When you say you have a "Prime" lens...

[LowSpark420]

Is a "prime" lens to mean it only has one focal length?

[LowSpark420]

Nevermind, wikipedia answered that for me. :)

[KCMO Al]

Yes, the same Wikipedia that proclaimed the U.S. was celebrating "700 years of independence."
"Prime" is a term coined to describe a lens with one focal length. Many user would say "Choice" lenses are those that have more than one...a "Zoom" lens, for example.

[Persephone]

Yes, the same Wikipedia that proclaimed the U.S. was celebrating "700 years of independence."

Though I do agree that Wikipedia's accuracy is sometimes suspect, a better line of argument for debunking Wikipedia is to see how long factual problems or inaccuracies last. Sometimes it's fairly bad, but most of the time, it's relatively pretty good, plus for more things you can check the source, which is usually online.

[JeffreyG]

When wiki was first getting started, it was fun to point out that the accuracy of something that can be written and edited by anyone must be suspect. But as time has passed, the opposite has proven to be true. For the vast majority of topics (especially those that are not controversial or quickly evolving) Wikipedia has proven to be very accurate indeed.

It's not going to go down in history as a totally revolutionary technology (like smart search engines will), but it will be recognized long term as a key technology of our era.

[Kolor-Pikker]

The term "prime" probably relates to prime numbers, which can only be divided by 1 or themselfs.
Since a lens's zoom range is gotten by dividing the long end of the focal length by the short end, the term prime makes sense, since there is no other number to divide by.

[number six]

The term "prime" probably relates to prime numbers, which can only be divided by 1 or themselfs.
Since a lens's zoom range is gotten by dividing the long end of the focal length by the short end, the term prime makes sense, since there is no other number to divide by.

:p

Interesting theory, never thought of that. But a non-zoom lens would always have a zoom ratio of 1:1, right?

However, 1 is not a prime. A prime is a natural number that has exactly two distinct divisors, 1 and itself. Hence the smallest prime is 2.

-js

[Kolor-Pikker]

But a non-zoom lens would always have a zoom ratio of 1:1, right?
It probably wouldn't have any zoom ratio, since it would be pointless to even mention it.
In any case, wiki isn't too clear on it, I wonder if anyone actually knows why exactly the word "prime" is used and if it really does mean "primary"?

[20droger]

In the really olden days, there were just camera lenses.

Then someone invented adjustable lenses, lenses that could change focal lengths. The earliest versions of these lenses changed focal length by moving elements in and out with a linear or push-pull motion. This motion was called zooming, and the lenses were called zoom lenses. Because of the design of these early lenses, one zoomed out (away from the camera) to increased the focal length, and zoomed in (towards the camera) to decrease focal length. These terms hold today, regardless of the motion required to increase or decrease focal length.

Lenses with only one focal length were considered basic lenses. But the term "basic" was so blasé, and seemed to imply lower quality. The powers that be in the industry (the lens manufacturers) looked for a synonym for "basic" and came up with "prime." Thus, the prime lens was born. (It didn't hurt that "prime," while meaning "basic" in this case, had suggestions of quality and importance to it.

All single focal length lenses are prime lenses, regardless of quality or other features.

[number six]

Yeah, in my film days I never heard of a prime lens. First time I heard the term was when I was looking to buy a 300D.

-js

[Jeff]

Wow, I thought there would only be one response to this....yes. Now we're getting into theory, etc. Fun.