Last August I talked about using automatic modes and how many professionals use them to enhance their artistic results. Recently the topic has resurfaced so I thought I'd discuss it again.
Most cameras now days give you several options for allowing it to determine exposure for you. This is a pretty hot topic for many professionals and as you would expect there are about as many opinions as there are automatic modes. As usual I'll give you my opinion. Doesn't make it right but hopefully it will give you something to think about.
Professionals that shoot in manual mode usually take issue with the camera determining any of the aspects of exposure. To them it removes their decision making and, therefore, control over how light is measured. After all, the camera is just a computer with it's pragmatic rules for how to see the light and as a result set the components of exposure. There are many situations where the camera gets it wrong. It can't always know what your intentions were. A back lit portrait is a good example. In full automatic mode the computer in the camera will look to determine the exposure of the entire image. Therefore, all of the light spilling in from the background will tell the computer that the image is well lit and reduce the amount of light on to the sensor. This will result in a dark subject in the foreground. The computer did it's job but yielded an undesirable result.
This sounds like a testimonial to always shoot in manual mode, however, my opinion is that there are very valid times to use some of the automatic modes and many professionals agree with me. When shooting in an automatic mode you must do so with a good understanding of what the camera is doing so you can make adjustments in particular circumstances. I call this semi manual mode and I will explain in a moment. First, let's discuss the automatic modes.
I cannot think of a situation where full automatic mode makes sense for my photography. This is because it takes total control out of my hands. This means it removes any creativity I may want for the image and I am at the mercy of the programmers that designed the camera computer. I may get good exposure, but it's not my image, it's the computer's. That being said, I can think of many situations where I can use some of the semi manual modes (ex. Shutter Priority, AV Mode, Auto White Balance, and Automatic ISO). Let's talk about each one individually.
Shutter Priority mode is where you dial in the shutter speed you want and then let the camera determine the appropriate Aperture to get a good exposure. When I shoot sports I usually shoot in Shutter Priority automatic mode. I want to be sure that I stop the action but can't shoot in manual mode because the light is constantly changing. The Aperture doesn't matter and is usually fairly wide by default. In my case, I shoot high school football from evening into the night in a stadium with fairly poor lighting. The end zone lighting is worse than at mid field so rather than constantly changing my Aperture I use this automatic mode.
Almost all of my sports images are shot in Shutter Priority mode
Portraits are a different story for me. If I'm in studio I always shoot in manual mode. Since I use strobes or constant lights I have complete control over the light. This allows me to set my shutter speed (sync speed) and then I can be creative with my Aperture and ISO. By the way I always us an incident light meter in the studio. It's much more accurate than the camera meter.
I usually shoot differently if I'm not in the studio. For these types of portraits I usually shoot in Aperture Priority or AV Mode. This is where I dial in the Aperture I want to use and let the camera determine the shutter speed. I use this mode because depth of field is the most important aspect of these shoots. If the light isn't changing a lot I may switch to manual mode, but usually not. I'm OK with the camera determining the shutter speed as long as I keep an eye on what the camera determines is appropriate. If I allow the shutter speed to get too low there will be the probability that there will be camera shake resulting in a soft image. I like this mode too because the camera computer will determine the exact exposure which may be in fractional stops. For example the computer may decide an appropriate shutter speed of 1/425, where I can't actually dial that in manually. I also use this mode for landscapes. Again, I am most concerned with depth of field because I want foreground, middle ground, and background to all be in perfect focus so I want a very broad depth of field. Since I shoot these primarily on a tripod I don't really care about shutter speed. Unless, of course, it's a windy day and I don't want blurry trees or grass.
Shot in partial sun in Aperture Priority (AV) Mode
Almost every photographer you will talk to will take a stance against using Automatic White balance. However, there are times when I use it effectively. I use this only when I am forced to and it's when the light is constantly changing. This may be with landscapes where cloud cover comes and goes or shooting concerts or indoor events where there are spot lights and ever changing color filters being used. However, if the color of light is pretty constant I will try to either take a custom white balance with my Expo Disc or use one of the presets on the camera. Presets are usually better than automatic but not always. Also, if you shoot in Raw you can update the white balance after the fact. It's just a pain and can really be time consuming. The bottom line is don't use it unless you have to.
Using the automatic ISO mode is something I didn't get into until recently. ISO is usually one of the last adjustments photographers think about, especially the amateur or enthusiast. I think this is because it's not really thought of as a creative tool like the others. One way to use Auto ISO creatively is to allow your camera to determine the ISO with limits while you manually set your shutter speed and Aperture. What do I mean by this? The Auto ISO mode allows you to limit the high end ISO amount that you will allow the camera to make when adjusting that value. For example, if you're not comfortable with an ISO over 1600 you can set the limit for the Auto ISO at that value. The computer in the camera will then automatically determine exposure and adjust your ISO not to exceed 1600. The setting also allows you to give it a starting point, such as ISO 400. Therefore, in this example the computer will give you the lowest ISO possible between 400 and 1600. Most high end cameras now days shoot acceptable images up to 1600, especially if you're only planning on using it online, or not expecting to print it bigger than 8 X 10.
My reference to using these in a semi manual way was meant to describe how you can make adjustments to what the camera determines is a perfect exposure. High end as well as some mid level cameras will include what is called "Exposure Compensation". While in an automatic mode this setting allows you to adjust what the camera has automatically set. For example, while in Aperture Priority mode you can use the exposure compensation to change what the camera determines is the perfect setting for shutter speed. However, you must be aware that the overall exposure will change. So if the camera determines the shutter speed should be 1/500 and you set the exposure compensation to change it by -1 stop, then your shutter speed has now changed to 1/250 and thus the overall light is reduced by one stop. I use this frequently when shooting outdoor portraits to darken the sky and make it a deeper blue. Then I use speed lights to lighten the subject. Again, I like this because it can determine fractional stops that I cannot directly dial in myself.
Shot in Aperture Priority (AV) mode with -.3 Exposure Compensation
to darken the back ground
The bottom line to me is that it really doesn't matter if you use manual mode or an automatic mode as long as you know what is going on and take measures to get what you want. In my opinion, just because you shoot in manual mode doesn't make you a professional. Conversely, if you shoot in an automatic mode doesn't mean you aren't a professional. It's the final result that matters. How you get there is up to you.