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Old August 6th, 2015, 03:05 AM
Asher Kelman Asher Kelman is offline
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Join Date: Apr 2006
Posts: 34,914

Originally Posted by Doug Kerr View Post
Hi, Asher,

I'm not sure I understand the part I have highlighted in red. Do you mean that whether I have the regular DNG file or the lossy-compressed DNG file loaded, I apply a consistent correction layer?

I don't know how to move correction layers from one file to another.

Interesting approach. Thanks for suggesting it.

Best regards,


Hi Doug,

Add the correction layer to the file base layer with one version of the original file and then stage that layer to the image from the other, differently compressed file.

The object of the harsh testing is to discover whether or not the file still maintains great edges and gradations. Or perhaps the colors become posterized with sections of different hue, no longer gradually changing scrim one hue to another and instead jumping from A to B with obvious differences as in a comic book.

Of course one could use Imatest or some other program.

This is essentially the same question that jpg afficionados challenge RAW devotees with!

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