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View Full Version : Canon 30D, 10-22, couple of questions

Ashenden
07-13-2008, 02:47 PM
I received my N3 MKII last week and after finally realizing I can take the Adapter Screw out of the rotator base I finally got it mounted on my tripod :biggrin:

Question 1
I was reading about the Detent Rings in the forum and I have been playing with the calculator at http://www.frankvanderpol.nl/fov_pan_calc.htm. I am not sure I understand how to translate the calculations into the correct ring.

Here&#039;s the values I give it:
Focal Length: 10mm
Size Utilization: 100%
Film/CCD Length: 22.7 (I selected the 30D as the camera and it calculated this)
Film/CCD Width: 15.1
Normal Lens Overlap: 25%
Panorama FOV: 180 deg

That gives me 3.2 pictures in Portrait which sounds very low to me for 180 degrees shooting with 25% overlap.

Question 2
Page 14 of the User Guide explains how to set the upper rail. It states that I should "slide the camera on the upper rail until the NNP of the lens is centered with the upper rotator". I am not sure what NNP is (an explanation for NPP is given previously). What the best alignment for my setup?

John Houghton
07-13-2008, 11:55 PM
If you have PTGui, you can add one image in portrait orientation and it will tell you that the horizontal fov is 74 degrees.

Alternatively, you can work this out as follows:

Tangent of half the fov is 15.1/2 divided by 10 = 0.755
Half the fov is therefore 37 degrees
Total fov is 2 x 37 = 74 degrees.

For multiple shots overlapping by 25%, each extra shot adds 75% of the fov = 55 degrees.
The total for 3 shots = 75 + (3-1)x55 = 184 degrees

6 shots around would cover the full 360 degree view with (74-60)/74 x100 = 23% overlap, which should be good enough.

The web site at ww.vrwave.com will tell you how many shots are needed to make a full 360x180 panorama.

It doesn&#039;t take long to set up your panohead to avoid parallax effects. These tutorials should help:

www.johnhpanos.com/epcalib.htm (http://www.johnhpanos.com/epcalib.htm)
http://www.rosaurophotography.com/html/technical7.html

John