Shutter Speed

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 1/6000^th 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). 1/6000^th 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 1/60^th to 1/3200^th 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 1/60^th 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. 1/2500^th of a second.

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

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

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

Using Autofocus

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

Apologies for Being Absent

It’s been pretty obvious that I’ve been neglecting my blog. I’m going to make an effort to update it more regularly. Just because my entries stopped, didn’t mean my interest in photography has waned. I’ve still been shooting and learned a couple new things along the way. I’d like to ask a favor of my readers, please make comments. I’d love to hear your feedback on what I’m writing.

Buying a Digital Camera

If you are like me, then buying a digital camera is an overwhelming process. There are literally hundreds of cameras on the market and dozens of places to buy. Prices can range from under a hundred dollars to a several thousand. I’m not an expert on camera selection, but here is the thought process and learning I had when I selected my camera.

I’ve broken the digital camera market down into four “styles” of cameras:

1. Point and shoot compact cameras
2. Consumer model cameras with advanced settings
3. Consumer style D-SLR cameras
4. Pro level D-SLR’s

Each camera has a distinct purpose and situation that they are best suited for. The best advice I have is to choose the one that makes the most sense for your photographic needs, but that also fits in your budget. Buying the most expensive camera isn’t going to make you a better photographer. Knowing how to use the camera you have is what is most important. As the week goes on, I’ll create an entry for each segment of camera and walk you through the defining characteristics of each. I’ll also share what I bought, and why.

For now, a couple resources to check out are:

• DP Review (www.dpreview.com): Checkout the buying guide and camera database
• Consumer Reports (www.consumerreports.org): Good for reliability and feature comparison, but the site charges to see everything
• CNet Digital Cameras (www.cnet.com): This link takes you to the digital camera section. There are a lot of good reviews here.

Just a note here, I’m exclusively talking about digital cameras. If you are interested in traditional film I don’t really have any advice for you.