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Software to correct wide angle distortion (the stretching kind).
#1
You know the distortion of corrected wide angle lenses, which makes subjects to the edge of the frame/image look fat and stretched? Some wide angle lenses show this worse than others.



I read an article about correcting it, someone using software designed particularly to de-fish fisheye lenses to correct this corrected wide angle distortion. I do not remember the site I read it on, I seem to recall it was on northlight-images.co.uk, but I can not find it there. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/blink.gif' class='bbc_emoticon' alt='Big Grin' />



Anyone have an idea of where I read that article, or how to combat that kind of distortion in software?
#2
If you don't like the rectilinear correction of wide angle lenses, you can

convert it to a different projection with panoramatools (or the plugin-set

that belongs to it ... especially the remap-plugin) ... for instance a p-sphere

is a projection, that distributed the degrees of the field of view more evenly

over the image ... but the price for this is, that straight lines are no longer

straight if they do not go through the center of the image. There is always a

penalty of some sort, whichever projection you chose.



Just my 2cts ... Rainer
#3
That reminds me of this page on DxO. Haven't tried that function though.
<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.
#4
[quote name='Rainer' timestamp='1281559159' post='1687']

If you don't like the rectilinear correction of wide angle lenses, you can

convert it to a different projection with panoramatools (or the plugin-set

that belongs to it ... especially the remap-plugin) ... for instance a p-sphere

is a projection, that distributed the degrees of the field of view more evenly

over the image ... but the price for this is, that straight lines are no longer

straight if they do not go through the center of the image. There is always a

penalty of some sort, whichever projection you chose.



Just my 2cts ... Rainer

[/quote]

Ah... thanks for the tip. That sort of does the same thing as what I was searching for.



I finally found the article, and indeed it was hidden on northlight-images.co.uk:

http://www.northlight-images.co.uk/revie...-hemi.html



He uses photoshop's lens correction plug in to add some barrel distortion, and then use the Fisheye-Hemi plug in for photoshop.

[url="http://www.imagetrendsinc.com/products/prodpage_hemi.asp"]Fisheye-Hemi plugin[/url]



[quote name='popo' timestamp='1281559444' post='1688']

That reminds me of this page on DxO. Haven't tried that function though.

[/quote]

Thanks! DxO does a more complex and thorough job, interesting.
#5
[quote name='Brightcolours' timestamp='1281558346' post='1686']

You know the distortion of corrected wide angle lenses, which makes subjects to the edge of the frame/image look fat and stretched? Some wide angle lenses show this worse than others.



I read an article about correcting it, someone using software designed particularly to de-fish fisheye lenses to correct this corrected wide angle distortion. I do not remember the site I read it on, I seem to recall it was on northlight-images.co.uk, but I can not find it there. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/blink.gif' class='bbc_emoticon' alt='Big Grin' />



Anyone have an idea of where I read that article, or how to combat that kind of distortion in software?

[/quote]



Another simliar article here:

http://www.kenrockwell.com/tech/fisheye-hemi.htm
#6
I think Capture NX2 does it automatically when you convert a raw file to Jpeg!But check it, don't trust me, I am really new at this. Kindly Vieux Loup <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='Smile' />
#7
[quote name='Vieux loup' timestamp='1286377612' post='3533']

I think Capture NX2 does it automatically when you convert a raw file to Jpeg!But check it, don't trust me, I am really new at this. Kindly Vieux Loup <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='Smile' />

[/quote]

Nikon Capture NX2, like Canon DPP and Photoshop CS5/Lightroom 3 can correct barrel distortion. However, they do not correct the stretched edges.. subjects on the edge of wide angle frames look horizontally stretched. And that is what this thread was about, how to "rescue" subjects in corrected wide angle images.
  


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