Digital Photography 101, Part 1

 

Shooting Mode Options and Basic Exposure
Shutter speed, f-stops, Depth of Field and Exposure

This article is about the basics of photography that you have to know before you can improve.

All of the images in this article are from the New England pictures I shot in the fall of 2006.
To see a larger picture and information about the image, just click on the image.

 

 

Intoduction to Digital Photography 101

This article started out to be about "Setting Up Digital Cameras" but it soon became evident that it was really more of an introduction to the basics of digital photography. I discoved that digital camera setup didn't make much sense if you didn't understand the basics of digital photography. So, I began to get sidetracked into explaning how to shoot digitally.

If you find yourself rapidly gettting lost with talk of f-stops and exposure compensation and Raw Format, this article is a good place to begin.

Each of the five articles in this series begins with some aspect of digital camera setup and then digresses into imporant basics that all photographers have to know if they are to shoot decent images. A link to the next article in the series can be found at the bottom of every article.

 


Modern digital cameras come with operating manuals the size of telephone books and have an over abundance of dials, buttons, functions, gizmos and special features that can be quite bewildering. Actually, it isn't as bad as it looks since most digital camera options can be simplified into just a few categories. It is important to understand the more important of these options; if you don't, you are going to miss some of the best features of digital photography. An added bonus is that once you understand the basic setup of a digital camera, you are well on your way to a solid understanding of digital photography.

All digital cameras have several shooting modes. These modes are generally accessed from a dial on the top or back of most cameras. The various options will usually contain settings called P, A, S, M and maybe a star and moon logo for night and a mountain logo for landscape. More expensive cameras may have a bunch more, but these are the basics.

"P" on the mode dial stands for program or fully automatic mode. If you are a novice photographer I would begin by setting your camera to this setting. The "P" setting is also a good place to leave your camera set to when you are not using it for a special purpose. The "P" setting will choose the best overall setting for lens aperture, shutter speed, ISO, white balance and whether or not to use flash. It is important to realize that this setting is not just for idiots who know nothing about cameras, it actually works very well in most situations. If you are going to be hand-holding the camera, i.e. not using a tripod, the "P" setting will get very good results. You would be suprized at the number of pros who use the P setting most of the time.

"A" on the mode dial stands for aperture priority. If you choose the "A" setting, you will be able to select a lens aperture, also called an f-stop, with a dial someplace on the camera. The lens aperture is basically the varibly sized opening in the front of the lens that allows light to come into the camera and hit the digital sensor. Lens aperture is one of the two exposure controls on any kind of camera, digital or film. The other control is shutter speed. Aperture and shutter speed work together to control exposure. The two controls have a reciprocal relationship. The wider the aperture, the faster the shutter speed must be. The smaller the apeture the slower the shutter speed must be. Any exposure can be achieved using a number of aperture/speed combinations. For instance, f-8 at 1/60 is exactly the same exposure as f-11 at 1/30. Every aperture one size larger allows exactly twice as much light to flow into the camera and every shutter speed one step slower also allows twice as much light to flow into the camera. As aperatures get smaller and speeds get faster, the light is cut exactly in half with each step. Every step up or down in either aperature or speed is called a stop.

OK, back to the aperture priority setting. Once you select the aperture you want, the correct shutter speed to give you the proper exposure will be automatically selected by the camera. Choosing the correct aperture is important because aperature size gives you control of depth of field. Smaller apertures give you longer depths of field and larger apertures give you shorter depths of field. I have an entire article on Depth of Field and how to use it, but here are the basics. A long depth of field keeps everything from very close up all the way back to the far distance very sharp, and a short depth of field keeps only the subject you are focusing on sharp while the rest of the picture blurs. This all sounds very complicated when I explain it, however once you try it you will see that it is very easy.

A long depth of field is essential if you want to get that picture where the wildflowers right in front of the camera are sharp and the mountains two miles away are also sharp. A short depth of field makes it possible to take a picture of a very sharp flower or face that is surrounded by a nice artistic blur.

One slightly confusing point is that small apertures have large numbers and large apertures have small numbers. For instance f-22 is a very small aperture and f-2 is a very large aperture. Read my article on Depth of Field to get much more information on how to use this very important technique of contolling sharpness in various parts of the picture. This is one of the most critical parts of good photography. If you don't know how to do it, you are really missing out.

"S" on the mode dial stands for shutter priority. If you choose the "S" mode, the same dial that allowed you to choose aperature size will now allow you to choose shutter speed. When your camera is set to "S", every shot will be at the same shutter speed, the one you chose, and the corresponding aperture size will be automatically set by the camera for the correct exposure. The main reason for choosing shutter speed is the ability to capture fast action. If it is a bright day and you are photographing your son's football game, choose a fast speed like 1/500 of a second or faster to capture all the action in sharp pictures. (It will say 500 on the speed dial, not 1/500.) The faster the speed, the faster the action you can stop. As a general rule of thumb, you need to be shooting at 125 if you are hand-holding the camera and there is no action. 250 will stop a lot of action. 500 will usually stop most action that is moving from side to side in front of you. 1000 or 1500 should do the job for almost anything.

There is a limit to how fast you can shoot though. If your son's football game is taking place in the late afternoon and the light is not all that bright, you may have to settle for 125. The problem is that the faster the shutter speed you choose, the wider the lens aperature must be to get the proper exposure. After a while the camera runs out of available aperatures and then the camera will tell you that there isn't enough light and a flash will have to be used. The problem with flash is that it only carries 15 or 20 feet or so and this isn't much help when your son is 100 yards away. If you shoot too fast for the available light, distant subjects will be underexposed, even completely black, even though the flash fires. The solution is to choose a shutter speed that will just barely freeze the action, or at least most of the action, but is slow enough to expose the image properly. The reason the pro photographers at professional football games have those huge lenses is not only because they are telephoto lens, but also because they have a huge piece on glass in the front end, sometimes as much as ten inches in diameter, to let in immense amounts of light that allows them to shoot at very large apertures and thus very fast speeds. Anyway, select "S" in situations when you have to freeze action and watch out that you aren't shooting to fast for the available light.

"M" stands for manual. This means what it looks like, everything must be manually set by you. This includes aperture size, shutter speed, and sometimes white balance. There is only one situation when I use manual, when I am shooting a series of pictures which I intend to combine later into a long panoramic. Making panoramics this way is a wonderful thing to be able to do and not all that hard once you know a few tricks. For one thing, shooting a panoramic in three or even five shots is like shooting the picture with a camera that has three or five times as many megapixels. (One of these days soon I need to write an article on exactly how to do this.) Anyway, when you shoot individual shots for panoramics, it is essential that all the pieces be exactly the same brightness and color and shot at the same aperture size. If you leave the camera set to P or S or A, it will automatically set the exposure and white balance for each shot and often it will choose a slightly different setting for each exposure. This slight difference in exposure is enough to make it impossible to stitch the pieces of the panoramic together seamlessly. The "M" setting makes sure every exposure is the exact same brightness and color. If you don't plan on shooting panoramics in multiple shots, I would forget about the M setting.

"L" or a picture of mountains on the mode dial stands for landscape and is used when you are taking a big wide picture of a huge landscape. About all the setting actually does is set the lens aperture at a very small f-stop and focuses the lens at infinity. This will work, sort of, if you don't have foreground that is quite close. It works much better to use the depth of field rules that I explain in my depth of field article.

"N" or a logo of moon and stars on the mode dial stands for night and is supposedly the setting to use when shooting at night. Generally all the N mode does is set the camera for slower shutter speeds than normal. I think this setting is generally a waste of time. It doesn't hurt to give it a try though. When I am shooting in very low light situations I mostly take a shot at whatever the camera says is the correct exposure and then look at the LCD screen to see what it looks like. Usually the scene will look way too light as the camera will try to make the picture into a daytime scene. So I generally will try shots that are one, two or three stops underexposed using the exposure compensation dial, and then look at the shots on the LCD screen. (The compensation dial allows you to increase or decrease the auto exposure by one or two or three or more stops. This is another subject that I need to write an article on.) A little trial and error will generally result in the proper night time exposure. A little bracketing in this situation is also a help. Bracketing simply means deliberately shooting a series of under exposures and overexposures because it is sometimes hard to determine the exact correct exposure on the scene. If you bracket enough, something will be right and you will be covered.

If you have any questions about this article, or any of my articles, just email me.

Go article 2 in Digital Photography 101 series.