Since Im a noob to this world, Ive been doing A TON of reading while I wait for my D90 to arrive/before I go to Yellowstone so I can hopefully take some decent pictures.
Here are a few basic things I've learned along the way that should help my fellow noobs (it is in very very basic/laymans terms and the numbers are just for example purposes):
Photography is all about light
, as basic as it seems. Too much light in = an overexposed/whiter picture, too little light = underexposed/blacker picture. This light talk, which is affected by a variety of inputs, is called Exposure
How does this light enter into the camera?
Apeture and shutter speed (ISO does too but Im not 100% on its effect, I just know I need more if its darker)
This is the "F.#" (f1.2, f5, f11, f20, etc...). Think of it like a circle that opens a closes...the lower the "f.#" (f.1.2) the more open the apeture/wide circle is, thus letting more light in. The higher the "f.#" (f.24), the more closed the apeture is/tighter circle, thus letting less light in. The setting of the apeture are called "F-stops".
Here is a visual demonstration on the apeture opening/closing: http://asia.olympus-global.com/imsg/...ity/index.html
The apeture often controls the Depth of Field...DoF
. DoF, basically, is what is in focus in the picture; a shallow DoF means the closer objects are in focus and the background is blurry...a larger DoF means to more of the picture is in focus. The lower the apeture (lower number/larger opening) the more shallow the DoF/fewer objects will be in focus, with either the foreground or background being blurry . The higher the apeture (higher number/smaller opening) the more the entire picture is in focus.
DoF Example...remember, the lower the F stop/F#, the shallower the DoF, the higher the Fstop, the deeper the DoF
This is the "1/#" 1/1 would be a slow shutter speed, while 1/1000 would be a fast shutter speed. The LONGER the shutter stays open (the slower the shutter/smaller denominator), the MORE light enters the camera. The SHORTER the amount of time the shutter is open (faster shutter/higher denominator), the LESS light enters the camera.
Shutter speed is used to determine the "motion" of the subject. If a subject is moving you want a faster shutter to "freeze" the subject (like a flying football). If the shutter is too slow on a moving object, it will result in blurry pictures. Slower shutter are used to capture motion (those cool firework shots/tail light shots on the highway that reach the entire length of the highway)
edit(6/29/2009): Just remembered something about the length of time the shutter is open/closed. The slower the shutter speed (remember, the lower denominator), the more vulnerable the pictures are to blurriness due to the natural shake of your hand (think about it, the longer the shutter stays open, the slower the camera takes the picture, thus allowing more movement from your hand to effect/blur the picture)
-Apeture vs shutter speed
The more open the apeture (think lower F.#) the more light entering into the camera, thus you need a faster shutter (think higher number) to keep light out so your pictures are not overexposed...The more closed the apeture (think higher F.#) the less light enters the camera, thus you need a slower shutter (think lower number) to compensate for the little light entering the camera so your pictures are not underexposed.
Now that your confused, lets talk about Apeture Priority and Shutter Priority; very useful settings.
You control/set the apeture and the camera figures out the rest. An example when you want to control the Apeture would be taking portraits, flower pics, front wheel shots, etc...so that the close object is in focus and the background is blurry. Remember how to do this??? A lower F.#.
You control/set the shutter speed and the camera figures out the rest. You would want this when the action is moving around. Remember, a faster shutter (higher denominator 1/1000) will "freeze" and object in motion. Adjust your Shutter depending on the speed of your object.
Compliments of TurboFan:
The ISO number defines just how sensitive the sensor is to light. The degree of sensitivity any given “ISO” delivers is difficult to put your finger on, as it is a standard created by scientists and not something intuitive to the eye or mind. It is stated as a number, with ISO 100 being the lowest in most digital camera systems (ISO 200 in some Nikons). The term “ISO 100,” for example, means nothing onto itself, but in the context of the scene, brightness, aperture and shutter speed values it is a very key element in determining exposure and exposure values. It is part of an elegant, balanced system of exposure.
When the light gets low and the shutter speed gets slow it is a good idea to ensure a steady shot by using a high ISO setting. One of the real advantages of digital is that you can change ISO on every frame. This twilight shot was made on the docks at ISO 1000.
ISO poses part of an exposure solution to a given light level. For example, at ISO 100 on a bright day the correct exposure is usually around f/16 at 1/125 sec, or the so-called “sunny 16” rule. (This says that if your meter is broken and you have to set exposure yourself and it’s sunny out with the sun coming over your shoulder you can set the ISO at 100 and have a great exposure at f/16 at 1/125 sec—and it works!)
The sensitivity of the sensor is calibrated by your setting an ISO number. In round numbers, many cameras offer a range between ISO 100 and 1600, with some going up to ISO 3200 and beyond. Every time you double the speed, or ISO, you are in effect doubling the sensitivity of the sensor, or adding a “stop” of sensitivity to light. But this doubling of sensitivity only makes sense in the context of the aperture and shutter speed settings, which control the amount of light reaching the sensor.
There are times when flash is not allowed or would ruin the character of the shot, and that’s when high ISO comes into play. This photo inside a New Orleans curio shop was made at ISO 2400 handheld.
So, if for any reason you need more or less light to affect how the aperture and shutter speed are set, you simply raise or lower the ISO setting in the camera. Go to a higher number for more light sensitivity (when you need a faster shutter speed or narrower aperture) or a lower ISO for less light sensitivity (when you want a wider aperture or slower shutter speed).
You might think all shots made in low light or after sunset require a high ISO, but that’s only if you shoot handheld. Mount the camera on a tripod and you can shoot at lower ISO settings, which generally yield much less “noise.” That’s the case with these low-light shots. The classic Las Vegas neon cowboy was photographed at ISO 200 and the fireworks at ISO 100, both on tripod, albeit with slow shutter speeds.
In general, you will usually need a higher ISO setting in low light and want a lower ISO setting in bright light. Why not just set the highest ISO for every shot? Another rule to keep in mind is: the lower the ISO setting the better the quality of the image, all else being equal. That’s because to get more light sensitivity a gain, or additional charge is applied across the sensor. As you go higher in ISO this gain adds more noise to the image.
Many people choose to leave this in auto, but I think that is a terrible mistake. White balance gives me as much creative control of my images as any other setting on the camera. White balance simply tells the camera what is supposed to be white, and everything else is scaled from there.
Back in the days of film, you had to either select a film for your application, or use a filter to adjust the lighting coming into the camera. As a beginning photographer, it's important to know that not all light is created equally. Your typical light bulb has a very severe yellow tint to it. Fluorescent lighting has a very blue hue. Flash? Different still. Sunny day? This is considered to be true "white light" by most, having an equal concentration of each color of the spectrum.
If you take a picture that is illuminated by an incandescent lamp, and you have your white balance set to fluorescent, the image will appear very yellow. The camera will try and shift the color spectrum to yellow, because you told it the light source is very blue. Since the light source is already very yellow, it makes the problem that much worse.
If you take a picture in an office, where everything is illuminated by fluorescent lamps, and you are set for incandescent (regular light bulb) it will all be very blue.
If you are set for auto white balance, the camera does an OK job picking out the light color, but the camera still has to guess what is supposed to be white. If you don't have a good range of color in the picture, the camera may not guess right. I don't use auto white balance, ever.
Many cameras have additional settings for white balance. One is where you can set the color of your light source (expressed in degrees Kelvin, or K). A typical number would range from 2500k to 10000k. The higher the number, the more blue the source. Lower, more yellow. Another common setting is a pre-defined white balance. In this case, you take a picture of a white card under your light source, effectively telling the camera "this is white today". This is a very useful setting if you are shooting in controlled light, such as a studio.
Many photographers stress the 3 factors: Aperture, Shutter Speed and ISO so much because these factors cannot usually be rescued by post processing:
Aperture: if your DOF is too shallow hence creating desire area to be out of focus, there is no perfect way to get them back on focus again.
Shutter Speed: if there is motion blur to the camera, there's also no perfect way to fix them 100%
ISO: the graininess introduce by high ISO would also be non-fixable during post-processing.
I finally got these down and it took a few days of being confused before finally figuring it out (I think I have everything right). I would not recommend going into full manual mode as it can be VERY discouraging. Keep it simple and have fun!
Comments and concerns with the above are WELCOME! I hope to learn something from this post as well as posts from others. I will add to this as more hints/tips are added.