainly found this to be true as I shot a wedding. Out of the hundreds of photos I got throughout the time of the wedding, reception and exit I only liked as many as 7! Remember though that I am coming from a viewpoint of quality and clarity, so even though the pose is good, I may not like it for smaller details that no one else might notice.
This may be a little steep for some photographers shooting film, so my caution to that is “Be careful on what you use your film.” In this age of technological advances and affordable digital cameras, use both styles (film and digital) but do not stop shooting with the digital until you get the right shot and then pick up your 35mm to get that one shot you found through the inexpensive digital shot. Do not hesitate either about deleting the digital photos! They essentially cost cents on the dollar as compared to the 35mm photo which costs a good part of a dollar if not more.
Q. How can a candid be posed with the same intensity of emotion?
Several things factor in but I will say one of the most important parts of getting that smile or intense concentration is being able to communicate that emotion to the subject. Now, for a truly candid shot being that the subject does not know they are being photographed means the photographer should be ready to take a minimum or 3 – 10 pictures in a burst so that you can choose from the best of the expressions. One last point is to do your best to get the surface of the eye in focus because the soul of the person and the eyes being the window to the soul will give the true emotional expression.