- Am I right to find that the lenses do not have a name, or should I see the description given to the manufacturer as the only correct name, and is there a variation on this a fault of # 39; spelling?
A lens is a tool, part of the camera system. If I ask you to grab me a socket wrench, I have given you an unnecessary description of the tool I need. If one asks you to grab me a 3/8 "socket wrench, a 12" extension and a 1/2 "socket, then you now know what to grab for me.
Ditto with a goal. If I say catch me at a wide angle, you guess. If I say I want a 16-35mm f / 2.8, you now know what I need.
These things don't need names because they have one: the goal. As with all tools, we select and communicate about them by their function.
- How are lenses and cameras different? Why does one have a clear unique name and the other does not? My working hypothesis is that one is likely to have several lenses and that one wishes to differentiate them by their unique characteristics, but in practice, I designate them with their reason / reason for which I have them purchased.
See the tool point above. You will buy a drill press with a marketable name, but each piece you buy will bear the name of its function.
Have you seen the spec sheet for a camera? There are many, many features – an all-encompassing name would be ridiculous. So they get model names to market and compare.
A lens has two essential pieces of information: focal length and maximum aperture – that’s it.
Manufacturers are asking for extra money for a quieter / more precise focus motor, ED glass, stabilization, etc.
I have never made such a claim. I have said that focal length and aperture are essential for shooting, while the others are "nice to have" in the vast majority of cases.
If I go to a football game during the day, then I will tell you that I want to have a 70-200 f / 4 and a 400 f / 5.6 with me. If you offered me a 70-200 f / 2.8 or a 400 f / 4, I wouldn't say no, of course, but I could work with less.
The fact that these lenses have USM technology or a great lens is great, but not as critical to my decision making process as focal length and aperture. For example, I would take a manual focus lens with the right focal length and the right aperture for my needs compared to a super new and super cool autofocus lens in the wrong focal range.
So yes, there are other features of a lens – but the focal length and the aperture range govern most of whether or not you get the photo you want.