The diaphragm consists of fragile blades superimposed inside an objective, and its function is to let more or less light through. That’s why this article was born, and we want to explore all the details about it.
The representation of the diaphragm in your lens and Photography
The nomenclature ƒ represents the lens diaphragm. Every time you look at something like ƒ/3.5, ƒ/1.4, or ƒ/value, you know they are values referring to the aperture of the diaphragm.
The Diaphragm In The Aperture Photography
Please write it down: The smaller the number, the larger the aperture, and lighter pass through the lens; therefore, the larger the number, the smaller the aperture and less light reaching the camera’s sensor.
In the previous image, we show between ƒ/2.8 and ƒ/16, but there are Nikon lenses with apertures up to ƒ/1.4 and Canon with ƒ/1.2 apertures, both of excellent quality, but which requires a high investment. Maybe not interesting for those who have Photography as a hobby.
The Diagram And The Results
We already know that it is responsible for the amount of light that passes through the objective, but we also want to bring up some crucial points besides the light, which result from the different values of the aperture.
Field Depth
One of the main factors that photographers consider when acquiring a more transparent lens, such as a ƒ/1.4, is the possibility of having a shallow depth of field, i.e., working with very out-of-focus backgrounds. Depth of field is the amount of blur of the out-of-focus area in a photograph.
The Diaphragm And The Sharpness
This factor many people who are already photographers do not know either. In light of the depth of field and working with different openings, a diaphragm can provide you with a picture that is more or less sharp, focused in the same area.
100% of the time, even on top lenses like a Nikon 35mm ƒ/1.4 or a Canon 85mm ƒ/1.2, when using the maximum aperture, you don’t get the best result in sharpness. Of course, some photographers don’t care about this detail, and https://skylum.com/blog/raw-photo-editing-made-easy already pretty picky about sharpness.
Best lens sharpness results are around two ƒ/stop upwards.
In practice: For a lens with a maximum aperture of ƒ/2.8, the best sharpness results will be around ƒ/5.6. For kit lenses (18-55, for example) with a maximum aperture of ƒ/3.5, the best results will be on pictures with ƒ/8.