Sir F. A. Rien wrote:
>>>> The focal length is not an issue - what matters is that you took the
>>>> images from the same location. You are correct about the change in image
>>>> size.
>>>>
>>>> Mike Russell - www.curvemeister.com
>
> Say WHAT ???
>
> You may know curves, but you do not know optics!
>
> Differing focal lengths will alter the visual relationship between objects

You may know optics, but you do not know the implications of "... - what
matters is that you took the images from the same location"

SCNR

> not to mention barrel and other lens distortions.
>
> Technically you can make the pan, but the eye will wonder "What's WRONG?".

no, if you follow the advice

>
> For visually good pans, you should shoot in portrait (vertical) mode, lens
> of 55mm or better, overlap of 15% and USE A TRIPOD with the cameral level!
>

Sir F. A. Rien <jaSPAMc@gbr.online.com> wrote:

> >>> The focal length is not an issue - what matters is that you took the
> >>> images from the same location. You are correct about the change in image
> >>> size.
> >>>
> >>> Mike Russell - www.curvemeister.com
>
> Say WHAT ???
>
> You may know curves, but you do not know optics!
>
> Differing focal lengths will alter the visual relationship between objects

Say WHAT?

If you shoot *from the same position*, a longer focal length simply
crops the image. There will be no difference in the visual relationship
between objects.

http://www.dpreview.com/learn/?/key=perspective


--
Johan W. Elzenga johan<<at>>johanfoto.nl
Editor / Photographer http://www.johanfoto.com

nomail@please.invalid (Johan W. Elzenga) found these unused words:

>Sir F. A. Rien <jaSPAMc@gbr.online.com> wrote:
>
>> >>> The focal length is not an issue - what matters is that you took the
>> >>> images from the same location. You are correct about the change in image
>> >>> size.
>> >>>
>> >>> Mike Russell - www.curvemeister.com
>>
>> Say WHAT ???
>>
>> You may know curves, but you do not know optics!
>>
>> Differing focal lengths will alter the visual relationship between objects
>
>Say WHAT?
>
>If you shoot *from the same position*, a longer focal length simply
>crops the image. There will be no difference in the visual relationship
>between objects.
>
Say WHAT?

Obviously you've never used a zoom lens and observed the relationship
changing.

Perhaps because it is somewhat subtle ... doesn't make it not visible and
affect images 'joined' having been shot with differing focal lengths.

In article <5m94s3pvg43ithbru4iffvulpjsrbephm2@4ax.com>, jaSPAMc@gbr.online.com says...
> nomail@please.invalid (Johan W. Elzenga) found these unused words:
>
> >Sir F. A. Rien <jaSPAMc@gbr.online.com> wrote:
> >
> >> >>> The focal length is not an issue - what matters is that you took the
> >> >>> images from the same location. You are correct about the change in image
> >> >>> size.
> >> >>>
> >> >>> Mike Russell - www.curvemeister.com
> >>
> >> Say WHAT ???
> >>
> >> You may know curves, but you do not know optics!
> >>
> >> Differing focal lengths will alter the visual relationship between objects
> >
> >Say WHAT?
> >
> >If you shoot *from the same position*, a longer focal length simply
> >crops the image. There will be no difference in the visual relationship
> >between objects.
> >
> Say WHAT?
>
> Obviously you've never used a zoom lens and observed the relationship
> changing.
>
> Perhaps because it is somewhat subtle ... doesn't make it not visible and
> affect images 'joined' having been shot with differing focal lengths.
>
Ignoring second order effects such as pin-cusion distortion (which can be corrected by panorama software) and assuming
the scene is far from the camera (relative to the physical dimensions of the lenses), Johan is correct. The relative
view you get from two lenses of differing focal length is equivalent to the relative view you get by observing a scene
through two physical masks cut into sheets of cardboard (with the longer lens equivalent to a smaller hole in the
cardboard). Objects in th escene may be occluded by the edges of the mask, but they do not mysteriously shift their
relative positions.

Mike

Sir F. A. Rien <jaSPAMc@gbr.online.com> wrote:

> >If you shoot *from the same position*, a longer focal length simply
> >crops the image. There will be no difference in the visual relationship
> >between objects.
> >
> Say WHAT?
>
> Obviously you've never used a zoom lens and observed the relationship
> changing.
>
> Perhaps because it is somewhat subtle ... doesn't make it not visible and
> affect images 'joined' having been shot with differing focal lengths.

If you make close-up to macro shots, and you use a zoomlens where the
length of the lens changes when the zoom position changes, then you may
observe this. It's because you are effectively changing lens position
slightly when zooming such a lens. If you use a lens with internal
focussing and zooming, you will not see any change, even if you make
close ups. This is totally irrelevant however, because it is very
unlikely that the OP is making close-up shots. We are talking about a
panorama, remember?

Once again, you may read this (which you 'conveniently' deleted when
quoting me): http://www.dpreview.com/learn/?/key=perspective


--
Johan W. Elzenga johan<<at>>johanfoto.nl
Editor / Photographer http://www.johanfoto.com

Mike <m.fee@iirrll..ccrrii..nnzz> found these unused words:

>In article <5m94s3pvg43ithbru4iffvulpjsrbephm2@4ax.com>, jaSPAMc@gbr.online.com says...
>> nomail@please.invalid (Johan W. Elzenga) found these unused words:
>>
>> >Sir F. A. Rien <jaSPAMc@gbr.online.com> wrote:
>> >
>> >> >>> The focal length is not an issue - what matters is that you took the
>> >> >>> images from the same location. You are correct about the change in image
>> >> >>> size.
>> >> >>>
>> >> >>> Mike Russell - www.curvemeister.com
>> >>
>> >> Say WHAT ???
>> >>
>> >> You may know curves, but you do not know optics!
>> >>
>> >> Differing focal lengths will alter the visual relationship between objects
>> >
>> >Say WHAT?
>> >
>> >If you shoot *from the same position*, a longer focal length simply
>> >crops the image. There will be no difference in the visual relationship
>> >between objects.
>> >
>> Say WHAT?
>>
>> Obviously you've never used a zoom lens and observed the relationship
>> changing.
>>
>> Perhaps because it is somewhat subtle ... doesn't make it not visible and
>> affect images 'joined' having been shot with differing focal lengths.
>>
>Ignoring second order effects such as pin-cusion distortion (which can be corrected by panorama software) and assuming
>the scene is far from the camera (relative to the physical dimensions of the lenses), Johan is correct.

Special case situations always modify the status. My objection was to your
blanket statement that "focal length is not an issue".

>The relative
>view you get from two lenses of differing focal length is equivalent to the relative view you get by observing a scene
>through two physical masks cut into sheets of cardboard (with the longer lens equivalent to a smaller hole in the
>cardboard). Objects in th escene may be occluded by the edges of the mask, but they do not mysteriously shift their
>relative positions.

I never mentioned shifting 'relative positions', my word selection was
"relationships". If you chose to infer that means 'position' or 'size', I
can't that.

Example:
Shoot a person's face full frame with a portrait lens of, say, 105mm (35mm
format). Next shoot it with a 28mm lens. The relationships of the objects
that comprise the person have changed. Small ears, big nose! (yes, I -=did=-
see your caveat of the special case of 'far enough' restriction.)

You've already covered sperical distortion.

In the net, focal length -=is=- an issue! In general, you can not ignore
'2nd order' effects IF you want good panoramas!

"which can be corrected by panorama software" ... hey! lets not then bother
about exposure and other details either! They can be corrected, but the eye
will know, if at all familiar with the scene.

nomail@please.invalid (Johan W. Elzenga) found these unused words:

>Sir F. A. Rien <jaSPAMc@gbr.online.com> wrote:
>
>> >If you shoot *from the same position*, a longer focal length simply
>> >crops the image. There will be no difference in the visual relationship
>> >between objects.
>> >
>> Say WHAT?
>>
>> Obviously you've never used a zoom lens and observed the relationship
>> changing.
>>
>> Perhaps because it is somewhat subtle ... doesn't make it not visible and
>> affect images 'joined' having been shot with differing focal lengths.
>
>If you make close-up to macro shots, and you use a zoomlens where the
>length of the lens changes when the zoom position changes, then you may
>observe this. It's because you are effectively changing lens position
>slightly when zooming such a lens. If you use a lens with internal
>focussing and zooming, you will not see any change, even if you make
>close ups. This is totally irrelevant however, because it is very
>unlikely that the OP is making close-up shots. We are talking about a
>panorama, remember?
>
>Once again, you may read this (which you 'conveniently' deleted when
>quoting me): http://www.dpreview.com/learn/?/key=perspective

Just followed -=your=- example and snipped the part I found didn't fit my
side.

Doesn't have to be 'macro' or a zoom lens (just used that to hope you'd have
observed!), the optics alter the image.

Perspective, size are but two relationships in an image - there are more,
but ... you're an 'expert'!

Sir F. A. Rien <jaSPAMc@gbr.online.com> wrote:

> Example:
> Shoot a person's face full frame with a portrait lens of, say, 105mm (35mm
> format). Next shoot it with a 28mm lens. The relationships of the objects
> that comprise the person have changed. Small ears, big nose!

You make a well-known beginners mistake. In order to shoot the face full
frame with the wide angle, you will have to change the position of the
camera: you will have get much closer to the person. THAT is what causes
the big nose and the small ears!

If you would use the wide angle *from the same distance* as the 105mm,
the nose will not become bigger and the ears will not become smaller. Of
course, the face will not be full frame in this situation, but that is
the consequence of using a wider angle *without* moving the camera.

I'm not going to quote that link for a third time, but it's obvious that
you either didn't read it or didn't understand it. Here's a few other
links. Maybe you understand one of those:

http://en.wikipedia.org/wiki/Perspec...n_(photography)
http://cornicello.blogspot.com/2007/...ective_08.html
http://jamesmskipper.tripod.com/jame...rspective.html
http://answers.yahoo.com/question/in...AAqM2oG&show=7


--
Johan W. Elzenga johan<<at>>johanfoto.nl
Editor / Photographer http://www.johanfoto.com