I made a reference in a group of someone not ever having to know the difference between f-stop & aperture and someone else called me out on the difference. Where most people think they are the same, I posted this as an example to the difference.
The f-stop is responsible for DOF (Depth of Field). The lower the f-stop, the lower the number of items that are in focus relative to subject. The higher the f-stop, the higher number of things that are in focus relative to subject. Aperture is the opening that adjusts to the f-stop value. High f-stop, low aperture opening and vice-versa.
For example, on a bright, sunny day with some daisies:
f/32 – narrow aperture and slow shutter speed – a lot of the picture is in focus relative to subject
f/5.6 – wide aperture and fast shutter speed – very little (if any) of the picture is in focus relative to subject
I know it really does seem like semantics, but I believe the difference does work hand in hand with each other in the grand scheme.
Garth Smith
Its semantics, splitting very fine hairs indeed and some places in your post the alternative word can be used.
eg
The f-stop is responsible for DOF (Depth of Field). I actually think this is wrong.
The aperture is responsible for DOF (Depth of Field).
The f-stop is the measure of that aperture. It is the number that describes how far open the lens aperture was.
Now I am splitting hairs too.
Its a bit like distance and kilometres. Kilometres is a measure of distance,
F/stop is a measure of aperture.
Diado
It’s also worth pointing out that you won’t necessarily get more in focus with a higher f-stop (narrower aperture) – Once you get past F/16ish you start losing detail due to diffraction on most lenses. Apparently the “sweet spot” for most lenses is around F/8, although I’ve found on my two lenses that it’s closer to F/11.
William Sanford:
I have a picture here with the following details:
Nikon D200
AF-S Nikkor 55-200mm ED VR
f/22
exp. time 1/8000 sec.
ISO 1600
William Sanford
First, the linear aperture is the diameter of the opening and the relative aperture (F/stop) focal length divided by linear aperture.
The reason I explained it like I did, it seems easy to remember the higher the f-stop; the more that will be in the shot (DoF).
Diado
Although it’s a little hard to tell due to the size, it would appear that the shot you showed is at F/22 is losing detail around the edges of the trees.
Just out of interest, if you were shooting directly into the sun, why did you use such a high ISO?
William Sanford:
It is the size. The original shows a little graininess because the ISO is at 1600, but the detail is there. I was trying the shot at 1/8000th of a second and left the ISO on auto.
Garth Smith
from wikipedia (not that wikipedia is the last word on any subject)
Aperture
Adjustment of the lens opening, measured as f-number, which controls the amount of light passing through the lens. Aperture also has an effect on depth of field and diffraction – the higher the f-number, the smaller the opening, the less light, the greater the depth of field, and the more the diffraction blur. The focal length divided by the f-number gives the effective aperture diameter.
William Sanford
The subtle difference with Aperture and F-stop is Aperture is the actual opening and F-stop is a measurement.
Linear aperture is the size of the opeinging that the light passes through.
Relative aperture is F/stop which is focal length divided by linear aperture.
L.D. Bonner
I think a visual would be appropriate , but im an absolute newbie, so everything makes more sense visually. continue.. good discussion.