Help me understand highlight recovery....

[TheCipher]

Hi,

Sort of new to ASP. I haven't used the "highlight" slider much because I didn't think I ever needed it. All it does for me is INCREASES highlights. It wasn't until just now I realized it's supposed to reduce highlights!

If auto levels is used (which I always use), highlight recover increases the highlights. So you can only recover highlights with auto levels turned off, is this correct or is something going wrong? Why would I want to turn auto levels off if it works so well? Help me understand this...

The only way i can reduce highlights is by using a brush, then the highlight slider will reduce them. I realize with a brush its a new layer and levels is greyed out then, but it just adds so much work having to do this all the time.


Jim

[TheCipher]

Hmmmm nevermind, I can just use auto contrast with curves and get the same result as auto levels, but then the highlight recovery works

[hannes_hab]

One of the tips in the AfterShot Survival Guide (http://aftershotsurvivalguide.com):

As stated in the introduction, AutoLevel is better left switched off ...

AutoLevel
When you enable the AutoLevel tool, the histogram of the image
is spread to the maximum extent, so blacks become darker and
light parts become lighter. For many images that are a bit dull due
to imperfect exposure, AutoLevel is a quick way to beef them up.
However, enabling Autolevel can easily result in too many clipped
highlights, and image adjustments that change the statistics (like
crop) will change the effect of AutoLevel, making it a bit unpredict-
able. The two text fields next to the Autolevel label define the
clipping points for black and white as a percentage of the total im-
age.
Note: Using the Auto Contrast button on the Curves tool is a good alternative
to enabling the AutoLevel tool that does not continuously auto-adjust the
image

Another one:
Highlights
The Highlights slider controls highlight recovery. The nemesis of
digital imaging is blown exposures with no details. Depending on
how badly blown the highlight parts are, highlight recovery can be
used to recover some details from RAW files, but not from processed
files. However,
- - the Highlights slider can't perform magic - - !! - [better in ASP 3 but far away from being perfect - you can combine Highlight recovery with the plugins GradFilter (pro) and BEZ and also with the color tools to improve the results]
In the Exposure tool on the Tone tab, you can further adjust the highlight
recovery algorithm which sometimes helps for tricky images.