In the previous post I wrote an extensive guide on exposure in (Lego) photography. One of the aspects discussed was the exposure-triangle. As you know, one of the three camera settings that give you control over exposure is the aperture. The other setting is shutter-speed (and ISO for the brightness of your photo).

In this post, I will cover everything you need to know about aperture for your (toy) photography. Aperture-settings affects many different elements of an image. Most importantly it can add dimension to your scene by blurring the back- and foreground, while altering the brightness of your photos. There is a lot of ground to cover, so we better get going.

What is aperture?

The look of an aperture.
Figure 1: The look of an aperture.

Aperture is the opening in a lens through which light passes to enter the camera body. The aperture consists of several metal ‘blades’ that together form a circular opening. You can move these blades thus changing the size of this opening.  So, essentially, aperture is like a human eye’s “pupil” for your camera, which can open and close to change the amount of light that passes through. Ultimately, by shrinking or enlarging the aperture size you’ll allow more or less light to reach your camera sensor, thus brightening or darkening you photo. Figure 1 shows you what an aperture looks like.

Size of Aperture: Large vs Small Aperture

f-numbers and aperture-size

To be able to work with all the different aperture-sizes the ‘*f-number*’ has been agreed upon as standard for measuring the size of the aperture. So, whenever you see an aperture-size value, the letter f is added, like, for example, f/2.8 or f/4. Sometimes the ‘/‘ is omitted and f-numbers are written like f2.8 or f4.

Confusingly to many beginning photographers small f-numbers are large apertures and large f-numbers are small apertures. For example f/4 is a large aperture and f/22 is a small aperture.

However, the actual f-number is calculated by dividing the focal length of your lens by the diameter of the aperture. That means aperture is a fraction! Thus, f/4 = 1/4th and f/22 = 1/22th. And clearly, 1/22th is much smaller than 1/4th.  Regarding the f-number as fractions suddenly clarifies the relationship between f-number and size of the aperture.

f-stops and exposure

Another confusing fact is that when the diameter of a circle doubles, the surface of the opening enlarges by the square of two. So a change of aperture from f/8 to f/4 does not double the exposure, but multiplies it by eight!

A change that either doubles of halves the amount of light reaching the sensor is named a stop. Consequently, the most common f-numbers /do/ double or halve the exposure value (EV) for each consecutive f-number. These are called the *f-stops*. They are (from large to small aperture): f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22 and f/32. Figure 2 shows you what different apertures look like at different f-stops.

Common aperture-sizes ultimate guide aperture
Figure 2: Common aperture-sizes

Effects of changing aperture-settings

Changing your aperture value has an effect on the depth of field and brightness of your photo. In short; The higher your aperture value, the busier/sharper the back- (and fore)ground will be and the darker your photo will be. The lower your aperture value, the blurrier the back- (and fore)ground will be, whilst the lighter your photo will be.

Effect of changing aperture-settings: Exposure

When you change the aperture-size, you alter the overall amount of light that reaches your camera sensor, and therefore the brightness of your photo. A large aperture (a small f-number) will pass a lot of light, resulting in a brighter photograph. A small aperture (a large f-number) results in the opposite, a darker photo. Figure 3 shows you what happens to exposure when you change the aperture from f/2.8 to f/32.

Example aperture exposure Lego photography
Figure 3: The effect of aperture on exposure.

Effect of changing aperture-settings: Depth of field

Changing aperture-size also changes the depth of field (DOF) of your photo. Essentially, only the object you focus upon (the focal point) is 100% sharp. However in front of and behind the focal point there is a range where the sharpness of the image is generally accepted as being nearly 100% sharp. This range is named the depth of field. Of the total DOF 1/3th is in front of the focal point and 2/3th is behind it. In macro-photography and close-ups this distribution is more like 50/50. Figure 4 shows you the basics of depth of field.

Depth of field - DOF chart - ultimate guide aperture
Figure 4: The basics of depth of field

So, depth of field is the portion of your photograph that is sharp from front to back. Some photos have a “thin” or “shallow” depth of field, where the back- (and fore)ground is completely out of focus/ blurred. Other photos have a “large” or “deep” depth of field, where most of the back- and foreground are sharp.

Figure 5 shows you a comparison of the effect on DOF between aperture sizes. The EV is equal in all images because I adjusted the shutter-speed (remember the exposure-triangle!)

example aperture depth of field lego photography
Figure 5: The effect of aperture on depth of field.

What more affects depth of field?

If you aks a (beginning) photographer, what influences the DOF, most will answer the aperture. Of course that’s not wrong, but there are three other factors that come into play; the focal length of your lens, the sensor-size and the distance to the object you are photographing. In short:

  • Object distance: The closer your object, the shallower the DOF and vice versa.
  • Focal length:  Focal Length refers to the capability of a lens to magnify the image of a distant subject. DOF gets shallower as the focal length increases, and vice versa.
  • Sensor-size: The larger the camera-sensor, the shallower the DOF and vice versa. So, for example, a full-frame camera will have a shallower DOF compared to a compact camera.

Controlling depth of field

In summary:

To increase your DOF (deep DOF)

  • Narrow your aperture-size (larger f-number)
  • Move farther from the subject
  • Shorten focal length of your lens
  • Use a camera with a smaller sensor

To decrease your DOF (shallow DOF)

  • Widen your aperture-size (smaller f-number)
  • Move closer to the subject
  • Lengthen focal length of your lens
  • Use a camera with a larger sensor

Effect of changing aperture-settings: Bokeh

Bokeh (pronounce like ‘bouquet’) comes from the Japanese word meaning blur. It is the way that out of focus areas beyond the depth of field are rendered.  In other words, the bokeh refers to the quality of the blur in the out of focus areas.  Photographers often describe a photo with good bokeh as having a  ‘creamy’ out of focus area.

The best results are usually obtained by using a lens with an aperture consisting of many blades (9 being typical). These blades should have a rounded edge to create a near spherical opening for the best Bokeh (figure). Eventually, bokeh is a property of a lens rather than a camera. Figure 6 shows the relationship between quality of bokeh and aperture.

the relationship between quality of bokeh and aperture
Figure 6: the relationship between quality of bokeh and aperture.

Bokeh also refers to the pleasing circle shapes caused by the shape of the lens aperture. This effect is usually created when shooting with your aperture wide open, such as f/2.8.  However, bokeh can also be created with smaller aperture-sizes as long as the background is distant enough from the in focus subject! The edges of these highlights should also be soft and not haloed or hard-edged to be perceived as pleasing. Figure 7 shows you an example of how, even not that good a bokeh, can influence the mood of your Lego photo.

Bokeh lego toy photography
Figure 7: An example of Bokeh

Effect of changing aperture-settings: Starburst effect

When shooting into the sun or other light sources, you may notice that some of your photos show a more intense light with clearly defined light rays. This is known as a “starburst” effect.

This effect has its origin in the aperture size and shape. In short; imperfections in the circle formed by the aperture blades create lightrays. Since the number of imperfections are dependent on the number of blades of your aperture, the blade-count of your aperture will tell you how many rays of light you will get in your photo. When you have an even number of blades you will get the same amount of rays. And when you have an odd number of blades you will get double the number of rays as you have blades. Figure 8 shows you an example of starbursts.

Starburst effect
Figure 8: An example of the starburst effect (Pentax forums)

The smaller the aperture-size, the more the more “starburst” you’ll see in your photo. So, to create this effect you need an aperture-size of f/11 or smaller, I would recommend maximally f/16.

Lastly, remember that the lower the focal length of the lens, the smaller the physical opening of the aperture, so the more you zoom out, the more “starburst”.

How to pick your aperture in Lego photography

So, now that you know a bit about the background of aperture, how do you know what aperture-size to use for your Lego photos?

Lens limitations

First look at the specifications of your lens, it says what the maximum and minimum apertures are because every lens has a limit on how large or how small the aperture-size can get. The maximum aperture-size (smallest available f-stop) is the most important value since it tells you how much light the lens can capture at its maximum. If you’re using a zoom-lens, also look if the maximum aperture-size changes dependent on the focal length (zoom) you’ll be using.

Brightness of the scene

Usually if you’re shooting a darker scene, you may want to use large apertures like f/2.8 to capture a photo of the proper brightness. However, many Lego-scenes are pretty static, especially if you’re using a tri-pod. So if there are no moving objects in the scene, simply change the aperture-size dependent on the DOF you would like to have in your picture and adjust the shutter-speed (and/ or ISO) to get the brightness of your photo you’d like.

Lastly, if there is a chance of motion blur try to keep your aperture-size to a value that enables a shutter speed (possibly combined with a decent ISO-value) that is still fast enough to capture a subject without motion blur.

Depth of field

Depth of field does not only make your photo look different, it also has clear effects on how everything in the photographed scene is perceived.

First; the viewer’s eye will always go to the area within a photo that’s in focus. It will more or less ignore parts that are out of focus. This effect is named *selective focus*. To accomplish this effect mostly a large aperture-size (small f-stop) is used.  It is very useful to show the viewer what you believe to be the most important part of the scene. Take another look at figure 5. At f/2.8 your eye is immediately drawn Dwaas while at f/32 you will probably be confused on what is the most important part of the image.

For example; if you have a dialogue in a scene of your Lego comic you can put selective focus on the person most important. This could be the person speaking, however, maybe you would want the person speaking blurry and put the selective focus on the listener. That way readers will register the text, but will focus on the reaction of the listener!

Second; You can put more or less focus on the background. If you want to make your subject stand out of the background (or if you’d like to make an ugly background more or less disappear), use a large aperture-size. If you want to make your subject go up in the background, or put more focus on the connection between your subject and the background, use small aperture-sizes.

Setting Your Aperture

If you want to select your aperture manually for a photo there are two modes you can use: aperture priority mode (A or Av) and manual mode (M). In aperture-priority mode, you select the aperture, and the camera automatically selects your shutter speed. In manual mode, you select both the aperture and shutter speed manually.

Conclusion

Aperture is arguably the single most important setting of all camera settings simply because it has so many effects on your photo. In this post I only discussed a few of all effects aperture has on your photo. Some effects that were not discussed are ability to focus in low light, possible focus shift on some lenses, sharpness due to diffraction, sharpness due to lens quality and the visibility of camera-sensor dust specks . It is good to know these effects exist and that aperture is involved.

Lastly, as you know; practice makes perfect. So go of and start making experimenting! I’m looking forward to seeing the results.

Coming up…

An extensive beginners guide on shutter-speed.


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