question on av and tv settings?

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Permalink Reply by Elisab on March 29, 2009 at 7:58pm

That is a lot of information you are wanting. The book may be complicated, but take your time with it and study what they are saying.

I can help you out a little. When you turn to Tv, you choose your own shutter speed and the camera will choose the aperture or f/# to match the shutter speed for the lighting. When you turn to Av, you choose the f/# and the camera chooses the shutter speed to match your aperture for the lighting.

A faster shutter spped in Tv will stop motion in the photo for sports. A slower shutter speed will show motion for waterfalls.

The f/# that has the larger opening is the smaller number. f/2 has a larger opening that f/11. If you want your subject to stand out. such as a portrait or a flower, you use the larger f/# (say f/2) and the background of the shot will be blurred. If you want the whole shot in focus, such as landscapes, use a smaller f/# (say f/11 or higher).

I don't know why they did that with the f/#s. It seems like it is backwards, but that is how they did it. Keep going over the info in the book and it will start to sink in.

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Permalink Reply by Brian Leng on March 30, 2009 at 9:08am

The reasons for the use of fractions is because they are all one F stop more light. But newer camera are in whole numbers.

Tv is the speed of your shutter and Av is for your aperture opening. Just remember what T means and what A means. Nikon just has S & A.

Try and learn the four basic digital camera set up:

1. ISO (sensitivity of the CCD chip & and with film, the sensitivity of the film. Faster ISO has less quality then lower ISOs)

2. Shutter Speed

3. Aperture Opening
(The combination of the above three needs to be just right to give you a normal exposure)

4. Quality & file type (Large Jpegs have the most resolution meaning they have more pixels but make larger files)
Small Jpegs have less pixels therefore having less quality but more images. I recommend using the LARGE JPEG because you never know what you might want to use that photo for even though it makes larger files giving you less frames.

Because digital cameras have many more camera controls then film cameras, people are over come by the choices they need to make so they opt to use the camera on automatic. But when you have the camera set on automatic, the camera is in control rather then you controlling the camera.

My suggestions are to find a beginning digital photography workshop at a local community college or from a camera store.

Play with your camera as much as possible even if you don’t take any photos.
The camera manuals are a different language (even though they are written in english) so don’t feel bad that you don’t understand what is written. Many people don’t understand either.

Remember this: Being a photographer is like being an athlete. If he or she doesn’t train everyday, on race day they will loss the race because they did not practice everyday. Those that are truly passionate about photography do not give up. They keep on learning new techniques.

Practice, practice, practice. It was more costly with film, but then again, film cameras were a lot simpler. Good luck.

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Permalink Reply by Matt Needham on April 8, 2009 at 9:23am

A stop is the term photographers use when measuring light. A stop is not a specific amount of light, but rather half or twice as much light. If I increase the exposure by one stop I am doubling the amount of light that reaches the film/sensor. If I decrease by a stop I am halving the amount of light. Here are the standard lists of aperture, shutter, and ISO in 1 stop increments.

shutter: more time (more light)....1 sec, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000....less time (less light)

aperture: bigger hole (more light)....f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, f/90....smaller hole (less light)

ISO: less sensitive (needs more light)....25, 50, 100, 200, 400, 800, 1600, 3200, 6400....more sensitive (needs less light)

Notice that for shutter and ISO the number doubles or halves for each stop (a doubling or halving of the light). Aperture is a little trickier; when the f/# is doubled or halved it's 2 stops. Some of the numbers are rounded so the math isn't always perfect: twice as fast as 1/60th should be 1/120th, but most cameras set it to 1/125th, and so on.

But the good news is you really don't need to memorize these numbers/lists because most cameras keep track of them for you. You just need to know what increment your aperture, shutter, and ISO dial/buttons/clicker/ring/whatever operates in. Most cameras adjust in 1/3, 1/2, or 1 stop increments. If your aperture dial adjusts in 1/2 stop increments then 2 clicks is a stop. They may not all operate in the same increments so read your camera manual.

Here's a common analogy: exposure as filling a bucket of water at a faucet.

The bucket is the film or sensor. Water is light. The faucet is the camera controls aperture and shutter. Normal exposure is filling the bucket to the rim without under filling or going over.

The bucket size is ISO. An ISO 100 bucket requires twice as much water to fill as an ISO 200 bucket, four times as much water as an ISO 400 bucket, and 1/2 as much water than an ISO 50 bucket.

How much you open the faucet is aperture, and how long you let the faucet run is shutter speed.

To fill the bucket you could open the faucet full blast for a short time, or a trickle for a long time, or anywhere in between. The key to success is understanding that if you add more water you need to decrease the time it's flowing. In photography it's the same. If you open the aperture larger (smaller f/#) then you need to decrease the amount of time the shutter is open. This relationship is called reciprocity.

Aperture controls depth of field (DOF). DOF is how much of the subject/scene is in focus/blurred in front and back of the focus distance (for most cameras and lenses). Typically portraits have shallow DOF and landscapes deep DOF.

Shutter controls the rendering of motion. High shutter speeds freeze motion. Slow shutter speeds allow for blur.

So both settings can be used to control/create/eliminate blur in different ways.

In some situations you can set aperture and shutter exactly how you want them, but more often you'll have to choose which is more important, and/or make a compromise between the two.

In Av you get to set the aperture, controlling DOF, and then the camera will set the shutter to whatever the meter says will make a normal exposure. With Tv you set the shutter, and the camera sets the aperture. It's the same as running the camera in manual if you are setting one, and then zeroing/balancing out the meter with the other.

Setting a small aperture (big f/#) in Av is similar to landscape mode. Setting a large aperture (small f/#) in Av is like portrait mode. A fast shutter in Tv is like sports/action mode, and a slow shutter in Tv would be like panning mode (not all cameras have that one).

I almost never use Tv. With my typical subject matter my primary concern is DOF 99.99% of the time, so I'm always in Av or manual.

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