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Valentin Arfire
November 17th, 2008, 08:22 AM
hello friends

here is a planar from Montseny peak 1704 m
5D + Tokina 10-17
360 Pecision Adjuste + Manfrotto

http://www.europhoto.ro/valentin/BCN/Monseny/planar_Monseny_web.jpg

4000 pixel http://www.europhoto.ro/valentin/BCN/Monseny/planar_Monseny.jpg

and a spherical one from the same peak in the sunset

here (http://www.europhoto.ro/valentin/BCN/Montseny/Montseny.html)

regards,

Doug Kerr
November 17th, 2008, 04:53 PM
Hi, Valentin,
hello friends

here is a planar from Montseny peak 1704 m
5D + Tokina 10-17
360 Pecision Adjuste + Manfrotto

I am still getting used to the application of "projection" terminology to the field of panoramic photography.

What do you mean by "planar". This is for example not a rectilinear projection (I assume that the fence rails are essentially "straight" in real life.).

Thanks.

Valentin Arfire
November 17th, 2008, 05:27 PM
Dear Doug,

I found inspiration on another website and there really are people far better prepared than me to explain and debate different projections:
spherical, cylindrical and so on.
for the above example I think I've used a mercator one.

In real life of course the fence is real but the common sight is around 90 degrees - and not around 360.


http://www.panoguide.com/howto/panoramas/types.jsp

http://www.panoguide.com/howto/panoramas/whatis.jsp

Doug Kerr
November 17th, 2008, 08:26 PM
Hi, Valentin,

I found inspiration on another website and there really are people far better prepared than me to explain and debate different projections:
spherical, cylindrical and so on.
for the above example I think I've used a mercator one.

Yes, that might be. I am still trying to relate what I know about projections in other contexts to what we can do here!

Thanks.

Best regards,

Dopug

Doug Kerr
November 18th, 2008, 05:13 AM
Hi, Valentin,

Thanks for the two references on panoramic concepts.

The information there seems to suggest "planar" as a term to identify what is elsewhere in photography called a "rectilinear" projection.

That is in fact the type of projection we generally (until we get into such areas as "fisheye" lenses) hope to attain in "normal" photography. In tests of lenses, we report on the degree to which they depart from that type of projection (the "geometric distortion" part of the report).

A rectilinear projection has two important properties:

- any straight line in the three-dimensional scene will be rendered as a straight line in the image

- the array of object points lying in any plane of the scene that is parallel to the plane of the film will form in the image a "precise miniature" of that "planar array".

For example, if the photograph is of the front face of a building, with all of its features essentially lying in a plane, and that plane is parallel to the plane of the film in the camera, then the image of that building face will be a perfect miniature of the building face itself, just like an architect's "elevation" rendering of the building face. The image of the building face will be, in the sense of the term used in formal geometry, "similar" to the building face itself (all distances in the image proportional to those of the object, all angles between lines in the image identical to those of the object).

In the various sophisticated "panoramic assembly" software we have available today, which can assemble from multiple images a composite image, allowing us to simulate the results of various projections, I don't know how that projection choice (if offered) is "labeled".

Here is another handy reference on projections as applied to panoramic photography. It discusses the "rectilinear" projection.

http://www.cambridgeincolour.com/tutorials/image-projections.htm

Best regards,

Doug

Valentin Arfire
November 18th, 2008, 10:59 AM
Dear Doug and all pano-friends

I've bookmarked the link you gave for the future and its very practical calculators.

an equirectangular image is interpreted by the panorama player - say my beloved DevalVRhttp://www.devalvr.com/descargas/dps/player.zip - from something like this

http://www.europhoto.ro/valentin/BCN/Montseny/%3C..%3E/street_equirectangular.jpg

there are other very unusual images I will put here just for fun
(the program I used for these is called Pano2VR that also splits the sphere into cubefaces,converts it for quicktime or flash, makes automatic templates for mov or swf files and creates html pages with nice buttons)

mirrorball
http://www.europhoto.ro/valentin/BCN/Montseny/%3C..%3E/street_mirrorball.jpg

tunnel
http://www.europhoto.ro/valentin/BCN/Montseny/%3C..%3E/street_tunnel.jpg

and world
http://www.europhoto.ro/valentin/BCN/Montseny/%3C..%3E/street_world.jpg

I think these extreme wide images are also interesting and funny

kind regards,