Depth of Field

Depth of field or DOF, is a term used to specify the area of a scene that is in focus. A “shallow depth of field” has the subject sharp in focus, but the rest of the foreground and background is out of focus. The background and foreground appear soft. This is a great technique for getting your subject to stand out from the background. Take a look at this picture. You can see how I’ve made the background flowers out of focus so that subject flower stands out more.

Here is an example of where I didn’t do a great job separating the subject from background. I wanted just the first tulip to be the center of focus, but all the background is in focus too, and it’s distracting:

There are three things the affect the size of your Depth of Field: Focal length, aperture, and distance from the subject. I will go into the technique more later, but to summarize:

• Focal Length: The more zoom, the shallower the DOF
• Aperture: The wider the aperture (small F-Number) , the shallower the DOF
• Distance from subject: the closer to the subject, shallower the DOF.

The Basics - Aperture

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

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

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

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.

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.

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.

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

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

Photography: It’s all about Light

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

Overexposure

Correct Exposure

Adobe Photoshop Lightroom: A great way to organize images.

Full Disclosure: I work for Adobe, so I may be biased… however, I don’t recommend anything I don’t use myself.

I’ve been using Photoshop Lightroom for over a year now, and I still love it. Prior to finding Lightroom, I’d been taking digital pictures for about 8 years, and had never come up with a system that I liked for storing and cataloging images. I’d tried using Windows Explorer file system, iPhoto, and up until last year, I was pretty happy with Picasa, but Lightroom has blown them all away.

There are several functions in Lightroom beyond just organizing (all of which I love), but for just remembering what/where/when you took a picture, the Library module in Lightroom is awesome. Right from importing your photos from you camera, it keeps everything in one place. For safety, it automatically makes copies of your pictures for auto-backup. (having lost a lot of data, I can’t stress this enough).

I’m gonna spend a lot of time talking about Lightroom in this blog as I learn more. It is super powerful and has tons of features that’ll probably take me months to learn, however if you use it as nothing more than just an organizer, you’ll still be happy.

A couple things to point out: Lightroom 2 is available for a free 30-day trial from Adobe.

Also, to get started using the software, I highly recommend the Lynda.com training It’s done by Chris Orwig and really helped get me going with the software.

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 point and shoot compact camera

If a camera can fit in your pocket, chances are, it is a point and shoot. These cameras are great for a night out on the town, or anytime you want to take pictures, but don’t want to lug around a heavy camera. These cameras are generally the least expensive and range in price from under a hundred to around $400. Most point and shoots purchased in the last couple years take pretty great pictures. So, you are probably asking yourself, if these cameras are the smallest and lowest price, why don’t I just stop here, why do I need anything more?

Control, control, control! As we start to get into more advanced features of the camera, it becomes important to be able to change different ‘setting’ that the camera uses to capture the image. The two biggest ones are shutter speed and aperture (don’t worry if you don’t know what those are right now, I’ll be covering them in later entries).

If you look at the controls on the point and shoot cameras,

you’ll notice that they only have an auto setting and a couple pre-sets.


They don’t allow you to individually change the shutter speed or aperture. The camera relies on its internal computer and sensors to make a decision about how these things should be set. It usually gets pretty close, but you can’t do the fine-tuning that makes your images look really fantastic. There isn’t an image sensor or camera processor that can make decisions as well as the human eye… at least not yet.

Also, interchangeable lenses! The point and shoots come with one lens that is attached to the camera. That is the only lens that you will be able to use. If you want to shoot close up pictures, wide angle, or super zoomed pictures, you are out of luck. Point and shoot cameras do have the ability to zoom, and usually say something like “3x optical zoom”. This means that you can make an image 3 times larger. However, ever other camera uses a measure of mm to denote the camera’s zoom. A typical zoom range for a point and shot with “3.8x optical zoom“ is from 28-105mm, but that is hard to gauge, because they have different starting points to do 3x. I’ll get into more detail about what those numbers mean later, but they are useful for comparison.

Also, remember that DIGITAL ZOOM IS A SCAM!!! More on this tomorrow.

Personally, I have a point and shoot that I carry around with me when I want to take some snapshots. It’s a Canon SD850IS.

I bought it two years ago and carry it around when I don’t want to deal with the bigger cameras.


Examples: Canon SD970IS, Nikon Coolpix S230, Sony Cyber-shot DSC-G3

Thanks to DPReview.com for the camera images above.

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.

www.jordanldavis.com is now live

Success!!! I was able to map the domain I bought and point my blogger account to that URL. www.jordanldavis.com is now live and running.

I'm starting this blog to chronicle my experience learning to become a photographer (or at least learn how to use my camera). I've been lucky enough to have the opportunity to enroll in a photography course at the Academy of Art University in San Francisco, and wanted to share that knowledge with friends and families. I'll try to distill each lesson down and post it online so that others can benefit from what I'm learning. It will start out pretty basic with camera instructions, and hopefully get more and more advanced ans my knowledge and skills improve.

I'll also try to post samples of my work and share some of the feedback I get from class reviews. Please feel free to leave me comments, I'll try to reply to them.