Archive for the ‘settings’ category

The Basics – Aperture

September 14th, 2009

Aperture is one of those photography terms that intimated me at first. It sounds quite technical, and even the units, F-Numbers, don’t make a lot of sense. Changing your aperture is a very powerful tool to a photographer, and there are many reasons why you’d chose a certain value, however, it again all comes down to light. In combination with shutter speed, aperture controls the amount of light hitting your image sensor. The more light, the brighter your image, the less light, the darker your image.

Technically, aperture refers to the size of the opening in the lens. Take a look at the example below. The top image is a wide or large aperture (lots of light), while the bottom image is a smaller aperture (just a small amount of light).

The other hard to grasp part of aperture is the numbering system. Aperture uses F-numbers or F-stops. It seems counter intuitive to me, however, the smaller the number, the larger the opening. So in the pictures above, the top lens might have an aperture of f/2 while the lower image has f/16. A trick I use to help me remember how F-numbers work was given to me by my photography professor… “think about inflating a cartoon bike tire. If you inflate it with a lot of pressure, the hole in the middle will get smaller” More pressure = tighter aperture = higher F-Number. Not sure if that helps you, but it works for me.

These images are all shot keeping the shutter speed constant and just adjusting aperture (which will cause them to be under/over exposed).

Overexposed with wide aperture: 1/10 sec, f/5.6

Over exp Wide Ap

Proper Exposure with medium aperture: 1/10 sec, f/11

Expose Med Ap

Underexposed with small aperture (big f-number): 1/10 sec, f/22

Under expose small Ap

Aperture also has another effect on your images beyond how bright or dark your image is. After all, why would you need 2 ways to control this, shutter speed and aperture. What aperture does is also change the amount of your image that is in focus. This is referred to as the depth of field. I’ll cover depth of field in a later post, however, to illustrate the effects, take a look at the three images I’ve shot below.

Exposed properly, but with different aperture/shutter speed combinations, so you can see the depth of field effects.

½ sec, f /22 (all 3 quarters are in focus) – Slow shutter speed because aperture is small. This lets in enough light.

Big DOF

1/10 sec, f/11 (Center quarter is in focus, but back is out of focus, and most of front is out of focus) – Faster shutter speed because less light is needed when aperture is larger.

Med DOF

1/40 sec. f/5.6 (center quarter is the only one that is in focus) – Even faster shutter speed because aperture is all the way open.

Small DOF

This was another resource that I found helpful if you want to learn more:

http://www.photoaficionado.com/situationroom/aperture.html

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Posted in Aperture, Blog, Shutter Speed, photography

Shutter Speed

August 29th, 2009

Shutter speed refers to the amount of time that your image sensor is exposed to light. Refer back to my earlier post on the anatomy of a DSLR, and you’ll see that the shutter is in front of the image sensor. So, the “faster” your shutter speed, the less time light (which is the image) is hitting the image. “Slower” shutter speeds, means that the image sensor is exposed for a longer period of time.

Shutters are normally very fast… fractions of a second. That’s all the light you need to make a photo. Shutter speeds range from about 1/6000th of a second to about 8 seconds. The light you have available to take a picture, determines how you set your shutter speed. 8 seconds, (denoted 8” on the back of the camera) would be used for incredibly low light (ie, Taking pictures of the stars). 1/6000th of a second (denoted 6000 on the back of the camera) would be used for taking pictures when there is a lot of light available (ie, middle of the day, pointed at the sun).

Under normal, daytime conditions, I shoot in the range of 1/60th to 1/3200th of a second. I generally try to use the fastest speed that the light will allow. The faster the shutter, the less chance I will cause the image to be blurry by shaking the camera. This type of blur is called “motion blur”, and causes everything in your pictures to appear out of focus. If I’m going to hand-hold my camera (not use a tripod), I won’t set it below 1/60th of a second. It is next to impossible to hold still enough at this speed.

Take a look at the three photos below to see the effects of shutter speed. I’ve kept all the variables the same (Subject, time of day, aperture, white balance, iso camera location) except shutter speed.

This image has the “fastest” shutter speed. 1/2500th of a second.

Sunglasses 1/2500 sec f/5.3

This image is a little slower. 1/2500th of a second.

Sunglasses 1/1250 sec f/5.3

This is the slowest image 1/800th of a second.

Sunglasses 1/800 sec f/5.3

Notice that the photos get darker the faster the shutter speed is. This is because less light is hitting the sensor. 1/2500th of a second’s worth of light vs. 1/800th of a second.

So, when shooting in the manual mode, I set the aperture, and then adjust the shutter speed until the image is exposed properly. The camera will also do this automatically for you if you shoot in Aperture Priority Mode.

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Posted in Blog, Shutter Speed, camera, settings

Photography: It’s all about Light

August 21st, 2009

When thinking about photography, it all really comes down to light. That’s what goes onto the cameras sensor, and that is what makes an image. Exposing the perfect picture comes down to your ability to control the light that comes into the camera. There are three settings on your camera that really control the light coming in.

  1. 1. Aperture: The size of the “hole” light comes through to your sensor
  2. 2. Shutter Speed: The amount of time light is being captured by the sensor
  3. 3. ISO: The sensitivity of your sensor.

I’ll cover each of these in separate blog posts. But being able to control these three settings are what will enable you to capture that perfect shot. These all three come together to become the “exposure” of the picture. You’ve probably heard the term “overexposed” or “underexposed” before. By changing aperture, shutter speed, and ISO, you can control the amount of light in the picture and get the perfect exposure.

Below are three examples of exposure:

Underexposure

Underexposed

Overexposure

Overexposed
Correct Exposure
Exposed

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Posted in Aperture, Exposure, Lightroom, Shutter Speed, iso, photography

Using Autofocus

August 19th, 2009

The ability for a camera to automatically focus is awesome. The fact that your camera can look at an object, determine if it is sharp enough, and change the focus blows me away every time. When I first got my DSLR cameras, one thing I’ve noticed is that it was unpredictable on what it would focus on. I’d look through the viewfinder, and want to focus on the person in my shot, and it would focus on some leaf in the foreground. Or it would focus on the closest person instead of the person in the middle. Turns out, my Nikon has some settings for the focus mode that I didn’t know about. The factory had it set to focus on the closest object, regardless of where it was. This wasn’t working for me, because I didn’t always want the closest object in focus.

What I’ve done to simplify my life and make my autofocus only focus on what is in the direct center of my viewfinder. Looking through my Nikon, (D40) I have an indicator that looks like:

These boxes are the focus area indicators. I’ve changed the settings in the back menu (check your manual to see what menu), so that only the center square is put in focus.

I know what you are saying, “what if I don’t want the center to be in focus, what if I want something on the right or left to be in focus. I that case you put the item you want to focus on in the center brackets, press the shutter button half way down and then re-compose you image. This blog talks about some of the other features of autofocusing that I won’t rewrite here: http://www.kenrockwell.com/nikon/d80/af-settings.htm

I also noticed that sometimes the camera wouldn’t focus, it just kept searching, and never finds a focus distance. The autofocus in your camera uses lines of contrast to focus. So you need to look at the edge of an object to get the camera to focus. It you are trying to focus on something all the same color, the camera won’t know how to make it sharp

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Posted in Nikon, camera, focus, settings

Becoming Master of Your Domain: Camera Modes

April 9th, 2009

One of the first things that new camera owners start to play with on their DSLR is the little Mode Dial on the top of the camera:

Nikon

inhandNikon

Canon
inhandCanon

Everyone is always tempted to just put it on Auto, and leave it, but here’s what these different Mode Dial symbols mean (I’m going to focus on Nikon and Canon):

Nikon Canon
P P Program Mode: this is almost automatic, but allows you to change a couple settings like ISO and white balance. It is a way to override some of the decisions your camera’s auto sensor is making.
S Tv Shutter Priority: You chose the shutter speed, and the camera selects an appropriate aperture value. This is a semi-auto mode, but it is great for getting a specific effect.

For example, it you want to get a crystal clear picture of a track runner, you need a fast shutter speed to stop the runner. Otherwise you will get a blur. In this mode, you set the shutter speed fast, and the camera picks the appropriate aperture to get enough light.
A Av Aperture Priority: You chose the aperture value, and the camera selects an appropriate shutter speed. This is a semi-auto mode, but it is great for getting a specific effect.

For example, it you want to take a “selective focus” picture of a flower (flower in focus, background out of focus) you need a wide aperture (low f-number). This will put the flower in crisp focus, and have the background all out of focus. The camera then compensates with the correct shutter speed to let the right amount of light in.
M M Manual: Allows everything to be set by the user. I shoot most of the time in this mode.
Auto Green Box (Auto) Auto: “photography for dummies”. This setting uses the camera’s image sensor to decide all settings. It usually gets close, but I’ve found that I can usually do a better job controlling brightness, white balance, and shooting style using the Auto Mode
Icon Icon Scene Select: the second half of the camera mode dial has little pictures on it that are meant to specify a shooting scenario. They basically change some of the pre-set features for each scene type. I find them useless.

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Posted in Canon, Mode Dial, Nikon, camera

Consumer Model Cameras with Advanced Settings

March 19th, 2009

These cameras are generally larger and more expensive than the point and shoot cameras. The reason to use the advanced cameras over a point and shoot is they allow the photographer to change some key settings:
• Aperture
• Shutter Speed
• White balance

As you become more advanced with your photography, you will begin to use these settings to get the desired effects from lighting, focus, and color. The Consumer Models let you change these settings (although they are buried in the menus of the camera). A great example is the Canon PowerShot A720IS (http://www.dpreview.com/reviews/canona720is/). It allows the user to shoot in Manual mode (set both aperture and shutter speed) to have more control over the images.

The difference between these cameras and their D-SLR counterparts are interchangeable lenses, and on-camera controls for adjusting aperture and shutter speed. If you are shooting a lot of pictures in changing light conditions, it is pretty annoying to have to keep navigating through menus to update these settings.

All in all, these are great for cost conscious photographers who want to learn photography, but don’t want to invest in an expensive D-SLR.

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Posted in Aperture, Canon, Shutter Speed

Digital Zoom is a Scam

March 6th, 2009

Cameras advertise that they have 15x digital zoom, which means absolutely nothing! All digital zoom does is enable the camera to blow up the picture and crop the edges. You can do the same using photo editing software on your computer or even through some print providers. (I’ll also cover this later). They say this is a big feature, and even advertise the camera as having tons of zoom. Don’t fall for it. Let me show you the difference between optical zoom and digital zoom.

Here are some examples of optical zoom I stood in the same place and took pictures of this water bottle.

This image with 1x optical zoom:

IMG_0693

This image is 3x optical zoom:

IMG_0692

This is “real” zoom. You can notice that with the 3x optical zoom, the image is still sharp and clean. This is because it contains the same number of pixels as the 1x optical zoom.

Now, this is an example of digital digital zoom. I used the digital zoom on the camera and went to 15x:

IMG_0694

You can see in the image, that it has lost some of its sharpness. Look under the red band of the label and you will see some jagged edges, as well as the lettering in crystal. The interesting thing is that I can produce the exact same image with the exact same sharpness by just using a crop tool on my desktop:

IMG_0692

This picture just a crop of the picture above from 3x OPTICAL zoom. Notice how is just as sharp as the 15x digital zoom.

Please, don’t be fooled by digital zoom!

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Posted in Zoom, camera, crop