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Old March 6th 20, 06:25 PM posted to rec.photo.digital.slr-systems
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Default Are primes brighter and sharper than wide open zooms

PRIME:

Correct, the meaning of the word "prime" is equivalent to "primary",

.... meaning the primary image forming lens in a photographic imaging system,

.... and can be any type of lens, including a zoom lens,

.... where a secondary or auxiliary lens is a non-image forming lens in the photographic imaging system.

It's all math and science.

Think of the mathematical scientific marker ( ' ) meaning "prime",

.... where if we were to draw out a schematic of our photographic imaging system,

.... the primary image forming lens would be marked with a ( ' ) prime indicator,

.... and supplemental or auxiliary lenses would be marked as such, as non-prime,

.... regardless of any of the lenses or lens assemblies having focal lengths that are fixed or single or multiple or variable or zoom.

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FFL:

Fixed Focal Length lens wise, almost no one has ever seen one ( a diopter, perhaps ... but not what we are talking about )?

"fixed focal length" lens assemblies have no focusing mechanism of their own, and depend on camera movement, or attachment to an adjustable bellows between the lens and the camera, in order to focus.

People are thinking of single focal length lenses, which do have internal focusing mechanisms, and can focus from infinity-ish to closer-ish.

So, no, even FFL is an inappropriate reference considering what people are really referring to - their 50mm f/1.4 camera-maker-branded lens assembly or something like that, which they would consider broken if it's focusing mechanism failed and left the lens assembly at any fixed focal length.

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JARGON:

I congratulate you on recoiling against alienating inaccurate and inappropriate jargon which confuses oldies and newbies alike.

And I join you in trying to get us all to stop using berserker jargon.

If we're going to invent meaningless jargon, just call things "thingamabob" and "whatsit".

Thanks for exploring this.

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On Wednesday, September 28, 2005
at 11:57:22 AM UTC-4, Nostrobino wrote:
Zoom lenses ARE prime lenses,
notwithstanding the now-popular
misusage of "prime."

A prime lens is the camera lens as
distinct from some other lens or
lenticular device (close-up lens,
tele converter, etc.) used with it.
It has meant that since long before
zoom lenses became commonplace, and
therefore no need to use another
term to mean "non-zoom."

"Prime" is properly used in the
sense of primary, main, chief or
original--all dictionary definitions
for "prime."

There is NO dictionary definition
for "prime" which means fixed focal
length or single focal length, or
fixed or single anything else.

It would be nice if this nonsensical
misusage, which obviously is based on
someone's misunderstanding of the
term some years ago (and then spread
like cancer through the power of the
Internet) could be stamped out.
Surely "FFL" is at least as easy to
type as "prime" anyway, and there
never was any reason other than
shortness to replace "fixed focal
length" with the incorrect term.

N.


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