Barrel distortion or somethijg else?

bass_junkie83

bass_junkie83

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Dave
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IMG_7434.jpg


In the above image you can see some distortion. I have adjusted the image to correct the converging verticles. I don't have the original image here to check, but i did'nt notice the distortion then, could just be me though.

So first question, is this barrel distortion or is it relating to the processing i have done. And secondly, how can i correct it?
I have a copy of photoshop 6.0 which is what i originally used to correct the verticles.

Cheers
 
Elements can correct barrel distortion, its under fliters>correct camera distortion.

Looks like barrel distortion to me, correct that first then adjust the verticals.

Alternatively if shot with a compatible Canon lens, DPP can correct for barrel distortion automatically if selected.
 
I was using a sigma 18-50 f2.8.

I don't have elements, it's just an olf full copy of photoshop from back when i used it for uni.
I thought i could sort it on DPP, but couldn't for the life of me work out how.
 
It's barrel distortion. You can correct it in Photoshop, or there are a couple of other programmes that will do it very easily, and to a higher standard if the distortion is of the tricky 'moustache' type.

Canon's DPP is the Raw processing software that came with your camera, and it has sophisticated automatic custom correction for distortion, vignetting and CA programmed for every Canon lens. With a 400D you probably don't have the newer version necessary for this, but if you can get a free upgrade from here: http://software.canon-europe.com/ This is a brilliant programme that makes even modest lenses shine like an L, but it only works with Canon lenses.

There's another programme called PTLens that does a similar thing, if not to quite such a high standard, and that has pretty much every lens covered. PTLens is $25 I think: http://epaperpress.com/ptlens/

Edit: crossed post. I see you have a Sigma, so DPP won't work. Either do it manually then, or try PTLens if you need to do this sort of thing often. Don't know if you can fool DPP into thinking you've used a Canon lens - the EF-S 17-85 has similar kind of distortion at 17mm.
 
Nah, won't work with DPP I'm afraid.

I can't remember if the older versions of PS had lens correction in, I assume they do, got 5.5 at home on an old PC but can't remember.

PTLens is a handy plugin and is cheap to boot, it does a good job on vignetting and distortion correction, but I'm less impressed on its chromatic aberration function.
 
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