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What is 1:1 magnification on a Macro lens?

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Anonymous
January 13, 2005 11:14:30 PM

Archived from groups: rec.photo.digital (More info?)

What do they mean when they refer to 1:1 magnification on a Canon 100mm
macro f2.8?

It seems like a 1:1 ration wouldn't give any magnification so what's the
deal?

Jimmy
Anonymous
January 13, 2005 11:14:31 PM

Archived from groups: rec.photo.digital (More info?)

"Jimmy Smith" <nospam@pleaseno.more> wrote in message
news:E%EFd.25147$vM4.23243@bignews3.bellsouth.net...
> What do they mean when they refer to 1:1 magnification on a Canon 100mm
> macro f2.8?
>
> It seems like a 1:1 ration wouldn't give any magnification so what's the
> deal?
>
> Jimmy

The ratio of 1:1 is the comparison of how big the subject you're shooting
will be compared with it's actual size on the negative (or sensor).

In other words... A lens that is mounted on a film camera, shooting at a
range giving 1:1 macro enlargement...that takes a close-up of a grape that
is one centimeter accross...will produce an image of that grape that takes
up one centimeter of the actual film's surface.

How this translates to tiny sensors in little digicams, or to larger sensors
with DSLRs is a bit more confusing, but the idea is similar. It's not about
magnification via the optics, so much as it is the len's ability to focus
CLOSE enough to the subject to produce this ratio.

If you have a 50mm lens (assuming a 35mm system) that does 1:1, you can be
sure that to acheive this, you must be only a few **inches** away from your
subject. With a 180mm 1:1 macro lens, you'll have the luxery of nearly
quadrupling the distance from your subject, while still acheiving 1:1 images
on the film/sensor plane.
-Mark
Anonymous
January 14, 2005 2:15:47 AM

Archived from groups: rec.photo.digital (More info?)

Jimmy Smith wrote:
> What do they mean when they refer to 1:1 magnification on a Canon 100mm
> macro f2.8?
>
> It seems like a 1:1 ration wouldn't give any magnification so what's the
> deal?
>
> Jimmy
>
>
Any lens that can focus at a distance equal to its focal length will
give a 1:1 ratio.
That means, Image Size (on the sensor) = Subject Size.
The problem with most regular lenses in regular mounts is that they
cannot focus at distances as short as their focal lengths. But 1:1 Macro
lenses are designed to focus as close as their focal length. e.g. a 50
mm Macro wil give a 1:1 image size when focused at 50 mm or ~2 inches
from the subject.
Bob Williams
Related resources
Anonymous
January 14, 2005 4:41:29 AM

Archived from groups: rec.photo.digital (More info?)

Hint: Do you print your images in post stamp format? And, if you are using a
computer monitor, how large is your screen? Is it just the size of your
camera's image sensor? A super tiny screen perhaps?

"Jimmy Smith" <nospam@pleaseno.more> wrote in message
news:E%EFd.25147$vM4.23243@bignews3.bellsouth.net...
> What do they mean when they refer to 1:1 magnification on a Canon 100mm
> macro f2.8?
>
> It seems like a 1:1 ration wouldn't give any magnification so what's the
> deal?
>
> Jimmy
>
>
Anonymous
January 14, 2005 4:41:30 AM

Archived from groups: rec.photo.digital (More info?)

GTO wrote:
> Hint: Do you print your images in post stamp format? And, if you are
> using a computer monitor, how large is your screen? Is it just the
> size of your camera's image sensor? A super tiny screen perhaps?
>
> "Jimmy Smith" <nospam@pleaseno.more> wrote in message
> news:E%EFd.25147$vM4.23243@bignews3.bellsouth.net...
>> What do they mean when they refer to 1:1 magnification on a Canon
>> 100mm macro f2.8?
>>
>> It seems like a 1:1 ration wouldn't give any magnification so what's
>> the deal?
>>
>> Jimmy

This would mean that the image of your subject would appear on your sensor
the same size.
A 1/2 inch object would be 1/2 inch (on the sensor).

Ken.


--
http://www.rupert.net/~solar
Return address supplied by 'spammotel'
http://www.spammotel.com
Anonymous
January 14, 2005 7:10:40 PM

Archived from groups: rec.photo.digital (More info?)

On Thu, 13 Jan 2005 20:14:30 -0500, "Jimmy Smith"
<nospam@pleaseno.more> wrote:

>What do they mean when they refer to 1:1 magnification on a Canon 100mm
>macro f2.8?
>
>It seems like a 1:1 ration wouldn't give any magnification so what's the
>deal?
>
>Jimmy
>

In the film world, 1:1 means that the subject will be the same size on
the negative as in real life. ie. If you took a 1:1 image of a
penny, you could lay a real penny on the negative and it would
precisely match the image,

I don't know how this relates to a CCD environment. I would assume
the same. ie. The same size on the CCD as in real life.
Anonymous
January 14, 2005 8:32:01 PM

Archived from groups: rec.photo.digital (More info?)

Close ... but I think your "math" is a little off.

Your statement "... Any lens that can focus at a distance equal to its
focal length will
give a 1:1 ratio. ..." is incorrect.

If you use the proper formula, you will find that the image will be the
exact size as the subject when

The distance from the subject image to the lens nodal point is equal to the
distance from the lens' nodal point to the film plane ... which is equal to
*twice* the focal length.

See ... for example ...:
http://www.graflex.org/lenses/lens-faq.html
http://www.photo.net/learn/optics/lensTutorial
http://www.zeiss.de/C12567A8003B58B9/allBySubject/15C75...
054968D

and several hundred other sites that present the basic lens equation(s).
Anonymous
January 14, 2005 8:32:02 PM

Archived from groups: rec.photo.digital (More info?)

RSD99 wrote:
> Close ... but I think your "math" is a little off.
>
> Your statement "... Any lens that can focus at a distance equal to its
> focal length will
> give a 1:1 ratio. ..." is incorrect.
>
> If you use the proper formula, you will find that the image will be the
> exact size as the subject when
>
> The distance from the subject image to the lens nodal point is equal to the
> distance from the lens' nodal point to the film plane ... which is equal to
> *twice* the focal length.
>
> See ... for example ...:
> http://www.graflex.org/lenses/lens-faq.html
> http://www.photo.net/learn/optics/lensTutorial
> http://www.zeiss.de/C12567A8003B58B9/allBySubject/15C75...
> 054968D
>
> and several hundred other sites that present the basic lens equations



Mea Culpa!
You are absolutely correct.
I should have said that, "any lens that can focus at TWICE its focal
length will give a 1:1 magnification."
Thanks for the heads up.
Bob Williams
Anonymous
January 14, 2005 11:23:10 PM

Archived from groups: rec.photo.digital (More info?)

>>What do they mean when they refer to 1:1 magnification on a Canon 100mm
>>macro f2.8? It seems like a 1:1 ration wouldn't give any magnification so
what's the deal?
>>Jimmy

>In the film world, 1:1 means that the subject will be the same size on
>the negative as in real life. ie. If you took a 1:1 image of a
>penny, you could lay a real penny on the negative and it would
>precisely match the image,
To add to the last reply, I used to have a macro lens that only had a 0.5
magnification. The 1.0 mag. was the best at that time. The only way to best
that was to use a bellows and assemble the lens backwards. Possinly, the 1.0
mag. is still the best macro lens you can get.
Lynn
Anonymous
January 15, 2005 10:07:16 AM

Archived from groups: rec.photo.digital (More info?)

RSD99 wrote:
> Close ... but I think your "math" is a little off.
>
> Your statement "... Any lens that can focus at a distance equal to its
> focal length will
> give a 1:1 ratio. ..." is incorrect.
>
> If you use the proper formula, you will find that the image will be the
> exact size as the subject when
>
> The distance from the subject image to the lens nodal point is equal to the
> distance from the lens' nodal point to the film plane ... which is equal to
> *twice* the focal length.
>
> See ... for example ...:
> http://www.graflex.org/lenses/lens-faq.html
> http://www.photo.net/learn/optics/lensTutorial
> http://www.zeiss.de/C12567A8003B58B9/allBySubject/15C75...
> 054968D
>
> and several hundred other sites that present the basic lens equation(s).
>
>
>

Ha! Finally somebody that knows the standard definition.

Also what is it about 1:1 that do people not understand?
It's a ratio. $1 for 1 orange, 1 foot high for each 1 foot
forward, etc. With a lens what else can it mean but the
image is the same size as the object?

Why do people speculate about definitions instead of just
reading about them in an authoritative publication.
Anonymous
January 15, 2005 2:34:27 PM

Archived from groups: rec.photo.digital (More info?)

George E. Cawthon wrote:
> RSD99 wrote:
>> Close ... but I think your "math" is a little off.
>>
>> Your statement "... Any lens that can focus at a distance equal to
>> its focal length will
>> give a 1:1 ratio. ..." is incorrect.
>>
>> If you use the proper formula, you will find that the image will be
>> the exact size as the subject when
>>
>> The distance from the subject image to the lens nodal point is equal
>> to the distance from the lens' nodal point to the film plane ...
>> which is equal to *twice* the focal length.
>>
>> See ... for example ...:
>> http://www.graflex.org/lenses/lens-faq.html
>> http://www.photo.net/learn/optics/lensTutorial
>> http://www.zeiss.de/C12567A8003B58B9/allBySubject/15C75...
>> 054968D
>>
>> and several hundred other sites that present the basic lens
>> equation(s).
>
> Ha! Finally somebody that knows the standard definition.
>
> Also what is it about 1:1 that do people not understand?
> It's a ratio. $1 for 1 orange, 1 foot high for each 1 foot
> forward, etc. With a lens what else can it mean but the
> image is the same size as the object?
>
> Why do people speculate about definitions instead of just
> reading about them in an authoritative publication.

They need a sagacious guru to lead them.


--
Frank ess
Anonymous
January 18, 2005 7:59:23 PM

Archived from groups: rec.photo.digital (More info?)

George E. Cawthon <GeorgeC-Boise@worldnet.att.net> wrote:
>RSD99 wrote:
>> Close ... but I think your "math" is a little off.
>>
>> Your statement "... Any lens that can focus at a distance equal to its
>> focal length will
>> give a 1:1 ratio. ..." is incorrect.
>>
>> If you use the proper formula, you will find that the image will be the
>> exact size as the subject when
>>
>> The distance from the subject image to the lens nodal point is equal to the
>> distance from the lens' nodal point to the film plane ... which is equal to
>> *twice* the focal length.
>>
>> See ... for example ...:
>> http://www.graflex.org/lenses/lens-faq.html
>> http://www.photo.net/learn/optics/lensTutorial
>> http://www.zeiss.de/C12567A8003B58B9/allBySubject/15C75...
>> 054968D
>>
>> and several hundred other sites that present the basic lens equation(s).
>>
>>
>>

>Ha! Finally somebody that knows the standard definition.

>Also what is it about 1:1 that do people not understand?
>It's a ratio. $1 for 1 orange, 1 foot high for each 1 foot
>forward, etc. With a lens what else can it mean but the
>image is the same size as the object?

>Why do people speculate about definitions instead of just
>reading about them in an authoritative publication.

Because in the good old days the image size was fixed. It
was film and the negative had an intrinsic size.

What is the size of my 6.1 megapixel image? Does it have any
relationship to the size of the sensor?

You see, the old definition is inadequate in the digital
world.

---- Paul J. Gans
Anonymous
January 18, 2005 7:59:24 PM

Archived from groups: rec.photo.digital (More info?)

In article <csjf9b$7p4$6@reader2.panix.com>,
Paul J Gans <gans@panix.com> wrote:

> You see, the old definition is inadequate in the digital
> world.

What is inadequate?

the reproduction ratio definition is constant regardless of film/sensor
size. It is the ratio of the object to it's size on film/sensor.

If a 1.5" long object fill a 35mm frame it is 1:1. If that same object
is 1.5" long on an 8x10 piece of film it is still 1:1.

If it is .75" long on any material it is 1:2. Etc.

The imaging medium does not matter except that you can not reproduce an
object larger then the film/sensor at 1:1 in one shot.

--
To reply no_ HPMarketing Corp.
Anonymous
January 18, 2005 8:23:40 PM

Archived from groups: rec.photo.digital (More info?)

"Paul J Gans" posted:
"...
You see, the old definition is inadequate in the digital world.
...."

Wrong ... the old definitions are perfectly adequate and complete .... and
they have not been changed one bit by the "digital world."

The basic problem appears to be that you just do not understand this
"digital world" that you so blithely banter about, and are trying to think
in terms of dimensionless "megapixel(s)" ... when you should be thinking in
terms of "images." This "assumption" is confirmed by your second question
.... "... Does it have any relationship to the size of the sensor? ..."

One-to-one ... or 1:1 ... means the same thing in 35 mm photography, large
format sheet film photography, *and* in digital photography. It means that
the lens is capable of focusing an image at the exact size of the object on
the image sensing/capture device ... whether it is a piece of film (and
**any** size of film) or a photovoltaic sensor array.

What is so hard about that?
Anonymous
January 18, 2005 9:23:17 PM

Archived from groups: rec.photo.digital (More info?)

In article <wCbHd.8554$5t2.7751@trnddc01>, rsdwla.NOSPAM@gte.net says...
> "Paul J Gans" posted:
> "...
> You see, the old definition is inadequate in the digital world.
> ..."
>
> Wrong ... the old definitions are perfectly adequate and complete .... and
> they have not been changed one bit by the "digital world."
>
> The basic problem appears to be that you just do not understand this
> "digital world" that you so blithely banter about, and are trying to think
> in terms of dimensionless "megapixel(s)" ... when you should be thinking in
> terms of "images." This "assumption" is confirmed by your second question
> ... "... Does it have any relationship to the size of the sensor? ..."
>
> One-to-one ... or 1:1 ... means the same thing in 35 mm photography, large
> format sheet film photography, *and* in digital photography. It means that
> the lens is capable of focusing an image at the exact size of the object on
> the image sensing/capture device ... whether it is a piece of film (and
> **any** size of film) or a photovoltaic sensor array.
>
> What is so hard about that?
>
In the film world, the 'sensor size' (I.e. negative size) had relevance
since that was what your image was - a physical size.
In the digital world, the sensor size is no longer as relevant since it
is simply one part of the chain that goes into making the final image.
The final image has no size, as it is a collection of pixels.

What is so hard about that?
Anonymous
January 18, 2005 10:53:54 PM

Archived from groups: rec.photo.digital (More info?)

"Graeme Cogger" <gcogger@bigSPAMfoot.com> wrote in message
news:9pGdnWIXn6stznDcRVnyuA@pipex.net...
> In article <wCbHd.8554$5t2.7751@trnddc01>, rsdwla.NOSPAM@gte.net says...
>> "Paul J Gans" posted:
>> "...
>> You see, the old definition is inadequate in the digital world.
>> ..."
>>
>> Wrong ... the old definitions are perfectly adequate and complete ....
>> and
>> they have not been changed one bit by the "digital world."
>>
>> The basic problem appears to be that you just do not understand this
>> "digital world" that you so blithely banter about, and are trying to
>> think
>> in terms of dimensionless "megapixel(s)" ... when you should be thinking
>> in
>> terms of "images." This "assumption" is confirmed by your second question
>> ... "... Does it have any relationship to the size of the sensor? ..."
>>
>> One-to-one ... or 1:1 ... means the same thing in 35 mm photography,
>> large
>> format sheet film photography, *and* in digital photography. It means
>> that
>> the lens is capable of focusing an image at the exact size of the object
>> on
>> the image sensing/capture device ... whether it is a piece of film (and
>> **any** size of film) or a photovoltaic sensor array.
>>
>> What is so hard about that?
>>
> In the film world, the 'sensor size' (I.e. negative size) had relevance
> since that was what your image was - a physical size.
> In the digital world, the sensor size is no longer as relevant since it
> is simply one part of the chain that goes into making the final image.
> The final image has no size, as it is a collection of pixels.
>
> What is so hard about that?

So, an electronic image sensor is somehow dimensionless, whereas a bit of
film has a finite physical size?
And a film image was never the start of a chain that went into making the
final image?(and could of course, produce an image bigger or small than the
original object)

Is that what you're saying?

Macro means target 3mm across, covers 3mm of the film or CCD.
Simple, not at all hard.

Deep.
Anonymous
January 18, 2005 11:31:56 PM

Archived from groups: rec.photo.digital (More info?)

Wrong.




"Graeme Cogger" <gcogger@bigSPAMfoot.com> wrote in message
news:9pGdnWIXn6stznDcRVnyuA@pipex.net...
>
> In the film world, the 'sensor size' (I.e. negative size) had relevance
> since that was what your image was - a physical size.
> In the digital world, the sensor size is no longer as relevant since it
> is simply one part of the chain that goes into making the final image.
> The final image has no size, as it is a collection of pixels.
>
> What is so hard about that?
Anonymous
January 18, 2005 11:47:19 PM

Archived from groups: rec.photo.digital (More info?)

In article <0neHd.2461$J6.1283@trnddc02>, rsdwla.NOSPAM@gte.net says...
> Wrong.
>
>

A compelling argument...

>
>
> "Graeme Cogger" <gcogger@bigSPAMfoot.com> wrote in message
> news:9pGdnWIXn6stznDcRVnyuA@pipex.net...
> >
> > In the film world, the 'sensor size' (I.e. negative size) had relevance
> > since that was what your image was - a physical size.
> > In the digital world, the sensor size is no longer as relevant since it
> > is simply one part of the chain that goes into making the final image.
> > The final image has no size, as it is a collection of pixels.
> >
> > What is so hard about that?
>
>
>
Anonymous
January 19, 2005 12:01:16 AM

Archived from groups: rec.photo.digital (More info?)

In article <csjpgi$9ga$1@titan.btinternet.com>, DeepReset@hotmail.com
says...
> "Graeme Cogger" <gcogger@bigSPAMfoot.com> wrote in message
> news:9pGdnWIXn6stznDcRVnyuA@pipex.net...
> > In article <wCbHd.8554$5t2.7751@trnddc01>, rsdwla.NOSPAM@gte.net says...
> >> "Paul J Gans" posted:
> >> "...
> >> You see, the old definition is inadequate in the digital world.
> >> ..."
> >>
> >> Wrong ... the old definitions are perfectly adequate and complete ....
> >> and
> >> they have not been changed one bit by the "digital world."
> >>
> >> The basic problem appears to be that you just do not understand this
> >> "digital world" that you so blithely banter about, and are trying to
> >> think
> >> in terms of dimensionless "megapixel(s)" ... when you should be thinking
> >> in
> >> terms of "images." This "assumption" is confirmed by your second question
> >> ... "... Does it have any relationship to the size of the sensor? ..."
> >>
> >> One-to-one ... or 1:1 ... means the same thing in 35 mm photography,
> >> large
> >> format sheet film photography, *and* in digital photography. It means
> >> that
> >> the lens is capable of focusing an image at the exact size of the object
> >> on
> >> the image sensing/capture device ... whether it is a piece of film (and
> >> **any** size of film) or a photovoltaic sensor array.
> >>
> >> What is so hard about that?
> >>
> > In the film world, the 'sensor size' (I.e. negative size) had relevance
> > since that was what your image was - a physical size.
> > In the digital world, the sensor size is no longer as relevant since it
> > is simply one part of the chain that goes into making the final image.
> > The final image has no size, as it is a collection of pixels.
> >
> > What is so hard about that?
>
> So, an electronic image sensor is somehow dimensionless, whereas a bit of
> film has a finite physical size?

A sensor has size, but is not the image. The image is what is stored on
a flash card, and is created from the subject, lens and sensor in
combination.

> And a film image was never the start of a chain that went into making the
> final image?(and could of course, produce an image bigger or small than the
> original object)
>
> Is that what you're saying?
>

Of course the image on film is part of a chain. That's why I believe
the 1:1 macro definition is nothing special even on film - it's just a
convenient measure to allow you to compare lenses. If you say that a
lens will do 1:1 macro (on a 35mm camera), you know that an object 35mm
across will fill the frame. That's all it's useful for, and you need to
specify the film size before you know what a 1:1 ratio will do to the
final (e.g. printed) image.
On a digital camera, to take the same picture, the 35mm object should be
shrunk to (e.g. on a Nikon D70) 35 / 1.5 = 23mm. So to take the SAME
picture on a Nikon D70, you don't want a 1:1 ratio at the sensor.

> Macro means target 3mm across, covers 3mm of the film or CCD.
> Simple, not at all hard.
>

And also pretty useless information without talking about the
sensor/film size.

> Deep.
>
>
>
Anonymous
January 19, 2005 12:17:46 AM

Archived from groups: rec.photo.digital (More info?)

"RSD99" <rsdwla.NOSPAM@gte.net> wrote in message
news:0neHd.2461$J6.1283@trnddc02...
> Wrong.

Well I guess that settles that!



> "Graeme Cogger" <gcogger@bigSPAMfoot.com> wrote in message
> news:9pGdnWIXn6stznDcRVnyuA@pipex.net...
> >
> > In the film world, the 'sensor size' (I.e. negative size) had relevance
> > since that was what your image was - a physical size.
> > In the digital world, the sensor size is no longer as relevant since it
> > is simply one part of the chain that goes into making the final image.
> > The final image has no size, as it is a collection of pixels.
> >
> > What is so hard about that?
>
>
Anonymous
January 19, 2005 2:57:17 AM

Archived from groups: rec.photo.digital (More info?)

Graeme Cogger <gcogger@bigspamfoot.com> wrote:
>
> A sensor has size, but is not the image. The image is what is stored on
> a flash card, and is created from the subject, lens and sensor in
> combination.

When we are talking about optics, the image is the optical
image projected on the sensor or film.

>
>
> Of course the image on film is part of a chain. That's why I believe
> the 1:1 macro definition is nothing special even on film - it's just a
> convenient measure to allow you to compare lenses. If you say that a
> lens will do 1:1 macro (on a 35mm camera), you know that an object 35mm
> across will fill the frame. That's all it's useful for,

No. It is useful for quite a bit more than that. If you know
the reproduction ratio you want and the actual focal length
of your lens, you can adjust the bellows (or add extension rings)
to get that reproduction ratio. It will also tell you how far the
object should be in front of the lens.

The reproduction ratio will also tell you how much extra exposure
you need because of the extra lens extension. This is not needed
if you are depending on the meter built into the camera, but it
is often useful to work with a separate meter, or to do calculations
with flash guide numbers. If you know the reproduction ratio,
you can get the exposure right the first time.

Peter.
--
pirwin@ktb.net
Anonymous
January 19, 2005 12:39:30 PM

Archived from groups: rec.photo.digital (More info?)

Graeme Cogger wrote:
>
> In the film world, the 'sensor size' (I.e. negative size) had relevance
> since that was what your image was - a physical size.
> In the digital world, the sensor size is no longer as relevant since it
> is simply one part of the chain that goes into making the final image.
> The final image has no size, as it is a collection of pixels.
>


I would agree with this only with older large format photography. With
35mm, however, virtually no one uses contact prints for anything other
than proofing. When people make prints, they virtually always enlarge
them. Thus, I see no difference between 35mm and digital as far as the
importance of format size, with the exception that bigger is always
better :-)
Anonymous
January 20, 2005 11:02:26 AM

Archived from groups: rec.photo.digital (More info?)

Jimmy Smith wrote:

> It seems like a 1:1 ration wouldn't give any magnification
> so what's the deal?

Think about a conventional lens. It also does not magnify, but
reduces. The image of a 6 foot person or a tall building is just a
fraction of an inch at the sensor. Yet the term magnification applies,
whether it is greater than 1, less than 1, or equal to 1.

Compared to a conventional lens, a magnification of a 1:1 is extremely
large.
Anonymous
January 22, 2005 9:16:46 PM

Archived from groups: rec.photo.digital (More info?)

Deep Reset <DeepReset@hotmail.com> wrote:

> So, an electronic image sensor is somehow dimensionless, whereas a bit of
> film has a finite physical size?

Maybe the original statement should be rephrased in that with digital
photography the sensor size is "relative" rather than "absolute". With
film, "full frame" means 24x36mm. In the digital world, it can mean any
number of sizes.

Ton
Anonymous
January 22, 2005 9:19:11 PM

Archived from groups: rec.photo.digital (More info?)

Graeme Cogger <gcogger@bigSPAMfoot.com> wrote:

> Of course the image on film is part of a chain. That's why I believe
> the 1:1 macro definition is nothing special even on film - it's just a
> convenient measure to allow you to compare lenses.

Well, it used to be quite relevant in slide duplication.

Ton
Anonymous
January 22, 2005 9:28:12 PM

Archived from groups: rec.photo.digital (More info?)

LLutton <llutton@aol.com> wrote:

> >>What do they mean when they refer to 1:1 magnification on a Canon 100mm
> >>macro f2.8? It seems like a 1:1 ration wouldn't give any magnification so
> what's the deal?
> >>Jimmy
>
> >In the film world, 1:1 means that the subject will be the same size on
> >the negative as in real life. ie. If you took a 1:1 image of a
> >penny, you could lay a real penny on the negative and it would
> >precisely match the image,
> To add to the last reply, I used to have a macro lens that only had a 0.5
> magnification. The 1.0 mag. was the best at that time. The only way to best
> that was to use a bellows and assemble the lens backwards. Possinly, the 1.0
> mag. is still the best macro lens you can get.
> Lynn

There's an interesting statement on the Oly website, concerning their
50/2.0 macro for the E-system. They claim that without macro extender
the lens is capable of 0.52x maginification, which is then claimed to be
the equivalent of 1.04x in a 35mm camera.

Ton
Anonymous
January 30, 2005 1:48:30 AM

Archived from groups: rec.photo.digital (More info?)

"Ton Maas" <tonmaas@xs4all.nl> wrote in message
news:1gqsyoa.1donej81jt7q0sN%tonmaas@xs4all.nl...
> Deep Reset <DeepReset@hotmail.com> wrote:
>
>> So, an electronic image sensor is somehow dimensionless, whereas a bit of
>> film has a finite physical size?
>
> Maybe the original statement should be rephrased in that with digital
> photography the sensor size is "relative" rather than "absolute". With
> film, "full frame" means 24x36mm. In the digital world, it can mean any
> number of sizes.

How so?

1:1 means "the thing you are looking is x mm big in real life, and occupies
x mm or film/sensor space in the camera.

I really don't get that digital is somehow different to film.

Maybe you can explain it better.

Deep.
Anonymous
January 30, 2005 7:43:31 AM

Archived from groups: rec.photo.digital (More info?)

Deep Reset <DeepReset@hotmail.com> wrote:

: "Ton Maas" <tonmaas@xs4all.nl> wrote in message
: news:1gqsyoa.1donej81jt7q0sN%tonmaas@xs4all.nl...
: > Deep Reset <DeepReset@hotmail.com> wrote:
: >
: >> So, an electronic image sensor is somehow dimensionless, whereas a bit of
: >> film has a finite physical size?
: >
: > Maybe the original statement should be rephrased in that with digital
: > photography the sensor size is "relative" rather than "absolute". With
: > film, "full frame" means 24x36mm. In the digital world, it can mean any
: > number of sizes.

: How so?

: 1:1 means "the thing you are looking is x mm big in real life, and occupies
: x mm or film/sensor space in the camera.

: I really don't get that digital is somehow different to film.

: Maybe you can explain it better.

Let me give this a shot. With film, the product (prior to printing and
other post processing) is an actual physical object. And thus a 1:1 ratio
between the size of the object being photographed and the size of the
image on the film is the same length. And if you are talking about the
image being sensed on the digital sensor, the same relationship holds
true. But digital photos are different due to the fact that the end
product of a digital photo is a series of data bits that will then be
"assumed" by display programs to be representing an image somewhat larger
than the physical sensor dimensions. And since each brand of camera tends
to use different sensors, and uses different amounts of the image space of
that sensor in widely variable ways, the digital "image size" differs from
camera to camera. So without lots of camera specific data, it could be
difficult to convert the specific data in the same way as the 1:1 ratio is
resolved with film.

But for those of us who are used to the designations from the long ago
days of film, we use the designation "1:1" to aproximate the desired
outcome.

Did this help?

Randy

==========
Randy Berbaum
Champaign, IL
Anonymous
January 30, 2005 11:53:14 PM

Archived from groups: rec.photo.digital (More info?)

"Randy Berbaum" <rberbaum@bluestem.prairienet.org> wrote in message
news:ctholj$3jj$1@wildfire.prairienet.org...
> Deep Reset <DeepReset@hotmail.com> wrote:
>
> : "Ton Maas" <tonmaas@xs4all.nl> wrote in message
> : news:1gqsyoa.1donej81jt7q0sN%tonmaas@xs4all.nl...
> : > Deep Reset <DeepReset@hotmail.com> wrote:
> : >
> : >> So, an electronic image sensor is somehow dimensionless, whereas a
> bit of
> : >> film has a finite physical size?
> : >
> : > Maybe the original statement should be rephrased in that with digital
> : > photography the sensor size is "relative" rather than "absolute". With
> : > film, "full frame" means 24x36mm. In the digital world, it can mean
> any
> : > number of sizes.
>
> : How so?
>
> : 1:1 means "the thing you are looking is x mm big in real life, and
> occupies
> : x mm or film/sensor space in the camera.
>
> : I really don't get that digital is somehow different to film.
>
> : Maybe you can explain it better.
>
> Let me give this a shot. With film, the product (prior to printing and
> other post processing) is an actual physical object. And thus a 1:1 ratio
> between the size of the object being photographed and the size of the
> image on the film is the same length. And if you are talking about the
> image being sensed on the digital sensor, the same relationship holds
> true. But digital photos are different due to the fact that the end
> product of a digital photo is a series of data bits that will then be
> "assumed" by display programs to be representing an image somewhat larger
> than the physical sensor dimensions. And since each brand of camera tends
> to use different sensors, and uses different amounts of the image space of
> that sensor in widely variable ways, the digital "image size" differs from
> camera to camera. So without lots of camera specific data, it could be
> difficult to convert the specific data in the same way as the 1:1 ratio is
> resolved with film.
>
> But for those of us who are used to the designations from the long ago
> days of film, we use the designation "1:1" to aproximate the desired
> outcome.
>
> Did this help?

No, it didn't.

Taking a ratio is precisely the method one uses to remove the dependence on
physical units; that's what ratios do.
Its a form of normalisation, so removes the need to know the size of the
sensor.
So quoting a 1:1 reproduction ratio says that the image of the thing you
recorded is the same size as the object represented in the image, whether
you took the shot with a 1/2.7" P&S, an APS-sized CCD, a 35mm film, a medium
format, 10"x 8" plate camera or...a photocopier.

Bringing bits and bytes and display program assumptions into the argument is
a sideshow - we used to display our slides at whatever size we wanted or
were comfortable with; we used enlargers to print to whatever size we wanted
or the original image quality would allow.

Deep.
!