Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: francois on September 02, 2005, 01:25:04 pm

Title: Barrel Distortion Correction on DPP
Post by: francois on September 02, 2005, 01:25:04 pm: Hi,
Have you compared Photoshop CS 2 lens correction to PTlens correction?
I'm just curious :D

Francois
Title: Barrel Distortion Correction on DPP
Post by: lester_wareham on September 02, 2005, 05:24:17 pm: Quote
Hi,
Have you compared Photoshop CS 2 lens correction to PTlens correction?
I'm just curious

Francois
No I don't have PTLens, I would think they would be more or less the same, if you do this you must interpolate the pixels.

I put the results up on Lens Distortion Correction and Image Detail (http://www.zen20934.zen.co.uk/photography/distort/Lens_Distortion.htm) if your interested.
Title: Barrel Distortion Correction on DPP
Post by: lester_wareham on September 03, 2005, 06:20:32 am: Quote
The results are interesting, thanks for posting them. Now, in real world I don't know if the degradation would be apparent. Sharpening and other operations could lessen the perceived effect of lens corrections.
Yes I think you are right. I have updated the page with the effect of sharpening and a real world example that was sharpened before correction but not after.

The real world example shows almost no loss but then it was only a hand held shot.

I guess this makes me a little less worried about this problem.

PS I have also uploaded one of the test patterns so you can try this on PTLens if you want.
Title: Barrel Distortion Correction on DPP
Post by: lester_wareham on September 02, 2005, 10:03:26 am: I just did some quick tests on this and I was quite amazed to see how the PS CS2 lens correcton filter destroys fine detail all over the image not just at the corners or edge, even with quite small amounts of correction.

My tests were with artificial test paterns, but do others notice problems like this with real life targets?

PS I just noticed the title says DPP - it should say PS CS2!
Title: Barrel Distortion Correction on DPP
Post by: francois on September 02, 2005, 01:26:43 pm: Hi,
Have you compared Photoshop CS 2 lens correction to PTlens correction?
I'm just curious

Francois
Title: Barrel Distortion Correction on DPP
Post by: francois on September 03, 2005, 02:46:27 am: Quote
No I don't have PTLens, I would think they would be more or less the same, if you do this you must interpolate the pixels.

I would think so too as there's no magic involved in lens correction math!
The results are interesting, thanks for posting them. Now, in real world I don't know if the degradation would be apparent. Sharpening and other operations could lessen the perceived effect of lens corrections.

Francois