We`ve already looked at the role played by pixel size and the benefits of a larger sensor. But, before you rush out to buy the camera with the biggest sensor you can, it`s worth bearing in mind that you won`t always see its full advantage.
Key takeaways:
For the same field-of-view, a larger format will have shallower depth-of-field at the same F-number.
Shallow depth-of-field can be a creative benefit, up to a point, but you sometimes need a certain depth-of-field.
You can stop down a large sensor camera to match the depth-of-field of a smaller one, but you end up with comparable image quality if you do.
All formats are a series of compromises and there is no correct balance to strike.
The depth-of-field trade-off
As we`ve seen, if you can achieve the same exposure settings, a larger sensor will have a chance to absorb more light and hence give better image quality. But achieving the same exposure value usually requires you to use the same f-number.
With the same f-number, a larger format will also have shallower depth-of-field, which will sometimes be desirable but other times not. Depending on your tastes and shooting style, shallow depth-of-field (and the additional light that usually comes with it) can be a valuable creative tool. But only up to a point, and not in all circumstances.
A `full-frame` sensor tends to require large lenses but can capture lots of light. This extra light capture comes with shallow depth-of-field (for better or worse).
In situations where you need more depth-of-field it`s possible to stop down the lens on a large sensor camera, but doing so will reduce the amount of light available to your camera: at which point you`ll see the advantage over a smaller-sensor system begin to diminish (while still having to deal with the larger format`s size, weight and cost).
Bigger is usually better, but how much better do you need?
Also, the examples we`ve used were shot in relatively low light. In ...
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