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Author Topic: Lens Limits  (Read 10625 times)

Geo

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Lens Limits
« on: August 30, 2010, 12:47:43 PM »
I am using a Canon T2i with a 9mm Samyang lens.  I am having difficulty creating a 3D model with this lens.  Photoscan seems to align a set of photo's, but the resulting 3D model does not represent the true scene at all.

Q1) Are there any limits on the types of lenses that can be used with Photoscan?

Q2) Can Photoscan generate 3D models with the 9mm lens?  Would adding the lens calibration parameters assist the 3D model generation (I have calibration parameters from stitching full 360 panorama's)?

 
 

Dmitry Semyonov

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Re: Lens Limits
« Reply #1 on: August 30, 2010, 03:21:25 PM »
Hello, Geo,

There are no restrictions on the focal length of the used lens, as long as the following conditions are met:

1. The distortions of the lens can be well modeled using the Brown's distortion model:
http://en.wikipedia.org/wiki/Radial_distortion

2. Cameras are not observed by each other (at least the majority of them).

Manual lens calibration is usually required when focal length information is not available in the EXIF meta data. As PhotoScan assumes 50mm focal length in this case, the alignment procedure can fail or produce wrong results if the real focal length is too different.

If you can send a sample photo set for your lens to support@agisoft.ru, we could investigate the problem more thoroughly.

With best regards,
Dmitry Semyonov
AgiSoft LLC
With best regards,
Dmitry Semyonov
Agisoft