Originally posted by marcusBMG However the aperture doesn't change - it is a fixed property of the lens.
But focal length is also a fixed property of a lens, yet to provide more 'useful' information for an enthusiast the norm is to state 'equivalent focal length'.
If I have a FF with a 50mm/F2 lens I have an idea what I will be able to achieve with regards to focal depth, light sensitivity and width of view.
Back in the day of film there really was only one film size for the majority - 35mm. Problem now is that there are 4 competing sensor sizes for the masses - 1", 4/3, APS-C and 35mm.
Now instead of being able to judge the 'performance' of a camera simply by looking at the focal length and max aperture, one has to consider two additional numbers (sensor size and max usable ISO).
An adjusted aperature simply makes it easier (like adjusted focal length) to compare apples to oranges.
---------- Post added 10-29-17 at 07:23 AM ----------
Originally posted by BrianR ... it is less impressive from a marketing standpoint...
That sums it up nicely... it has everything to do with marketing, and very little to do with providing useful information so the average joe can make an informed decision.
---------- Post added 10-29-17 at 07:23 AM ----------
Originally posted by BrianR ... it is less impressive from a marketing standpoint...
That sums it up nicely... it has everything to do with marketing, and very little to do with providing useful information so the average joe can make an informed decision.