I started the exciting journey of digital photography with 18-55 mm kit lens as my first glass. Being a variable aperture lens, it has a minimum aperture of F3.5 at 18 mm. The lens saw its fair share of adventures and ultimately was replaced with a fixed aperture lens.
Value of aperture is a part of the exposure triangle, which means it affects the amount of light hitting DSLR camera sensor. In addition to light, it also affects the amount of area in focus which is often referred to as Depth of Field. An image taken at F8 will have almost everything in focus when compared to an image taken at F2.8. Before someone jumps on me with their DOF vocabulary, this post is not about depth of field (DOF) in detail discussion. It is a simple comparison post for beginners to understand how lens aperture impacts background blur and low light performance.
DSLR used: Canon 6D
Lens used: Tamron 24-70 mm F2.8 DI VC USD
Bokeh (background blur) comparison:
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| F2.8 vs F3.5 vs F4 |
Comparison animation in the above photo shows how the background behind subject changes with variation in the aperture. At a value of F2.8, it looks very smooth and silky. With an increase in aperture value, the background prominence starts to increase. Let's see how much more light do we get when taking an indoor shot with wide open F2.8 aperture.
Low light comparison:
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| F2.8 vs F3.5 vs F4 |
Above animation clearly explains the importance of using a wider aperture lens in low light conditions. The amount of difference observed between an F4 aperture lens and an F2.8 lens is quite a lot. In case the object is moving in low light conditions, having a decent shutter speed is always beneficial to get the shot. This is why wide aperture lenses are sometimes also called as fast lenses as they allow you to shoot at higher shutter speed when wide open.
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This is on my list of things that I would like to buy when I finally get everything needed for the house and my son's school. It's going to be a big reward for myself.
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