Why do only primes have macro

In article <dintal$6l0$1@reader01.singnet.com.sg>,
"kctan" <kcpps.TakeThisOut@singnet.com.sg> wrote:

> Therefore, very close up photography
> is not feasible using large format camera.
>

Nonsense. It is done all the time.

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 >> Stay informed about: Why do only primes have macro 

DoN. Nichols wrote:

> According to Paul Furman <paul- DeleteThis @-edgehill.net>:
>
>>DoN. Nichols wrote:
>>
>>>According to Paul Furman <paul- DeleteThis @-edgehill.net>:
>>>
>>>>Extension tubes limit the light
>>>
>>Hmm, wouldn't this be true no matter how you enlarge the image, it gets
>>fainter as you make it bigger. I can't understand why closeup lenses do
>>not effect exposure, it's simply something I've read and repeated.
>
> Actually, it is quite simple.
>
> When you move the lens farther from the sensor or film, the
> physical diameter of the aperture remains the same,
> and the f-number [increases giving a slower lens]...
>...
> When you add a close-up lens in front of the prime lens, you
> don't change the distance from the diaphragm to the focal plane. You
> change the power of the lens cluster in front of the diaphragm, without
> changing the location of the aperture.
>
> IIRC, 1:1 magnification ratio is to be found at double the focal
> length of the lens, or the 100mm point [for a 50mm lens].


OK, so extension tubes really do require longer exposures than screw-on
closeup lenses.
 >> Stay informed about: Why do only primes have macro 

In article <xySsIyERk$TDFwbO@newbrain.demon.co.uk>,
Prometheus <Prometheus.DeleteThis@127.0.0.1> wrote:

> You will find that microscopes start at about 25:1.

Depends on the microscope. Some stereo scopes seem to start at lower
magnifications.

Linhof used to offer both a Micro Tube lensboard with built-in 0 shutter
for use with any society drawtube microscope with their 2x3" through
8x10" cameras as well as a Macro Tube board with 0 shutter for the
Luminar and then later M Componon and Apo Rodagon D lenses. With the 57
Technika and a 16mm Luminar 40:1 was easily obtainable on a copy stand.
This is well into what many call photomicrography yet it was easily done
with a stedy copy stand, full extension, a 16 mm Luminar and the proper
lens board adapters.

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 >> Stay informed about: Why do only primes have macro 

In article <A9WdnY62_bGsedfeRVn-pA RemoveThis @speakeasy.net>, Paul Furman
<paul- RemoveThis @-edgehill.net> writes
>David Littlewood wrote:
>
>> In article <8LadnSWn-MwBKdTenZ2dnUVZ_sidnZ2d RemoveThis @speakeasy.net>, Paul
>>Furman <paul- RemoveThis @-edgehill.net> writes
>>
>>> DoN. Nichols wrote:
>>>
>>>> According to Paul Furman <paul- RemoveThis @-edgehill.net>:
>>>>
>>>>> Extension tubes limit the light
>>>>
>>>> Well ... they really spread the image (and thus the light) over
>>>> a larger area -- of which only that which strikes the sensor (or film)
>>>
>>>
>>>
>>> Hmm, wouldn't this be true no matter how you enlarge the image, it
>>>gets fainter as you make it bigger. I can't understand why closeup
>>>lenses do not effect exposure, it's simply something I've read and
>>>repeated.
>>>
>> AIUI - and I haven't had time to check right now - they reduce the
>>focal length whilst not affecting the absolute aperture. Thus the
>>relative aperture increases. However, as image magnification has been
>>increased, the effective aperture (N' = N*(1+m), i.e. aperture
>>adjusted for the effect of increased distance from lens to
>>film/sensor, is reduced. This seems to all cancel out.
>> Sorry if this is a bit hasty, just off on a trip.
>
>
>OK so there really isn't less light with extension tubes, it's just
>that the metering gets screwed up so you use exposure compensation to
>overcome and it's not a big deal?

We were discussing supplementary close-up lenses, not extension tubes;
the two work in quite different ways.

> But no matter how you get there, 1:1 is going to have less light. It's
>the same amount of light spread over the same area. Perhaps a trivial
>loss through more pieces of glass.
>
You are ignoring the effect of the increase in aperture by using a
close-up lens.

David
--
David Littlewood
 >> Stay informed about: Why do only primes have macro 

David Littlewood wrote:

> <paul- DeleteThis @-edgehill.net> writes
>
>> David Littlewood wrote:
>>
>>> Furman <paul- DeleteThis @-edgehill.net> writes
>>>
>>>> DoN. Nichols wrote:
>>>>
>>>>> According to Paul Furman <paul- DeleteThis @-edgehill.net>:
>>>>>
>>>>>> Extension tubes limit the light
>>>>>
>>>>> Well ... they really spread the image (and thus the light) over
>>>>> a larger area -- of which only that which strikes the sensor (or film)
>>>>
>>>> Hmm, wouldn't this be true no matter how you enlarge the image, it
>>>> gets fainter as you make it bigger. I can't understand why closeup
>>>> lenses do not effect exposure, it's simply something I've read and
>>>> repeated.
>>>>
>>> AIUI - and I haven't had time to check right now - they reduce the
>>> focal length whilst not affecting the absolute aperture. Thus the
>>> relative aperture increases. However, as image magnification has been
>>> increased, the effective aperture (N' = N*(1+m), i.e. aperture
>>> adjusted for the effect of increased distance from lens to
>>> film/sensor, is reduced. This seems to all cancel out.
>>> Sorry if this is a bit hasty, just off on a trip.
>>
>> OK so there really isn't less light with extension tubes, it's just
>> that the metering gets screwed up so you use exposure compensation to
>> overcome and it's not a big deal?
>
> We were discussing supplementary close-up lenses, not extension tubes;
> the two work in quite different ways.
>
>> But no matter how you get there, 1:1 is going to have less light. It's
>> the same amount of light spread over the same area. Perhaps a trivial
>> loss through more pieces of glass.
>>
> You are ignoring the effect of the increase in aperture by using a
> close-up lens.

I'm still unclear if there is a pseudo aperture change or what. See
above for my clarification of Don's comments regarding extension tubes
increase aperture number. Am I correct in my conclusion there that
exposure time/shutter speed is longer with extension tubes than closeup
lenses?
 >> Stay informed about: Why do only primes have macro 

In article <dihi490mrk DeleteThis @news3.newsguy.com>, DoN. Nichols
<dnichols DeleteThis @d-and-d.com> writes
> But -- past a certain point, instead of being macrophotograpy,
>it becomes microphotography, as when you have the camera body mounted
>in place of an eyepiece on a microscope.
>
Photomacrography and photomicrography please, Don.

David
--
David Littlewood
 >> Stay informed about: Why do only primes have macro 

In article <diej8b$qd8$1@mawar.singnet.com.sg>, kctan
<kcpps RemoveThis @singnet.com.sg> writes
>Lenses normally designed for recording image at max 1/10th the size of the
>object and this is the closest distant in focus. To get more than this
>magnification and in focus, the lens has to be extended but causes light
>lost. Macro lens is designed to deny this extension and yet get a max
>magnification of 1:2 i.e 1/2 life size or 1/2 the object size. To get even
>more magification, an extension ring or tube or a bellow got to be fitted in
>between the lens and camera body but exposure compensation is needed due to
>light lost.

I think we got that bit.

> Therefore, photography work having magnification more than 0.1X
>is known as Macro photography.
>
Not according to serious workers and standard reference books. Only to
advertisers.

David
--
David Littlewood
 >> Stay informed about: Why do only primes have macro 

Paul Furman <paul- RemoveThis @-edgehill.net> wrote:
>
> OK, so extension tubes really do require longer exposures than screw-on
> closeup lenses.

There is no free lunch.

A 50mm f/2 lens with a +2 diopter close-up lens is essentially
the same as a 45mm f/1.8 lens with a 5mm extension tube.

The primary lens plus closeup lens combination produces
a lens of shorter focal length. Since the lens barrel
remains the same, it acts as an extension tube. Since
the physical aperture of the lens is also unchanged
the combination has a faster relative aperture relative
to its combined focal length. Since the lens is racked
out further the effective aperture is reduced to the
same as the relative aperture at infinity of the prime lens.

Hope this helps,

Peter.
--
pirwin RemoveThis @ktb.net
 >> Stay informed about: Why do only primes have macro 

In article <diot6g$fgp$1@dns.ktb.net>, Peter Irwin <pirwin.DeleteThis@ktb.net>
wrote:

> Paul Furman <paul-.DeleteThis@-edgehill.net> wrote:
> >
> > OK, so extension tubes really do require longer exposures than screw-on
> > closeup lenses.
>
> There is no free lunch.
>
> A 50mm f/2 lens with a +2 diopter close-up lens is essentially
> the same as a 45mm f/1.8 lens with a 5mm extension tube.
>
> The primary lens plus closeup lens combination produces
> a lens of shorter focal length. Since the lens barrel
> remains the same, it acts as an extension tube. Since
> the physical aperture of the lens is also unchanged
> the combination has a faster relative aperture relative
> to its combined focal length. Since the lens is racked
> out further the effective aperture is reduced to the
> same as the relative aperture at infinity of the prime lens.
>
> Hope this helps,
>
> Peter.

You neglected to mention the loss of resolution, especially around the
edges, with CU lenses. Now if you were using Achromat + lenses there
would be negligible effect on resolution, none on exposure but they are
usually +4 and above.

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In article <8JFVc$BRr9TDFwZn@dlittlewood.co.uk>, David Littlewood
<david RemoveThis @nospam.demon.co.uk> writes
>In article <dihi490mrk RemoveThis @news3.newsguy.com>, DoN. Nichols
><dnichols RemoveThis @d-and-d.com> writes
>> But -- past a certain point, instead of being macrophotograpy,
>>it becomes microphotography, as when you have the camera body mounted
>>in place of an eyepiece on a microscope.
>>
>Photomacrography and photomicrography please, Don.
>
>David
I have seen:
Photomicrography images is much larger than life size (bacteria).
Photomacrography images is equal or slightly larger than life size.
Macrophotograpy images is lightly smaller than life size.
Microphotography images is much smaller than life size (landscapes).
--
Ian G8ILZ
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Prometheus <Prometheus RemoveThis @127.0.0.1> wrote:
>>
>>David
> I have seen:
> Photomicrography images is much larger than life size (bacteria).
> Photomacrography images is equal or slightly larger than life size.
> Macrophotograpy images is lightly smaller than life size.
> Microphotography images is much smaller than life size
> (landscapes).

Microphotography normally means producing microfilm, microdots
or really tiny photographs.

Photomicrography normally means photography through a microscope.

Photomacrography means photography where the image side is
equal or larger in size than the object side.

Macrophotography is generally used as a synonym for photomacrography,
but perhaps with a somewhat looser definition. Macrophotography
was also occasionally used to mean "making really big photographs"
by analogy with microphotography.

Peter.
--
pirwin RemoveThis @ktb.net
 >> Stay informed about: Why do only primes have macro 

I said very close up is not feasible and not impossible please and by that I
means at least 2:1 magnification because the bellow extension will be too
long and you have difficulty in viewing the image on the ground glass. Depth
of field is shallow and you don't have that kind of aperture to stop-down
to improve. If you are a prof. you'll understand what I mean.


"Bob Salomon" <bob_salomon.TakeThisOut@mindspring.com> wrote in message
news:bob_salomon-74705B.06250014102005@news.isp.giganews.com...
> In article <dintal$6l0$1@reader01.singnet.com.sg>,
> "kctan" <kcpps.TakeThisOut@singnet.com.sg> wrote:
>
>> Therefore, very close up photography
>> is not feasible using large format camera.
>>
>
> Nonsense. It is done all the time.
>
> --
> To reply no_ HPMarketing Corp.
 >> Stay informed about: Why do only primes have macro 

In article <diokd7$77e$1@reader01.singnet.com.sg>,
"kctan" <kcpps.TakeThisOut@singnet.com.sg> wrote:

> I said very close up is not feasible and not impossible please and by that I
> means at least 2:1 magnification because the bellow extension will be too
> long and you have difficulty in viewing the image on the ground glass. Depth
> of field is shallow and you don't have that kind of aperture to stop-down
> to improve. If you are a prof. you'll understand what I mean.

Nonsense.

With a 120mm Apo Macro Sironar you can easily reach 2:1 and greater, if
you have a modular monorail camera or one with a long enough built-in
bellows. In the case of the Master Technika with a 360mm long extension
you can easily get several times 2:1 with a macro like a Luminar.

If you have a basic LF camera with a fixed 12" bed and bellows then you
would be somewhat more limited in range with a macro like the 120 but
not with a macro like the Luminar.

As for DOF you can maximize the plane of sharpness with lens movements
and subject shape with back movements. Then you can increase the DOF for
better overall sharpness with the aperture ring. This assumes, of course
that you are shooting at a bit of an angle and not head on. If shooting
head on - say a picture of the detail in the car on the back of the
$10.00 US bill the DOF would be more then adequate at the magnifications
the Luminar permits.

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