Tag Archives: aperture

Learn Your Camera With the Flip of a Dial

Get off the Green Box (aka AUTO): These are where you should be.
Creative Commons License photo credit: MoHotta18

This quick little tip is aimed mostly at the dSLR users out there who are still learning the ropes. I know how easy it can be to leave the camera in an “auto mode” so you don’t have to worry about all that technical crap. But the non-auto stuff really isn’t that bad, and it opens up a world of possibilities for you.

[tweetmeme]So this little exercise might be somewhat disappointing on your first go, but it should get you rolling in the right direction. You can do this in a single outing or split it up over multiple days — whatever works for you. And if you don’t feel enlightened after your first try, do it again. Alright, here’s the technique:

  1. SHOOT IN AUTO MODE
    If this is what you’re used to doing, just go ahead and get warmed up. Don’t think about that comfort zone you’re about to step out of, just shoot some photos.
  2. SWITCH TO APERTURE PRIORITY
    When you move to aperture priority mode, you control the f-number and everything else is automated. So now you need to start thinking about depth of field. Look for photo opportunities where you might want to blur the background or have everything in focus. Lower f-numbers equate to lower depth of field and higher f-numbers equate to greater depth of field. Pay attention to your foreground and background subjects, and experiment with different f-numbers on the same shot to see the results. You’ll also need to pay attention to your auto shutter speed chosen by the camera — low f-numbers on a sunny day might max out your shutter speed, and high f-numbers on a cloudy day might result in long exposures.
  3. SWITCH TO SHUTTER PRIORITY
    When you move to shutter priority mode, you control the shutter speed and everything else is automated. Now you need to think about motion blur. Look for opportunities where you might want to blur a fast moving object or freeze everything in the frame. Lower shutter speeds equate to more motion blur and higher shutter speeds equate to freezing action. Pay attention to moving objects, and experiment with panning your camera as you take a shot. You’ll also need to pay attention to your auto aperture chosen by the camera — slow shutter speeds on a sunny day might max out your aperture, while fast shutter speeds on a cloudy day might pin your aperture wide open.
  4. SWITCH TO MANUAL
    If you have a handle on the aperture and shutter priority modes, try switching over to full manual controls. The only difference is that you determine both aperture and shutter speed at the same time (and it’s not as hard as it first seems). Modern dSLR cameras have built-in light meters that tell you if your exposure is correct when shooting manual. That little scale in the viewfinder… that’s your light meter. Move the shutter speed and f-number around and you should see an indicator move across that scale at some point. If your exposure is correct, you should be somewhere around the center of that scale. As you experiment with the manual controls, you’ll probably notice that you prefer to leave the aperture or shutter in a steady place while modifying the other. This will tell you which priority mode you lean toward.
  5. Again, if you’ve never shot the priority modes or the manual mode before, this might be brutal on the first round. You’ll mess up a bunch of shots, you’ll miss shots entirely, and you’ll probably be pissed off. Stick with it though!

    The best way to learn the semi-manual and fully-manual controls is via practice. You can read about this stuff all day long, but that will only take you so far. So get out there and learn your camera!

    Any of you experienced folks have tips for those experimenting with the mode dial? Things to watch out for? Things to try?

Three Ways to Control Depth of Field

My Sunshine

Depth of field (DOF) refers to the amount of a scene in the “sharp” range. Shallow DOF is typically characterized by heavily blurred backgrounds that you might see in outdoor portraits. Deep focus (opposite of shallow DOF) is typically characterized by tack sharp landscapes with no visible blur.

The most widely accepted method for controlling DOF is aperture, or f-number. This is certainly a feasible and convenient way to control DOF, but there are other factors at play. Just like exposure is controlled by three factors (ISO, shutter speed, and aperture), DOF is controlled by three main factors. Let’s take a look at these three factors and how you can use them to your advantage.

[tweetmeme]The examples shown below were taken on a 1.5x crop factor dSLR and the stated focal lengths are actual focal lengths of the lens rather than a full-frame equivalent.

F-NUMBER

The f-number is probably the most widely known and used method of controlling DOF. Most intermediate/advanced cameras have “aperture priority” which allows you you set the f-number. If you’ve toyed with this mode on your camera, you probably found that lower numbers result in a narrow depth of field (blurry background), while higher numbers result in a wide depth of field (everything in focus).

F-NUMBER ⇓ == DOF ⇓

F-NUMBER ⇑ == DOF ⇑

cropped version:

TRY THIS: With a “normal lens” (40-80mm range), find a subject about 5-10 feet away from you and make sure there’s some background object(s) in view behind it. Use your aperture priority and set the lowest f-number you can, and take a shot focused on the main subject. Now stay in the same spot and use the same focal length, but set the highest f-number you can (without bringing your shutter speed too low), and take another shot focused on the main subject. When you compare the two, the main subject should be in focus for both, but you’ll see a difference in the background blur or the amount of focus on objects in the near distance.

SUBJECT DISTANCE

Another way to control depth of field is to change your distance from the subject in focus. If you’ve ever shot macro, you know that the DOF is extremely narrow for 1:1 magnification. This is because you’re so close the subject. On the other hand, if you’ve shot landscapes you’ll know that it doesn’t take much stopping down of the aperture to get everything in the distance nice and sharp. This is because you’re so far from the subject.

DISTANCE ⇓ == DOF ⇓

DISTANCE ⇑ == DOF ⇑

cropped version:

TRY THIS: With a “normal lens” (40-80mm range), set your aperture to a value around f/4 or f/8. Again, find a subject that has some background element in view. Now get as close as your autofocus will allow you and take a shot. Keep the same focal length and the same f-number, but back up about 5-10 feet. Focus on the subject again and take a second shot. When you compare the two, you should see a difference in the depth of field by the amount of background blur.

FOCAL LENGTH

The last factor in your control for DOF is the focal length of the lens you decide to use. Telephoto lenses have a shallow depth of field as compared to their wide angle counterparts. Anybody out there have a sub-20mm lens? It’s pretty hard to get background blur, right? Any super-telephoto shooters out there? Just the opposite.

FOCAL LENGTH ⇓ == DOF ⇑

FOCAL LENGTH ⇑ == DOF ⇓

cropped version:

TRY THIS: Use a zoom lens that reaches from wide angle to telephoto (something like an 18-200, 28-135, etc.) or use two lenses (wide angle and telephoto). Again, find a subject that has some background element in view. Position yourself approximately 5-10 feet from the subject and set your aperture in the low-mid range (f/4-8, but make sure to find something that can be used for both lenses). Take the first shot with the wide angle lens or at the shorter focal length of the zoom lens. Now, hold your position and your f-number, and switch to the telephoto or use the longer focal length of the zoom lens and take the same shot with focus on the same subject. You should see a wider depth of field with the shorter focal length.

PUTTING IT INTO PERSPECTIVE

All this technical stuff is fine and dandy, but how does it translate to real world photography? The answer depends on what you’re shooting with and what you’re shooting at.

If you have a compact camera with no manual controls and you want a shallow DOF (say, for portraits)… zoom in all the way, get as close to your subject as possible (still preserving a decent composition), and take the shot. Also, less light will force the camera to use a smaller f-number and decrease the DOF. If you want a wide DOF (say, for landscapes)… zoom out all the way, get far away from your subject, and take the shot. Also, more light will force the camera to use a higher f-number and increase the DOF.

On the other hand, if you have a dSLR with manual controls and you want a shallow DOF… use aperture priority, set your f-number low (f/2.8-), get close to your subject, and/or use longer lenses. If you want a wide DOF… set your f-number high (f/16+), step back from your subject, and/or use wide lenses.

If you want to do some theoretical calculations on this topic, check out this handy Depth of Field Calculator. You just choose your camera, focal length, f-number, and subject distance. The calculator outputs your DOF, hyperfocal distance, and circle of confusion.

Links from around the web:

Back to Basics – Depth Of Field
Aperture: How It Affects Your Photography & Why You Should Care
Photography 101.5 – Aperture
HowTo: Use The Depth-Of-Field Preview On Your Camera

ANY OTHER TIPS?

How do you prefer to control your DOF? Any SLR shooters out there have a set of numbers that work well for narrow and wide DOF? How about some good examples of DOF in either extreme? We’d love to see ‘em!

Also — any questions on this stuff? I might be jumping over a few concepts, so let me know if anything doesn’t make sense.

Aperture: How It Affects Your Photography & Why You Should Care

The Discerning Photographer posted a good article dealing with aperture from a practical standpoint. This is a subject that tends to be more technical during discussion, so it’s nice to see a different approach.

You’ll still need to have a basic grasp of f-numbers, but the article is really good about explaining the effects of changing aperture. The two main topics beyond the basics are depth of field and exposure, and the article covers these nicely.

What’s Your Favorite F-Number?

In previous polls we’ve discussed topics such as your favorite focal length, camera modes, autofocus modes, exposure modes, and types of cameras. So this time around, we’ll dive into the f-number.

What's Your Favorite F-Number?

The f-number directly affects the depth of field in your shot. It’s also one of the three exposure controls, in conjunction with shutter speed and ISO. Based on our previous polls, I see that most of us are using a dSLR in aperture priority mode, so I’d expect that most of us have a “favorite” number or range of numbers. Personally, I favor F/2.0 on a ~50mm lens on a full frame camera. The DOF isn’t as crazy-shallow as F/1.4, but it still gives a nice amount of separation between background and subject at the distances I’m used to shooting at.

Now, I realize that your choice of f-number will vary depending on focal length, sensor/film format, subject distance, and subject matter. But try to answer the poll with the number that you usually gravitate toward. And feel free to elaborate in the comments!

{democracy:62}

And be sure to check out the last poll on the topic of “Why Are We So Compelled?” Lots of good thoughtful discussion there with 27 comments (and a few of them are quite lengthy)! As always, I appreciate the participation in these polls and discussions.

Link Roundup 08-09-2008

Great stuff around the web this week!

PROJECTS

  • Just A Second
    Neil Creek
    Neil is starting up a new project having to do with semi-long exposures. He’s looking for us to take 1 second exposure photos.
  • September Challenge Update
    PhotoChallenge.org
    Trevor gives us more information on the upcoming September Challenge having to do with portraits. He’s outlined a specific theme/subject for each week during the month.

READING MATERIAL

Link Roundup 12-29-2007

Before we get to the list, be sure to check out my super-cool guest-post on “Going with the Grain” over at ADIDAP (we swapped posts for Christmas). I’ve always liked grainy photos, so I put together a little information on the subject and picked out some CC photos to help make my point.