DSLR vs P&S a replay of Film vs Digital?

Peter Irwin wrote:
In rec.photo.equipment.35mm Wilba wrote:
So you're saying that the entire site should not be taken seriously? Their
dictionary definition of "Prime lens" is "A lens with a fixed focal length"
(http://photonotes.org/cgi-bin/entry.pl?id=Primelens).

What's the right definition?

Some pedants insist that "prime lens" is best left as the
term for the main lens when using a supplementary lens.
They may have a point, but it is a widely used piece of slang
and rarely causes confusion.

But their definition of "zoom lens" is just wrong.
There are many lenses of adjustable focal length
which are not zoom lenses. For instance, a front cell
focussing lens is focussed by changing the focal length,
and would not be called a zoom lens by anyone.

A zoom lens is one which allows the focal length to
be changed and remains in focus when the focal length is
adjusted.
similarly, the term "telephoto" frequently gets used to
describe anything that has a longer focal length than a
standard lens, but the term really applies to any lens which
is physically shorter than it's focal length.

Peter.

On Sun, 18 Nov 2007 01:42:40 +0000 (UTC), Peter Irwin wrote:

In rec.photo.equipment.35mm Wilba wrote:

So you're saying that the entire site should not be taken seriously? Their
dictionary definition of "Prime lens" is "A lens with a fixed focal length"
(http://photonotes.org/cgi-bin/entry.pl?id=Primelens).

What's the right definition?

Some pedants insist that "prime lens" is best left as the
term for the main lens when using a supplementary lens.
They may have a point, but it is a widely used piece of slang
and rarely causes confusion.

But their definition of "zoom lens" is just wrong.
There are many lenses of adjustable focal length
which are not zoom lenses. For instance, a front cell
focussing lens is focussed by changing the focal length,
and would not be called a zoom lens by anyone.

A zoom lens is one which allows the focal length to
be changed and remains in focus when the focal length is
adjusted.

Peter.

That's a parfocal zoom-lens. A zoom-lens need not be parfocal to be called a
zoom-lens. There are many telescope and microscope zoom-lens oculars that are
anything but parfocal. Though called parfocal zoom-lenses none are truly
parfocal. This is why they have to depend on auto-focusing mechanisms after each
new zoom setting and always allow for some "slop" at the infinity stop. It's
easier to correct for minor difference in focusing than it is to compensate in
glass configurations and the more complex internal lens shifting methods that
would be required.

"Wilba" wrote in message
...
Neil Harrington wrote:
John Navas wrote:

Moreover tests of these lenses confirm that they do measure up to
Leica standards; e.g., "everything you'd expect from Leica glass"
http://www.popphoto.com/cameralenses/4597/lens-test-panasonic-leica-d-summilux-25mm-f14-af.html

That's "everything you'd expect from Leica glass" by Julia Silber, who in
the first paragraph uses "prime" when she means fixed focal length. I
think she's the only columnist in Pop Photo who does employ that popular
but ignorant misusage. (Herbert Keppler certainly never does.) Someone
that careless with language is not to be taken very seriously.

So you're saying that the entire site should not be taken seriously? Their
dictionary definition of "Prime lens" is "A lens with a fixed focal
length" (http://photonotes.org/cgi-bin/entry.pl?id=Primelens).

That isn't "their dictionary definitiuon." AFAIK, Photonotes.org has nothing
to do with Pop Photo.


What's the right definition?

"Prime lens" means the camera lens as opposed to some other lens or optical
device used with it, such as a close-up lens, tele converter, etc. When used
with such a device, the camera lens itself is the prime lens -- whether it's
fixed focal length or zoom makes no difference.

There are variable focal length prime lenses made by Schneider, Zeiss and
others which are catalogued just that way: "variable primes."
http://schneiderkreuznach.com/pdf/ki...le_prime_e.pdf
http://www.cinequip.com/Category_det...ategory=Lenses
http://rentacam.ru/eng/index.php?area=article&id_art=58
http://www.oscars.org/scitech/1998/winners.html (scroll down)

Nikon, for example, has NEVER used "prime" to mean fixed focal length in any
of its lens literature. Neither have most other camera and lens
manufacturers.

Neil

SMS just provided something very useful to all of us. Anyone that doesn't want
SMS poking his ignorant nose into threads and hijacking them for attention for
himself with his usual trolling tactics, just use one of these email addresses
in your post. This is his block list.

How convenient of him to help all of us this way.



On Sat, 17 Nov 2007 00:21:27 -0800, SMS ???• ?
wrote:

Neil Harrington wrote:
"GeraldG." wrote in message
...
On Fri, 16 Nov 2007 09:43:11 -0500, "Neil Harrington"

wrote:

"Helmsman3" wrote in message
...

BTW, how many different names are you posting under?

Haven't hit on one you really like yet?

LOL, at least he keeps making everyone's kill-files longer and longer.
Hasn't been this much crap since "George Preddy" was around.

Here's my most current list:

"Peter Irwin" wrote in message
...
In rec.photo.equipment.35mm Wilba wrote:

So you're saying that the entire site should not be taken seriously?
Their
dictionary definition of "Prime lens" is "A lens with a fixed focal
length"
(http://photonotes.org/cgi-bin/entry.pl?id=Primelens).

What's the right definition?

Some pedants insist that "prime lens" is best left as the
term for the main lens when using a supplementary lens.

Yes. When in doubt, go with the pedants, I always say.


They may have a point, but it is a widely used piece of slang
and rarely causes confusion.

"Rarely" perhaps, but it does cause confusion when the term is used properly
but is misunderstood by those who think it means "fixed focal length." And
that does happen. It's almost certainly how the misusage got started in the
first place.


But their definition of "zoom lens" is just wrong.

Who's the "they" that your "their" refers to? No one in this thread has
defined "zoom lens" at all, have they?


There are many lenses of adjustable focal length
which are not zoom lenses. For instance, a front cell
focussing lens is focussed by changing the focal length,
and would not be called a zoom lens by anyone.

A zoom lens is one which allows the focal length to
be changed and remains in focus when the focal length is
adjusted.

Yes, true zoom lenses are supposed to be parfocal. Whether they are
*precisely* so is often doubtful. Many so-called zooms are more properly
called varifocal lenses, especially those built into compact cameras, though
some SLR "zooms" are really varifocals also.

The difference is in the degree of misusage. Many manufacturers use the term
"zoom" to mean certain kinds of lenses (esp. projection lenses) and other
lenticular devices (binoculars, telescopes, etc.) that are not really
parfocal or even approximately so. Nikon, for example, has "zoom" binoculars
which I suppose are probably not true zooms in that sense.

But Nikon NEVER uses "prime" to mean fixed focal length. Neither did
Minolta, when Minolta was still in that business. I think to some extent we
should accept the manufacturers' usage as acceptable -- as opposed to a
misusage which only started because someone misunderstood the term "prime
lens" and that misusage spread via the Usenet.

A "zoom" lens may really be a varifocal instead, but it does essentially
what a zoom lens does and what people expect a zoom lens to do. The
difference as a practical matter is trifling.

To take "prime" as meaning fixed focal length when the term never actually
meant anything remotely like that is entirely different, and far less
acceptable.

Neil

Neil Harrington wrote:
Wilba wrote:
Neil Harrington wrote:
John Navas wrote:

Moreover tests of these lenses confirm that they do measure up to
Leica standards; e.g., "everything you'd expect from Leica glass"
http://www.popphoto.com/cameralenses/4597/lens-test-panasonic-leica-d-summilux-25mm-f14-af.html

That's "everything you'd expect from Leica glass" by Julia Silber, who
in the first paragraph uses "prime" when she means fixed focal length. I
think she's the only columnist in Pop Photo who does employ that popular
but ignorant misusage. (Herbert Keppler certainly never does.) Someone
that careless with language is not to be taken very seriously.

So you're saying that the entire site should not be taken seriously?
Their dictionary definition of "Prime lens" is "A lens with a fixed focal
length" (http://photonotes.org/cgi-bin/entry.pl?id=Primelens).

That isn't "their dictionary definitiuon." AFAIK, Photonotes.org has
nothing to do with Pop Photo.

Yeah, sorry. I went looking, got distracted, and thought I got there from a
link on popphoto.

What's the right definition?

"Prime lens" means the camera lens as opposed to some other lens or
optical device used with it, such as a close-up lens, tele converter, etc.
When used with such a device, the camera lens itself is the prime lens --
whether it's fixed focal length or zoom makes no difference.

There are variable focal length prime lenses made by Schneider, Zeiss and
others which are catalogued just that way: "variable primes."
http://schneiderkreuznach.com/pdf/ki...le_prime_e.pdf
http://www.cinequip.com/Category_det...ategory=Lenses
http://rentacam.ru/eng/index.php?area=article&id_art=58
http://www.oscars.org/scitech/1998/winners.html (scroll down)

Nikon, for example, has NEVER used "prime" to mean fixed focal length
in any of its lens literature. Neither have most other camera and lens
manufacturers.

OK, so it's one of those terms that is irredeemably contaminated, like the
way people say laptop when they mean notebook, or massive when they mean
large. When I searched for "prime lens", none of the first three or four
definitions I found mentioned the definition you use, they all referred
first to fixed focal length.

"SMS ???. ?" wrote in message
...
grant_jiles wrote:

About as pathetic as a person with that much time on their hands to
compile a
list like that.

No compiling at all. Just dumping the contents of my Thunderbird filter
list for rec.photo.digital. It may help others in setting up their kill
files without having to add the e-mail addresses individually.

With a good filter list, newsgroups becomes much more readable and more
useful. It actually saves time by not having to wade through hundreds of
posts by know-it-alls that know nothing.

Add one more of course, ".

Easier than entering all that stuff into a killfile, which obviously will
only grow and grow (and I assume he never bothers re-using his old ones
anyway), henceforth I'll just assume any unknown poster supporting that jerk
is the jerk himself, and ignore it. Likewise I'll just assume any other
idiotic post is from the same jerk, regardless of the subject or name used.
It's easy enough to pick him out from his headers, but why waste the time.

Neil

In rec.photo.equipment.35mm arnold ziffendorfer wrote:
On Sun, 18 Nov 2007 01:42:40 +0000 (UTC), Peter Irwin wrote:

But their definition of "zoom lens" is just wrong.
There are many lenses of adjustable focal length
which are not zoom lenses. For instance, a front cell
focussing lens is focussed by changing the focal length,
and would not be called a zoom lens by anyone.

A zoom lens is one which allows the focal length to
be changed and remains in focus when the focal length is
adjusted.

Peter.

That's a parfocal zoom-lens. A zoom-lens need not be parfocal to be called a
zoom-lens.

OK. How would you class a front cell focussing triplet?
It is designed to be variable in focal length in order
to focus. I sure wouldn't call it a zoom.

How would you class a variable focal length Dallmeyer Adon?
It can adjust to a pretty huge range of focal lengths
for different magnifications, but not only do you have to
refocus it, you have to calculate the aperture each time
you change it. I would hardly call it a "zoom"; it is a fairly
difficult lens to use.

Though called parfocal zoom-lenses none are truly
parfocal.

Any zoom lens worthy of the name should be close enough
that you can get away without refocussing.

Peter.
--

arnold ziffendorfer wrote:

On Sun, 18 Nov 2007 01:42:40 +0000 (UTC), Peter Irwin wrote:


In rec.photo.equipment.35mm Wilba wrote:

So you're saying that the entire site should not be taken seriously? Their
dictionary definition of "Prime lens" is "A lens with a fixed focal length"
(http://photonotes.org/cgi-bin/entry.pl?id=Primelens).

What's the right definition?


Some pedants insist that "prime lens" is best left as the
term for the main lens when using a supplementary lens.
They may have a point, but it is a widely used piece of slang
and rarely causes confusion.

But their definition of "zoom lens" is just wrong.
There are many lenses of adjustable focal length
which are not zoom lenses. For instance, a front cell
focussing lens is focussed by changing the focal length,
and would not be called a zoom lens by anyone.

A zoom lens is one which allows the focal length to
be changed and remains in focus when the focal length is
adjusted.

Peter.


That's a parfocal zoom-lens. A zoom-lens need not be parfocal to be called a
zoom-lens. There are many telescope and microscope zoom-lens oculars that are
anything but parfocal. Though called parfocal zoom-lenses none are truly
parfocal. This is why they have to depend on auto-focusing mechanisms after each
new zoom setting and always allow for some "slop" at the infinity stop. It's
easier to correct for minor difference in focusing than it is to compensate in
glass configurations and the more complex internal lens shifting methods that
would be required.



This is an important consideration with moving media.

A cinematographer should plan his shot by focusing on the longest focal
length to be used and take advantage of the larger depth of field to
compensate for any error when going, (or leaving), a wide shot.

One of the oldest tricks in the book...

JT

On Sun, 18 Nov 2007 04:59:25 GMT, Grumpy AuContraire
wrote:



arnold ziffendorfer wrote:

On Sun, 18 Nov 2007 01:42:40 +0000 (UTC), Peter Irwin wrote:


In rec.photo.equipment.35mm Wilba wrote:

So you're saying that the entire site should not be taken seriously? Their
dictionary definition of "Prime lens" is "A lens with a fixed focal length"
(http://photonotes.org/cgi-bin/entry.pl?id=Primelens).

What's the right definition?


Some pedants insist that "prime lens" is best left as the
term for the main lens when using a supplementary lens.
They may have a point, but it is a widely used piece of slang
and rarely causes confusion.

But their definition of "zoom lens" is just wrong.
There are many lenses of adjustable focal length
which are not zoom lenses. For instance, a front cell
focussing lens is focussed by changing the focal length,
and would not be called a zoom lens by anyone.

A zoom lens is one which allows the focal length to
be changed and remains in focus when the focal length is
adjusted.

Peter.


That's a parfocal zoom-lens. A zoom-lens need not be parfocal to be called a
zoom-lens. There are many telescope and microscope zoom-lens oculars that are
anything but parfocal. Though called parfocal zoom-lenses none are truly
parfocal. This is why they have to depend on auto-focusing mechanisms after each
new zoom setting and always allow for some "slop" at the infinity stop. It's
easier to correct for minor difference in focusing than it is to compensate in
glass configurations and the more complex internal lens shifting methods that
would be required.



This is an important consideration with moving media.

A cinematographer should plan his shot by focusing on the longest focal
length to be used and take advantage of the larger depth of field to
compensate for any error when going, (or leaving), a wide shot.

One of the oldest tricks in the book...

JT

Exactly. This is why I see no huge compelling argument to the "my camera focuses
faster than your camera" childishness. I only use the auto-focus on my camera to
quickly find either a nice average to put the subject(s) within the DOF needed
or when I use a hyperfocal setting so nothing is missed. The same as I've done
for the last 40 years in all my cameras, manual or otherwise. Once that is done
I lock it into manual focus so it stays there. Occasionally using the manual
adjustment to touch up on what the camera ADVISED for a starting point. No
different than the advice you get from the exposure readings. How often that is
wrong too. Auto-focus may get me there quicker in most situations but is by no
means the answer to worthwhile photography. I do just as well without it if I
need to. I'll turn it off completely depending on the shooting scenario.
Particularly with macro-photography where it is more of a huge hindrance than
any kind of a help.

If the "fast auto-focus" admirers only realized how often they reveal their own
lack of talent and skills at photography. Snap-shooters that have been
brainwashed into thinking that they can buy a camera that will magically bestow
them with talent. They need to read Jack & the Beanstalk for hints on how to
find some magic beans while they're at it.