DSLR custom curve: Linear vs Log scale?

[johnyu]

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. :cry:

 

[gooseberry]

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]

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.