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le Nordiste
01-06-2015, 9:57pm
Hi all,

I'm interested in Panorama, but i need some explanation.
How to find the entrance pupil of a lens ?
What are the definitions and/or differences between LPP and NPP ?

ricktas
01-06-2015, 10:19pm
There is a great article of finding the parallax points here: http://www.johnhpanos.com/epcalib.htm

However, for general photography, using a decent tripod, setting the camera to manual, not using a polariser, and you will get great results.

Using a tripod means that as you pan left or right for each frame, you are not moving back or forth very much at all. Setting the camera to manual means that you shoot all frames using the same settings (inlcuding focus), so that the exposure is the same on each frame. Not using a polariser is because a polariser works related to the position of the sun, so as you pan around for each frame, the angle of the lens, and thus the polariser, to the sun, changes, and the polariser effect changes. If you use a polariser, some areas of your panoramic image will show increased contrast etc compared to others caused by the polariser.

Some of the best panoramic photos are done with a tripod and without the person even knowing what/how parallax works.

ricktas
02-06-2015, 6:47am
I will add also that parallax is caused when we look at things cause our eyes are spaced apart. This spacing allows us to determine distance and depth. A camera lens (unless 3D) does not have two lenses side by side, so parallax is of much lesser concern. Most people can get away with using a standard tripod to get good images for stitching into a panoramic. If you really want the best, seek out a specialised panoramic head for your tripod, which works by using the sensor plane when panning the camera between shots to ensure the best possible images for stitching.

Parallax is a very minor part of getting the result you want, cause parallax is caused by two lenses set apart (like eyes), or one lens moved left or right between shots. So if you hand held your camera and took a shot, then moved 15cm to the right, and took the next shot, you create parallax issues. If you use a tripod with a panoramic head, then you alleviate parallax issues, and you do not need to know where the entrance pupil is, or what NPP or LPP even are.

http://www.ebay.com.au/bhp/panoramic-head

ameerat42
02-06-2015, 9:00am
Messieur Google has a pretty straightforward explanation on this page. (http://en.wikipedia.org/wiki/Entrance_pupil)

I do not know what LPP and NPP refer to in this context. Any long versions?

Am.

Grant S
02-06-2015, 9:34am
No Parallax Point and Least Parallax Point.

Good explanation of how to's for pano shooting. http://michel.thoby.free.fr/Fisheye_history_short/Beyond-the-pupil.html http://www.johnhpanos.com/epcalib.htm

As Rick said some of the best pano's are done without worrying about NPP or LPP. I've never bothered with any of the panos I've taken as I can use PP to fix most of the issues that with relative ease. It's much easier to use masking and blending techniques than to muck about with working out the rotation math required to set up NPP or LPP.