Talk:Chromatic aberration - Revision history

Erik Krause: /* Great article on LCA/TCA */

2008-07-21T20:58:57Z

‎Great article on LCA/TCA

Dedalus: /* Great article on LCA/TCA */

2008-07-16T10:54:34Z

‎Great article on LCA/TCA

Erik Krause: /* Great article on LCA/TCA */

2008-07-10T19:54:17Z

‎Great article on LCA/TCA

Dedalus: New section: Great article on LCA/TCA

2008-07-06T20:59:48Z

New section: Great article on LCA/TCA

Gmaxwell: Strange Example caused by IR?

2006-10-30T04:33:39Z

Strange Example caused by IR?

New page

==Strange Example==
In the strange example on the page are we perhaps seeing chromatic aberration of longer wavelength red (approaching near IR)? Most plants reflect a lot of longwave red (as made obvious in IR photographs of plants)... this would explain why correction for the plant would cause more problems for red elsewhere in the image. I'd only expect to see this if the error of the lens was fairly steep with respect to wavelength, but that wouldn't be shocking if the lens was designed for a sensor (film?) with less NIR response. --[[User:Gmaxwell|Gmaxwell]] 05:33, 30 October 2006 (CET)

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 I found http://www.vsg.dcu.ie/papers/prl_2007_chrom.pdf an article to measure and correct LCA/TCA chromatic aberration. Based on a fundamental model it measures CA on a test image (chess board pattern) to calibrate a lens. [[User:Dedalus|Dedalus]] 22:59, 6 July 2008 (CEST)
-:The upcoming [[hugin]] package will contain a tool to automatically determine TCA correction parameters ([[tca_correct]]) to be use with [[fulla]] to correct TCA. Unfortunately I don't know enough about it to write something... <small>--[[User:Erik Krause|Erik Krause]] 21:54, 10 July 2008 (CEST)</small>
+:The upcoming [[hugin]] package will contain a tool to automatically determine TCA correction parameters ([[tca_correct]]) to be used with [[fulla]] to correct TCA. Unfortunately I don't know enough about it to write something... <small>--[[User:Erik Krause|Erik Krause]] 21:54, 10 July 2008 (CEST)</small>
 ::As far as I know tca_correct only takes radial TCA into account, while the paper takes asymmetric distortion due to misalignment of lens elements into account as well (so called tangential distortion). [[User:Dedalus|Dedalus]] 12:54, 16 July 2008 (CEST)

← Older revision		Revision as of 10:54, 16 July 2008
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	:The upcoming [[hugin]] package will contain a tool to automatically determine TCA correction parameters ([[tca_correct]]) to be use with [[fulla]] to correct TCA. Unfortunately I don't know enough about it to write something... <small>--[[User:Erik Krause\|Erik Krause]] 21:54, 10 July 2008 (CEST)</small>		:The upcoming [[hugin]] package will contain a tool to automatically determine TCA correction parameters ([[tca_correct]]) to be use with [[fulla]] to correct TCA. Unfortunately I don't know enough about it to write something... <small>--[[User:Erik Krause\|Erik Krause]] 21:54, 10 July 2008 (CEST)</small>
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		+	::As far as I know tca_correct only takes radial TCA into account, while the paper takes asymmetric distortion due to misalignment of lens elements into account as well (so called tangential distortion). [[User:Dedalus\|Dedalus]] 12:54, 16 July 2008 (CEST)

← Older revision		Revision as of 19:54, 10 July 2008
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	I found http://www.vsg.dcu.ie/papers/prl_2007_chrom.pdf an article to measure and correct LCA/TCA chromatic aberration. Based on a fundamental model it measures CA on a test image (chess board pattern) to calibrate a lens. [[User:Dedalus\|Dedalus]] 22:59, 6 July 2008 (CEST)		I found http://www.vsg.dcu.ie/papers/prl_2007_chrom.pdf an article to measure and correct LCA/TCA chromatic aberration. Based on a fundamental model it measures CA on a test image (chess board pattern) to calibrate a lens. [[User:Dedalus\|Dedalus]] 22:59, 6 July 2008 (CEST)
		+
		+	:The upcoming [[hugin]] package will contain a tool to automatically determine TCA correction parameters ([[tca_correct]]) to be use with [[fulla]] to correct TCA. Unfortunately I don't know enough about it to write something... <small>--[[User:Erik Krause\|Erik Krause]] 21:54, 10 July 2008 (CEST)</small>

← Older revision		Revision as of 20:59, 6 July 2008
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	==Strange Example==		==Strange Example==
	In the strange example on the page are we perhaps seeing chromatic aberration of longer wavelength red (approaching near IR)? Most plants reflect a lot of longwave red (as made obvious in IR photographs of plants)... this would explain why correction for the plant would cause more problems for red elsewhere in the image. I'd only expect to see this if the error of the lens was fairly steep with respect to wavelength, but that wouldn't be shocking if the lens was designed for a sensor (film?) with less NIR response. --[[User:Gmaxwell\|Gmaxwell]] 05:33, 30 October 2006 (CET)		In the strange example on the page are we perhaps seeing chromatic aberration of longer wavelength red (approaching near IR)? Most plants reflect a lot of longwave red (as made obvious in IR photographs of plants)... this would explain why correction for the plant would cause more problems for red elsewhere in the image. I'd only expect to see this if the error of the lens was fairly steep with respect to wavelength, but that wouldn't be shocking if the lens was designed for a sensor (film?) with less NIR response. --[[User:Gmaxwell\|Gmaxwell]] 05:33, 30 October 2006 (CET)
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		+	== Great article on LCA/TCA ==
		+
		+	I found http://www.vsg.dcu.ie/papers/prl_2007_chrom.pdf an article to measure and correct LCA/TCA chromatic aberration. Based on a fundamental model it measures CA on a test image (chess board pattern) to calibrate a lens. [[User:Dedalus\|Dedalus]] 22:59, 6 July 2008 (CEST)