Magic Lantern Forum

Using Magic Lantern => Raw Video => Topic started by: mannfilm on August 27, 2014, 08:27:38 PM

Title: Avoid using lens correction in ACR and resolve
Post by: mannfilm on August 27, 2014, 08:27:38 PM
Lens correction in ACR or resolve changes every pixel. (Its basically the transform or Distort tool.) Still photographers have been avoiding it for years. They claim it kills the perceived resolution and the quality of the image.  Can also introduce video artifacts, including moire. As a ACR function, it is not designed for video, but for stand alone photographs, so the "correction" can easily vary from frame to frame.
Title: Re: Avoid using lens correction in ACR and resolve
Post by: Walter Schulz on August 27, 2014, 08:58:12 PM
Thanks, but are there any examples showing such effects?
I'm a still photographer and I'm not avoiding lens correction that much.
Title: Re: Avoid using lens correction in ACR and resolve
Post by: DFM on August 27, 2014, 10:09:15 PM
Lens correction is a geometrical transform based entirely on fixed profile data - it is not adaptive.
Title: Re: Avoid using lens correction in ACR and resolve
Post by: jimmyD30 on August 27, 2014, 10:54:14 PM
I use lens correction for video in ACR and I can tell it's never varied from frame to frame.
Title: Re: Avoid using lens correction in ACR and resolve
Post by: Rodrigo Riedel on August 29, 2014, 06:24:32 AM
I agree, it's worked perfectly for me all the time
Title: Re: Avoid using lens correction in ACR and resolve
Post by: ChadMuffin on August 29, 2014, 04:11:41 PM
I have been using it most of the time. I haven't noticed any variations of distortion or moire in ACR. While it can be argued that lens corrections, fixing distortion that comes with a given lens, can ruin that lens look. But, you may not always want that. Trying to keep color correction, or just making sure each shot doesn't vary too much between shots can make lens corrections useful depending on how you are shooting. Same thing with vignetting.. I'm looking at you Canon 50mm f1.4.
Title: Re: Avoid using lens correction in ACR and resolve
Post by: hateom on September 21, 2014, 05:44:29 PM
Same here, I've been using it for a long time. I agree with the second argument - it can decrease the resolution, especially on a footage shot with wide angle lenses when a barrel distortion is significant.