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perspective w/ 35mm lenses?

 
 
PrincePete01
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      07-16-2004
sorry if the answer to this is obvious. i've looked high and low and haven't
been able to get an answer. suppose my digital slr has a 1.5x multiplication
factor when using 35mm lenses. so a 50mm normal lens for 35mm film, will have
the coverage of a 75mm lens when used on my digital slr. but what about the
perspective? the slight compression or flattening effect that i would expect
with a 75mm lens, would i get the same effect with the 50mm lens when used on
the digital camera? what i'm really trying to get is this. a 50mm lens is
generally not a good portrait lens when used on a 35mm camera. a 75mm lens
might be more acceptable. would a 50mm lens used on a digital body (effective
75mm coverage) be an acceptable portrait lens?

peter
 
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Charles
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      07-16-2004
On 16 Jul 2004 02:16:09 GMT, http://www.velocityreviews.com/forums/(E-Mail Removed)ospam (PrincePete01)
wrote:

>sorry if the answer to this is obvious. i've looked high and low and haven't
>been able to get an answer. suppose my digital slr has a 1.5x multiplication
>factor when using 35mm lenses. so a 50mm normal lens for 35mm film, will have
>the coverage of a 75mm lens when used on my digital slr. but what about the
>perspective? the slight compression or flattening effect that i would expect
>with a 75mm lens, would i get the same effect with the 50mm lens when used on
>the digital camera? what i'm really trying to get is this. a 50mm lens is
>generally not a good portrait lens when used on a 35mm camera. a 75mm lens
>might be more acceptable. would a 50mm lens used on a digital body (effective
>75mm coverage) be an acceptable portrait lens?
>
>peter



Yes. The flattening effect you see comes from being farther from your
subject. With the digital camera you will move back to include the
same area that you would have captured with the film camera while
being closer. You can do the same thing with film, just move back
farther, then crop for just the center.


--

- Charles
-
-does not play well with others
 
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Tony Spadaro
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      07-16-2004
It depends on how you do it. If you use a fifty on a digital at the
same distance as you would on a 35 the only difference you will get is the
area of the picture. If you are too close you will dirtort features.
If you move it back until you take in the same area as you would with
an 80mm lens on a 35mm camera you will not get close up distortion. You can,
in fact do this with 35mm too. I used to shoot everything with a 50. To do a
portrait I simply moved back and cropped the picture in the darkroom.

--
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 my novel "Haight-Ashbury" is at
http://www.chapelhillnoir.com/writ/hait/hatitl.html
"PrincePete01" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> sorry if the answer to this is obvious. i've looked high and low and

haven't
> been able to get an answer. suppose my digital slr has a 1.5x

multiplication
> factor when using 35mm lenses. so a 50mm normal lens for 35mm film, will

have
> the coverage of a 75mm lens when used on my digital slr. but what about

the
> perspective? the slight compression or flattening effect that i would

expect
> with a 75mm lens, would i get the same effect with the 50mm lens when used

on
> the digital camera? what i'm really trying to get is this. a 50mm lens is
> generally not a good portrait lens when used on a 35mm camera. a 75mm lens
> might be more acceptable. would a 50mm lens used on a digital body

(effective
> 75mm coverage) be an acceptable portrait lens?
>
> peter



 
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David Dyer-Bennet
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      07-16-2004
(E-Mail Removed)ospam (PrincePete01) writes:

> sorry if the answer to this is obvious. i've looked high and low and haven't
> been able to get an answer. suppose my digital slr has a 1.5x multiplication
> factor when using 35mm lenses. so a 50mm normal lens for 35mm film, will have
> the coverage of a 75mm lens when used on my digital slr. but what about the
> perspective?


The perspective is controlled by the distance between camera and
subject. The focal length does not influence the perspective in any
way, shape, or form.

You can see this in those sequences of photos often printed on
mats displayed on camera-store counters -- a sequence of photos taken
from the same location with each of the lenses in some manufacturers
lineup. Each photo looks like it was just cropped out of the center
of the previous photo (if the ordering is wideangle to telephoto, as
it usually is).
--
David Dyer-Bennet, <(E-Mail Removed)>, <http://www.dd-b.net/dd-b/>
RKBA: <http://noguns-nomoney.com/> <http://www.dd-b.net/carry/>
Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <http://dragaera.info/>
 
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dave6431@verizon.net
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      08-01-2004
On 16 Jul 2004 02:16:09 GMT, (E-Mail Removed)ospam (PrincePete01)
wrote:
>what i'm really trying to get is this....would a 50mm lens used on a digital body (effective
>75mm coverage) be an acceptable portrait lens?
>
>peter


Actually, it will not make any deifference at all. Lens focal length
has nothing to do with perspective. In fact perspective wasn't even
invintet until railroads became popular. There is no such thing as a
telephoto/wide angle look. I just looks like there is a telephoto/
wideangle look and if you really knew how to look, it wouldn't look
like there is a telephoto/wideangle to look at in the first place.
This can be proven by always using a 7mm lens (any format) and adding
a twelve foot post to your enlarger. You do have to protect your
wideangle prints from nose gease because the proper viewing distance
is focal length times magnification. This does mean the proper viewing
distance for an 8X10inch print from a full from a 35mm camera equiped
with a 500mm lens is eighty inches. Everyone know all this and in fact
is a given on at least one news list.

Objects in the mirror
are really not closer than they apear
so always burn out
when in reverse gear.

Heh heh heh......

 
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Jack-of-the-Dust
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Posts: n/a
 
      08-01-2004
An over simplified answer. Were it so why would manufactures make so many
different lens focal lengths?
The answer is correct from a technical stand point, but like many things
practical issues invade reason.

Ed
<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On 16 Jul 2004 02:16:09 GMT, (E-Mail Removed)ospam (PrincePete01)
> wrote:
> >what i'm really trying to get is this....would a 50mm lens used on a

digital body (effective
> >75mm coverage) be an acceptable portrait lens?
> >
> >peter

>
> Actually, it will not make any deifference at all. Lens focal length
> has nothing to do with perspective. In fact perspective wasn't even
> invintet until railroads became popular. There is no such thing as a
> telephoto/wide angle look. I just looks like there is a telephoto/
> wideangle look and if you really knew how to look, it wouldn't look
> like there is a telephoto/wideangle to look at in the first place.
> This can be proven by always using a 7mm lens (any format) and adding
> a twelve foot post to your enlarger. You do have to protect your
> wideangle prints from nose gease because the proper viewing distance
> is focal length times magnification. This does mean the proper viewing
> distance for an 8X10inch print from a full from a 35mm camera equiped
> with a 500mm lens is eighty inches. Everyone know all this and in fact
> is a given on at least one news list.
>
> Objects in the mirror
> are really not closer than they apear
> so always burn out
> when in reverse gear.
>
> Heh heh heh......
>



 
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Nostrobino
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Posts: n/a
 
      08-01-2004

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On 16 Jul 2004 02:16:09 GMT, (E-Mail Removed)ospam (PrincePete01)
> wrote:
> >what i'm really trying to get is this....would a 50mm lens used on a

digital body (effective
> >75mm coverage) be an acceptable portrait lens?
> >
> >peter

>
> Actually, it will not make any deifference at all. Lens focal length
> has nothing to do with perspective.


That depends on how you use the term "perspective." In the way that most
people use it, it definitely is related to focal length.


> In fact perspective wasn't even
> invintet until railroads became popular. There is no such thing as a
> telephoto/wide angle look. I just looks like there is a telephoto/
> wideangle look


If it "just LOOKS" that way, then obviously there IS such a thing as a wide
angle or telephoto look.


> and if you really knew how to look, it wouldn't look
> like there is a telephoto/wideangle to look at in the first place.


This is the fallacy of that whole argument. People look at photos as they
are, and any different appearance "if [they] really knew how to look" is
irrelevant.

The way this argument usually goes is something like this: If you take two
photos of the same subject from the same position they have the same
perspective, whether you shoot with a wide angle, normal or telephoto lens.

Anyone who actually does this will see VERY OBVIOUS differences in
perspective. But the argument goes along these lines: Aha, but if you took
the central portion of the wide angle shot and enlarged it so that its field
of view would be exactly the same as that of the normal or tele lens, then
the perspective would also be exactly the same.

Yes, that's true, but people DON'T do that. The full shot taken with a wide
angle lens has a wide-angle perspective, and the shot taken with a telephoto
lens has a telephoto perspective. If you take a wide-angle shot and crop out
everything except what would appear in a telephoto shot, all you've done is
EMULATED the telephoto lens. The original PERSPECTIVE has been destroyed by
what you removed.


> This can be proven by always using a 7mm lens (any format) and adding
> a twelve foot post to your enlarger. You do have to protect your
> wideangle prints from nose gease because the proper viewing distance
> is focal length times magnification.


But no one CARES about "proper viewing distance." If we see a shot taken
with a very long telephoto, we do not put it at the far end of a room just
so we can look at it in the "proper perspective." That would, in fact,
defeat the whole purpose of using a long lens in the first place.

Similarly, no one puts his nose down on the print just because it was shot
with an ultra-wide lens.


> This does mean the proper viewing
> distance for an 8X10inch print from a full from a 35mm camera equiped
> with a 500mm lens is eighty inches. Everyone know all this and in fact
> is a given on at least one news list.


This sort of nonsense has been often repeated, that much is true. It's still
nonsense, no matter how often it's repeated.

If it were true and/or relevant, no one would ever bother using a 500mm or
other long tele lens. What would be the point, if the print had to be viewed
from some unnaturally and inconveniently long distance?


 
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Bart van der Wolf
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Posts: n/a
 
      08-01-2004

"Nostrobino" <(E-Mail Removed)> wrote in message
newsYcPc.3857$(E-Mail Removed) m...
>
> <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...

SNIP
> > Actually, it will not make any deifference at all. Lens focal

length
> > has nothing to do with perspective.

>
> That depends on how you use the term "perspective." In the way that

most
> people use it, it definitely is related to focal length.


It is important to understand that perspective is only(!) influenced
by distance from the (front) principal point of the lens to the
subject.
*If* most people use it as a *combination of* distance and
field-of-view, they are wrong.

Bart

 
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DSphotog
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Posts: n/a
 
      08-02-2004

"Nostrobino" <(E-Mail Removed)> wrote in message
newsYcPc.3857$(E-Mail Removed) m...
>
> <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > On 16 Jul 2004 02:16:09 GMT, (E-Mail Removed)ospam (PrincePete01)
> > wrote:
> > >what i'm really trying to get is this....would a 50mm lens used on a

> digital body (effective
> > >75mm coverage) be an acceptable portrait lens?
> > >
> > >peter

> >
> > Actually, it will not make any deifference at all. Lens focal length
> > has nothing to do with perspective.

>
> That depends on how you use the term "perspective." In the way that most
> people use it, it definitely is related to focal length.
>
>
> > In fact perspective wasn't even
> > invintet until railroads became popular. There is no such thing as a
> > telephoto/wide angle look. I just looks like there is a telephoto/
> > wideangle look

>
> If it "just LOOKS" that way, then obviously there IS such a thing as a

wide
> angle or telephoto look.
>
>
> > and if you really knew how to look, it wouldn't look
> > like there is a telephoto/wideangle to look at in the first place.

>
> This is the fallacy of that whole argument. People look at photos as they
> are, and any different appearance "if [they] really knew how to look" is
> irrelevant.
>
> The way this argument usually goes is something like this: If you take two
> photos of the same subject from the same position they have the same
> perspective, whether you shoot with a wide angle, normal or telephoto

lens.
>
> Anyone who actually does this will see VERY OBVIOUS differences in
> perspective. But the argument goes along these lines: Aha, but if you took
> the central portion of the wide angle shot and enlarged it so that its

field
> of view would be exactly the same as that of the normal or tele lens, then
> the perspective would also be exactly the same.
>
> Yes, that's true, but people DON'T do that. The full shot taken with a

wide
> angle lens has a wide-angle perspective, and the shot taken with a

telephoto
> lens has a telephoto perspective. If you take a wide-angle shot and crop

out
> everything except what would appear in a telephoto shot, all you've done

is
> EMULATED the telephoto lens. The original PERSPECTIVE has been destroyed

by
> what you removed.
>
>
> > This can be proven by always using a 7mm lens (any format) and adding
> > a twelve foot post to your enlarger. You do have to protect your
> > wideangle prints from nose gease because the proper viewing distance
> > is focal length times magnification.

>
> But no one CARES about "proper viewing distance." If we see a shot taken
> with a very long telephoto, we do not put it at the far end of a room just
> so we can look at it in the "proper perspective." That would, in fact,
> defeat the whole purpose of using a long lens in the first place.
>
> Similarly, no one puts his nose down on the print just because it was shot
> with an ultra-wide lens.
>
>
> > This does mean the proper viewing
> > distance for an 8X10inch print from a full from a 35mm camera equiped
> > with a 500mm lens is eighty inches. Everyone know all this and in fact
> > is a given on at least one news list.

>
> This sort of nonsense has been often repeated, that much is true. It's

still
> nonsense, no matter how often it's repeated.
>
> If it were true and/or relevant, no one would ever bother using a 500mm or
> other long tele lens. What would be the point, if the print had to be

viewed
> from some unnaturally and inconveniently long distance?
>

READ AND LEARN PLEASE:

perspective, (per-spktv) in art, any method employed to represent
three-dimensional space on a flat or relief surface. Linear perspective, in
the modern sense, was probably first formulated in 15th-cent. Florence by
the architects Brunelleschi and Alberti. It depends on a system in which
objects are foreshortened as they recede into the distance, with lines
converging to a vanishing point that corresponds to the spectator's
viewpoint. Used by such Renaissance artists as Donatello, Masaccio, and
Piero della Francesca, the technique of linear perspective exerted an
enormous influence on subsequent Western art. Its use declined in the 20th
cent. Aerial (atmospheric) perspective, which is based on the perception
that contrasts of color and shade appear greater in near objects than in
far, and that warm colors appear to advance and cool colors to recede, was
developed primarily by Leonardo da Vinci, in the West, and was often used in
East Asian art, where zones of mist were often used to separate near and far
space.


 
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David Littlewood
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Posts: n/a
 
      08-02-2004
In article <xYcPc.3857$(E-Mail Removed)> , Nostrobino
<(E-Mail Removed)> writes
>
><(E-Mail Removed)> wrote in message
>news:(E-Mail Removed).. .
>> On 16 Jul 2004 02:16:09 GMT, (E-Mail Removed)ospam (PrincePete01)
>> wrote:
>> >what i'm really trying to get is this....would a 50mm lens used on a

>digital body (effective
>> >75mm coverage) be an acceptable portrait lens?
>> >
>> >peter

>>
>> Actually, it will not make any deifference at all. Lens focal length
>> has nothing to do with perspective.

>
>That depends on how you use the term "perspective." In the way that most
>people use it, it definitely is related to focal length.
>

That's not the way most people use it. It means (in this context) the
apparent size of various parts of the scene relative to one another.
Objects further from the camera are reproduced at smaller magnification
than those closer to it, but the percentage change varies as the camera
is moved towards or away from the objects.

Perspective is determined by position only. Focal length determines
field of view.

BTW, there is another apparently different use of "perspective" in
referring to the convergence of parallel lines which are at an angle to
the lens axis. However, on closer analysis, this is in fact exactly the
same phenomenon, i.e. the lines appear to get closer together as they
get further away from the photographer because the magnification is
lower.

>
>> In fact perspective wasn't even
>> invintet until railroads became popular. There is no such thing as a
>> telephoto/wide angle look. I just looks like there is a telephoto/
>> wideangle look


Perspective was well known to artists (well, some artists at any rate)
long before railways were built.
>
>If it "just LOOKS" that way, then obviously there IS such a thing as a wide
>angle or telephoto look.
>

The only reason there is a "telephoto look" is because the pictures are
taken from a great distance.

>
>> and if you really knew how to look, it wouldn't look
>> like there is a telephoto/wideangle to look at in the first place.

>
>This is the fallacy of that whole argument. People look at photos as they
>are, and any different appearance "if [they] really knew how to look" is
>irrelevant.
>
>The way this argument usually goes is something like this: If you take two
>photos of the same subject from the same position they have the same
>perspective, whether you shoot with a wide angle, normal or telephoto lens.
>
>Anyone who actually does this will see VERY OBVIOUS differences in
>perspective.


No they won't. They will simply see differences in the field of view,
and probably at different magnifications (and probably some differences
in grain or pixellation). Otherwise the two will be identical. The fact
that you think differently suggests that you can never have tried it.

> But the argument goes along these lines: Aha, but if you took
>the central portion of the wide angle shot and enlarged it so that its field
>of view would be exactly the same as that of the normal or tele lens, then
>the perspective would also be exactly the same.
>
>Yes, that's true, but people DON'T do that. The full shot taken with a wide
>angle lens has a wide-angle perspective, and the shot taken with a telephoto
>lens has a telephoto perspective. If you take a wide-angle shot and crop out
>everything except what would appear in a telephoto shot, all you've done is
>EMULATED the telephoto lens. The original PERSPECTIVE has been destroyed by
>what you removed.
>

No it hasn't. The field of view has been changed; the perspective
remains exactly the same.
>
>> This can be proven by always using a 7mm lens (any format) and adding
>> a twelve foot post to your enlarger. You do have to protect your
>> wideangle prints from nose gease because the proper viewing distance
>> is focal length times magnification.

>
>But no one CARES about "proper viewing distance." If we see a shot taken
>with a very long telephoto, we do not put it at the far end of a room just
>so we can look at it in the "proper perspective." That would, in fact,
>defeat the whole purpose of using a long lens in the first place.
>
>Similarly, no one puts his nose down on the print just because it was shot
>with an ultra-wide lens.
>

The only point of defining a print viewing distance is that it aims to
put you in the same relative position as that in which the photograph
was taken. I agree it's a pretty pointless exercise though, as mostly
one wants to have the perspective effect created by the original taking
position.
>
>> This does mean the proper viewing
>> distance for an 8X10inch print from a full from a 35mm camera equiped
>> with a 500mm lens is eighty inches. Everyone know all this and in fact
>> is a given on at least one news list.

>
>This sort of nonsense has been often repeated, that much is true. It's still
>nonsense, no matter how often it's repeated.


The reason the contrary view has "been often repeated" is that it is
true. Most of what you say is totally incorrect; I suggest you try
looking in some reputable textbooks.
>
>If it were true and/or relevant, no one would ever bother using a 500mm or
>other long tele lens. What would be the point, if the print had to be viewed
>from some unnaturally and inconveniently long distance?
>

One uses a long lens to get a bigger magnification without having to use
excessive enlargement post-taking; this would result in very pronounced
grain or pixellation, and much lower resolution.
--
David Littlewood
 
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