This past weekend, we went out of town on a family visit. During the night, as I tried to sleep (and as I constantly removed my daughter's feet from my ribs), I got to thinking about depth of field and how I was going to write this next part of the series. And it dawned on me - this is going to have to be a two or three part post. There are several great ways to show depth of field - macro photography is one of them. When people say "macro" in the photography world, they are referring to taking a close up picture of something that is relatively small and making it look large. It is a very detailed image. One time, I took a macro image of a grasshopper, and you could see it's hairs! (And that was a pretty amazing task for me since I hate bugs!)
I looked around this afternoon for something to shoot for this post, and I found something fun and colorful - something many moms of toddlers have handy - Fruit Loops! I got out a white towel and set up on my love seat. Here's the set-up:
For whatever reason, depth of field was a tough concept for me to grasp. I can still remember the light bulb moment as if it happened yesterday - somehow everything just clicked together and it all made sense. If you are having trouble with this concept as well, I hope my fruit loops can help.
In the left hand picture, the camera was focused on the orange and yellow fruit loops that are crystal clear. You can see that everything in front of and behind them are blurry. That shows a shallow depth of field. The picture on the right was focused a little bit in front of the same point, but you can see that many more fruit loops are clear. That is a much wider depth of field than the other picture. Think of whatever object your camera is focused on - however much more space in front of and behind the object that is also in focus is your depth of field. The things that affect depth of field are your aperture (or f-stop) setting and the distances between you and the subject, you and the background, and the subject and the background. Shallow depth of fields tend to isolate your subject(s) - in the picture of the left, my eyes are automatically drawn to the two fruit loops that are clear. I would describe the picture on the right as being more broad because so much more is in focus. Just one or two fruit loops don't stand out to me - I just see a lot of cereal!
In the above example, the left hand image was taken at f/2.2, which is a much larger lens opening (aperture) than f/8, which is the aperture setting that was used on the right. As a matter of fact, there is such a difference in the sizes of the opening that I had to use my flash for the one of the right, but not for the one of the left (since aperture also affects your exposure - but, more on that in another post). This image clearly illustrates that the larger your lens opening is, the more shallow your depth of field is. Which image looks more interesting to you? I like the one on the left better. But, lets say you were shooting these fruit loops for a box of cereal. Maybe the manufacturer would want all of the loops to be in focus. In that case, the image on the right would be more desirable. You, the photographer, would have to have the knowledge of how to make that happen.
Let's try using the f/8 setting, but moving a subject away from the background:
Here, I have stacked four loops and moved them away from a pile. You can see that my stack is clearer and more in focus than the pile, and so it is more isolated. But, let's see what happens if I take the same picture with the f/2.2 setting:
I know it looks like I moved the stack further away, but I didn't! My depth of field just got so much more shallow that the stack is even more isolated than before.
Let's go back to the f/8 setting. This time, I'm going to make another stack of fruit loops, but I'm going to move it even further from the pile:
This is a great example of distance making a difference. This stack is much further from the pile, and you can see that the pile is much more out of focus than the stack, despite our smaller aperture. This is a great illustration that if you were in a situation where you had to use a smaller aperture, but you wanted to isolate your subject, it is still possible to do it by moving your subject further away from the background.
Just for kicks, let's see what this image would look like with a f/2.2 setting:
Quite a difference!
In all of these shots, I was about the same distance from the objects that I was focusing on. I simply adjusted my aperture setting and the distance from the subject and the background. In my next "Getting to Know Your Camera" post, I will apply what we've discussed here to other types of photography, including people. We will be able to expand on moving away from the subject and other ways to lengthen or shorten your depth of field.
** If you are practicing along and you have not yet been shooting in manual mode, you may want to change your mode to the aperture priority mode. This way, you can change your f-setting, but the camera will take care of the shutter speed for you. When you use the smaller apertures, your camera may adjust your shutter speed much slower to allow more light into the camera. You will have to compensate this by either using a flash or using a tripod (to avoid motion blur from you holding the camera). Sometimes with macro photography, pop up flashes are ineffective because the lens is in the way of the light that the flash is putting out. You will have to play with your camera and see how to overcome these obstacles if they occur.
Guest blogger is Corrine Corbett of Timeless Blessings, is a stay at home mom and photographer wielding a Sony Alpha 500. As a guest blogger she hopes to teach you all things that will take the frustration out of photography and leave you more and more satisfied with your art. Her current eye candy comes from Morgan Kervin, Denise McCabe and Isabelle LaFrance.
"I have learned so much from other photog bloggers out there.
I'm really looking forward to the opportunity to pay it forward with anything that I learn! :)"