Simulating Macro by pulling lens of body

If I pull a 50mm lens off the camera body so I can focus closer how
accurately does that simulate what a 50mm macro lens would do? I focused on
a negative and I could fill a quarter of the view finder at roughly 4 inches
or so from the front of the lens which I think simulates 1:2. And I could
fill the whole viewfinder at 2 inches which I thinks simulates 1:1 using an
extension tube. Does EF work at those close ranges? Is there a maximum focal
distance?

TIA
Chris

"Chris Stolpe" wrote in
om:

If I pull a 50mm lens off the camera body so I can focus closer how
accurately does that simulate what a 50mm macro lens would do? I
focused on a negative and I could fill a quarter of the view finder at
roughly 4 inches or so from the front of the lens which I think
simulates 1:2. And I could fill the whole viewfinder at 2 inches which
I thinks simulates 1:1 using an extension tube. Does EF work at those
close ranges? Is there a maximum focal distance?


As you seem to be aware, you're doing exactly what extension tubes
do, so there's nothing wrong with it in theory. EF should work fine,
provided there's enough light.

You will lose the ability to focus at infinity, or indeed any
distance at all, given enough extension. You will also lose a bit of light,
since the lens is designed for a certain image circle and, by extending it
away from the body further, you're widening the circle and thus spreading
the light out more.

In these respects, this puts you behind a typical macro lens, which
is optimized for close work, but maintains a f2.8 maximum aperture
(usually) and the ability to focus all the way to infinity as well.
Depending on your 50mm lens and how much extension, you may not lose much,
since 50s are usually faster than macros, being f1.8 or 1.4. This wouldn't
matter a whole lot - depth of field drops to eentsy amounts so you'll
typically be shooting at f8 or much smaller anyway.

Dedicated macro lenses are designed to be ultra-sharp, and usually
beat out all others in any manufacturer's lineup. They're also optimized
for a flat subject (such as copy-stand work) and provide close to the same
sharpness from center to corner, something a standard 50 likely won't do.

So in a pinch, extension tubes (or whatever) on a standard 50mm lens
will work fine. But if you're serious about closeup work, a dedicated macro
is recommended. And following that, I'd go for a 100mm or longer macro
instead, which gives you better working distance, allowing you to shoot shy
subjects easier and also be less likely to eclipse your light source.

Good luck!


- Al.

--
To reply, insert dash in address to match domain below
Online photo gallery at www.wading-in.net

Moving the lens farther from the body is exactly what a macro lens does -
it simply has a variable extension tube built in. The AE may or may not work
well depending on the camera, the lens and the extension tubes used. Flash
exposure will be more complicated too, but once you have determined the
proper amount of flash for a given distance it will be the same for every
shot -- within reason - it is still going to be necessary to do some
bracketing as the correct exposure is not necessarily going to be the best
exposure.
If you have a 100 mm lens you can get a better working distance for flash
but will need twice as much extension.

--
http://www.chapelhillnoir.com
home of The Camera-ist's Manifesto
The Improved Links Pages are at
http://www.chapelhillnoir.com/links/mlinks00.html
A sample chapter from "Haight-Ashbury" is at
http://www.chapelhillnoir.com/writ/hait/hatitl.html

"Chris Stolpe" wrote in message
om...
If I pull a 50mm lens off the camera body so I can focus closer how
accurately does that simulate what a 50mm macro lens would do? I focused
on
a negative and I could fill a quarter of the view finder at roughly 4
inches
or so from the front of the lens which I think simulates 1:2. And I could
fill the whole viewfinder at 2 inches which I thinks simulates 1:1 using
an
extension tube. Does EF work at those close ranges? Is there a maximum
focal
distance?

TIA
Chris

A person *pretending* to be a photographer said:
A macro "as a variable extension tube built in"? WTF are you talking
about?
The front element moves further but it would be misleading to call
that a
"variable extension tube".

sigh.. Someone's lack of experience showing again...

MANY `real` macro lenses (ie the ones that aren't consumer zooms or
add-on lenses) reach macro magnification simply by moving the ENTIRE
lens outwards. Look at a good-old-fashioned standard 50mm lens on an
SLR, and the ENTIRE lens moves outward as you focus closer - if it goes
far enough outwards, it gets to macro magnification and is designated a
Macro lens. Just because *your* camera (what is it by the way, and
will we EVER see examples?) may have a `moving front element`, doesn't
mean every other camera and lens works like it. (In fact, I think you
will find on modern macro lens designs, it is MUCH more likely to be
internal elements that move, and then it is only to *avoid* that very
same lens extension.)

So .....

`WTF are YOU talking about????`

wrote in message
oups.com...
sigh.. Someone's lack of experience showing again...

MANY `real` macro lenses (ie the ones that aren't consumer zooms or
add-on lenses) reach macro magnification simply by moving the ENTIRE
lens outwards. Look at a good-old-fashioned standard 50mm lens on an
SLR, and the ENTIRE lens moves outward as you focus closer - if it goes
far enough outwards, it gets to macro magnification and is designated a
Macro lens. Just because *your* camera (what is it by the way, and
will we EVER see examples?) may have a `moving front element`, doesn't
mean every other camera and lens works like it. (In fact, I think you
will find on modern macro lens designs, it is MUCH more likely to be
internal elements that move, and then it is only to *avoid* that very
same lens extension.)

So .....

`WTF are YOU talking about????`

Wrong again boy. To focus a fixed focal length lens the front element* moves
outward which is why the front of the lens physically extends further out
(not the whole lens boy). The only exception to this is what are called
"Internal Focussing Lenses" (I just taught you a new word you can use to
impress all your little classmates). On a macro lens the front element moves
an even greater distance further out. Now shut up, you're embarrassing
yourself, again.
Sign,
me

*Front element: The first glass element or group of elements facing outward
towards the subject, mounted in a moveable barrel in the front of the lens
assembly.

PS: Were it not for your woeful lack of education I would not have replied
to your pitiful plea for attention. I own a real 100mm macro lens, chrlz
revealed that he doesn't, probably because he only has a trashy little zoom
with macro.

You've just proved your arrogance and stupidity again.

Look AGAIN at a standard 50mm lens. Does the front element move
independently of the rest of the elements? NO, not for the vast
majority of such lenses. Look at a standard 135mm portrait lens, does
the front element move relative to the rear? NO. I have SEVERAL of
these lenses. SOME lenses, as I pointed out CORRECTLY, do have moving
internal elements, BUT the whole friggin point of this thread was that
the OP was comparing MOVING HIS LENS AWAY FROM THE CAMERA BODY to an
EXTENSION TUBE.

GO ASK A REAL PHOTOGRAPHER what an extension tube does, you moron.
Tony was 100% correct. I was 100% correct.

You, as usual - 100% moron.

Go read up and learn, `me`, as you've clearly never even heard of an
extension tube (or how about bellows?), let alone used one:

http://www.shutterfreaks.com/Tips/ExtensionTube.htm

http://www.nikonians.org/html/resour...o/macro_6.html
"These extend the distance between the lens and the film plane on the
camera, increasing the magnification of the subject on that film
plane."

http://www.northrup.org/equipment/extension.htm
"Adding extension tubes reduces the minimum focusing distance."

http://www.photographic.com/phototec...72/index1.html
"..extension tubes are just light-tight spacers that fit between the
camera body and the lens. They don't contain any glass elements; they
merely increase the distance between the optical center of the lens and
the film, thus producing magnification of the image."

http://www.betterphoto.com/forms/qnaAll.asp?catID=142
"There are three standard methods for doing macros..
b. Extension tubes that go between a lens and the camera body. These
move the entire lens focusing range closer..."

If you don't know the topic - I suggest you keep your misleading
comments to yourself.

wrote in message
oups.com...
Go read up and learn, `me`, as you've clearly never even heard of an
extension tube (or how about bellows?), let alone used one:

Fool, I tried to enlighten your small mind about macro lenses. I said
nothing about extension tubes or bellows. Pay attention or STFU.
Film best,
me

wrote in message
oups.com...
Look AGAIN at a standard 50mm lens. Does the front element move
independently of the rest of the elements? NO, not for the vast
majority of such lenses. Look at a standard 135mm portrait lens, does
the front element move relative to the rear? NO. I have SEVERAL of
these lenses. SOME lenses, as I pointed out CORRECTLY, do have moving
internal elements, BUT the whole friggin point of this thread was that
the OP was comparing MOVING HIS LENS AWAY FROM THE CAMERA BODY to an
EXTENSION TUBE.

Read my first post again stupid boy. I said macro lenses do not extend away
from the body therefore they are not a variable extension tube as Tony
proposed.

GO ASK A REAL PHOTOGRAPHER what an extension tube does, you moron.
Tony was 100% correct. I was 100% correct.

I said nothing about extension tubes slow boy and you are 100% wrong again
now STFU.

Are you blind? The front element or group *is* what moves outward you
jackass.
Sign,
me

Got right up his nose with this one!!! OK, let's drive the knife in
FULLY.

Read my first post again stupid boy.
Certainly, and we will then see who is stupid, although it is perfectly
clear already. Read on, and try to comprehend. Also, why not try
QUOTING and REFUTING? (*I* know why - as soon as you have to quote
point-by-point, you realise you are highlighting your errors). So
let's go, point by excruciating point.

I said macro lenses do not extend away from the body
WRONG. Many macro lenses DO extend away from the body IN THEIR
ENTIRETY. Look it up moron, and you will see that macro lenses with
internal floating elements are a relatively new concept. You even said
this earlier:

To focus a fixed focal length lens the front element* moves outward
So you are claiming ALL fixed FL lenses have separately moving front
elements!!!!! WRONG!!! You even explained your definition with that
asterisk, to make it perfectly clear that you were WRONG again! I have
SEVEN fixed focal length lenses (for my two Pentax and two Minolta
SLRs), three of which have macro ability.

READ MY LIPS - Only ONE of them has floating front elements, FOR ALL
THE REST THE ENTIRE LENS MOVES OUTWARDS.

therefore they are not a variable extension tube as Tony proposed.
For just about ANY SLR lens/camera combination, whether that particular
lens' front element moves independently or not , you can add an
extension tube to gain close-focusing/macro ability. Those extension
tubes have no lenses, and they simply EXTEND THE LENS AWAY FROM THE
CAMERA BODY (and run a few mechanical/electrical connections). Which
is just what the OP was asking about. You seem to have lts the plot as
usual.

I said nothing about extension tubes slow boy
Really????? In YOUR VERY FIRST POST ON THIS THREAD, you said:

The front element moves further but it would be misleading to call
that a
"variable extension tube".

That certainly looks like `extension tube` to me. Maybe that's coz I'm
slow, and careful, and I can read.

and you are 100% wrong again
Audience?

Are you blind?
A bit rich coming from the boy who just said he didn't mention
extension tubes..

The front element or group *is* what moves outward you jackass.
Shall I name about a thousand examples of lenses where the entire lens
assembly moves outward?
Pentax 50/1.4
Minolta 50/1.7
Pentax 135/2.8
Minolta 100/2.8 Macro
Ricoh 135/2.8 Macro
.....
Or shall I name all the different models of extension tubes that exist
for macro use?

Lemmeguess, photographer wannabe, you have one macro lens and one zoom,
they both have floating front elements and gee whizz, you've never seen
any other lenses.....

Oh, and just for a last example to shove where the sun doesn't shine,
regarding that lame `The front element..*is* what moves outward you
jackass`... there are several macro lenses where the front element
doesn't move AT ALL - one famous one being the newer Tamron SP AF
90/2.8 macro.

So, yeah, `jackass` that front element ALWAYS moves, don't it (in your
tiny little world, anyway).....

Keep smiling, and keep digging deeper!