DSLR custom curve: Linear vs Log scale?

johnyu · 12th August 2004

Fotogenetic's website says: "the custom tone curves are applied in the camera on a logarithmic scale while the same curves are applied to the preview image in the Edit Camera Curves dialog box, Nikon Capture (NC), and Photoshop (PS) on a linear scale."

Is that true?!

I originally thought the in-camera custom curve was same as Photoshop's Curve and I can achieve the same effect by plotting the same curve in PS in post-processing.

If this linear vs log scale thing is true, how significant is it in practice? (i.e. Is the quality of the image substantially better or fine-tuning far easier when manipulating the curve in log scale?)

p.s. Too many new knowledge to be mastered when moving from film to DSLR.

gooseberry · 12th August 2004

I've only ever seen this logarithmic vs linear scaling mentioned by fotogenetic - don't recall reading anybody else say this. Interested to find out as well.

breakaway · 12th August 2004

it may be very significant. from what i know, the D70 uses compressed NEFs or JPEG. both of which are compressed formats and that the curve is applied before compression.

12th August 2004	#1
johnyu Member Join Date: Nov 2003 Location: Melbourne, Australia Posts: 316	DSLR custom curve: Linear vs Log scale? Fotogenetic's website says: "the custom tone curves are applied in the camera on a logarithmic scale while the same curves are applied to the preview image in the Edit Camera Curves dialog box, Nikon Capture (NC), and Photoshop (PS) on a linear scale." Is that true?! I originally thought the in-camera custom curve was same as Photoshop's Curve and I can achieve the same effect by plotting the same curve in PS in post-processing. If this linear vs log scale thing is true, how significant is it in practice? (i.e. Is the quality of the image substantially better or fine-tuning far easier when manipulating the curve in log scale?) p.s. Too many new knowledge to be mastered when moving from film to DSLR.

12th August 2004	#2
gooseberry Senior Member Join Date: Mar 2004 Location: Central West Posts: 1,913	I've only ever seen this logarithmic vs linear scaling mentioned by fotogenetic - don't recall reading anybody else say this. Interested to find out as well.

12th August 2004	#3
breakaway Member Join Date: Jul 2004 Location: Singapore Posts: 1,121	it may be very significant. from what i know, the D70 uses compressed NEFs or JPEG. both of which are compressed formats and that the curve is applied before compression.