aperture Flashcards
What is aperture and what can it do?
opening in a lens through which light passes to enter the camera.
Its like a pupil. The larger the opening the more the light passes through, the smaller the opening the lesser the light passes through.
It can control brightness and control the depth of field.
i) Brightness = the bigger the aperture, the more the brightness of our image.
ii) Depth of field = the bigger the aperture, the lower the depth of our image.
Explain how aperture affects brightness.
If the aperture is large, then more light can pass though the lens, this means more light is being gathered hence our image will be brighter. If the aperture is narrower, then less light passes through the lens hence less light is gathered so, our image will be darker.
Explain how aperture affects depth of field.
Think of aperture as our eye lids. As we open our eyes wide , we can see the targets near us clearly but those who are far away are blurred. In order to look at the far away objects more clearly what we will do? we will squint our eyes, this will allows us to focus on far away targets. This squinting is equivalent to narrower aperture.
So, the bigger the aperture, the more the background blur and foreground blur. The narrower the aperture, the sharper the background and foregrounds of a target.
What should we be aware of when using narrower aperture?
I)Narrower aperture will make even the dust on lens be very sharp. (Since dust on lens is considered as foreground materials) . So make sure to clean the lens beforehand.
II) Too narrow aperture can also create diffraction of light, which will cause the sharpness to decrease. This doesn’t mean you should not use extremely narrow aperture, it just means that you can take images, just know that you will have to sacrifice some sharpness.
What should we be aware of when using wider aperture?
I) Wider aperture images are tend to be not as sharp as narrow aperture images. Especially at the corners of the image.
II) wider aperture can cause lens aberration. There are many times of aberration. Ex dark corners in an image, images of stars might look like streaks if they are in the corner of the image.
Lens aberration are not ideal but they definitely would not ruin your photo so use wide aperture if necessary.
What is a starburst effect?
In narrower apertures, bright source of light (Ex sun, street lights) will be seen to be equipped with long rays. You can see this if you look at street light with your eyes squinting.
Which is more important to look in a camera, maximum aperture or minimum aperture?
Most modern cameras have the same minimum aperture. Mostly people look for the maximum aperture. It allows you to take photographs at darker environment. If a camera has a low aperture, the image is going to be dark and we will find it hard to focus on our targets.
How to read aperture?
aperture is a fraction. So in descending order:
f/1.4 > f/2.0 > f/2.8 > … > f/16.0 > f/22.0
here f/1.4 is large aperture and f/22.0 is narrow aperture.
In camera is sometimes shown as simply f1.4 , f2.0 and etc. (omitting the slash sign)
When to use which aperture?
f/0.95 – f/1.4 – Such “fast” maximum apertures are only available on premium prime lenses, allowing them to gather as much light as possible. This makes them ideal for any kind of low-light photography (such as photographing the night sky, wedding receptions, portraits in dimly-lit rooms, corporate events, etc). With such wide f-stops, you will get very shallow depth of field at close distances, where the subject will appear separated from the background.
**f/1.8 – f/2.0 **– Some enthusiast-grade prime lenses are limited to f/1.8, which still has very good low-light capabilities. Also, if your purpose is to yield aesthetically-pleasing images with shallow focus, these lenses be of tremendous value. Shooting between f/1.8 and f/2 typically turns your backgrounds nice and creamy for portraiture and other similar types of photography.
f/2.8 – f/4 – Most zoom lenses are limited to a maximum aperture of f/2.8 to f/4 at best. While they are not as capable as f/1.4 lenses in terms of light-gathering capabilities, they are still enough to shoot in reasonably low light conditions, especially if the lens or camera has image stabilization. You’ll get some subject separation at these apertures, but usually not enough to make the background completely fuzzy. Such apertures are great for travel, sports, and wildlife photography.
f/5.6 – f/8 – This is the right starting point for most landscape and architectural photography. It’s also ideal for documentary and portrait photography where you don’t want a blurry background. Also, most lenses are sharpest around f/5.6, which doesn’t matter as much as getting the right depth of field, but is still nice.
f/11 – f/16 – Typically used for photographing scenes where as much depth of field as possible is needed, like macro photography or landscape photography with a nearby foreground. Even though these apertures offer more depth of field, they do lose some low-level sharpness due to the effect of lens diffraction.
f/22 and smaller – Only shoot at such small apertures if you know what you are doing. Sharpness suffers greatly at f/22 and smaller apertures because of diffraction, so you should avoid using them when possible. If you need to get more depth of field, it is usually best to move away from your subject or use a focus stacking technique instead.
