How to shape the histogram like AutoLevels does?

[Autark]

It seems that AutoLevels is generally frowned upon, so I'm trying to find an alternative. I had heard that AutoContrast is the thing to use, but I can't seem to get the same results: while AutoLevels shapes the entire histogram to cover the entire range, AutoContrast only moves the curve. How am I to produce a histogram similar to the one produced by AutoLevels?

See the attached screenshots with histograms.

[afx]

Hmm, looks like they are applied at different pipeline stages.
Autolevels rather early, Autocontrast probably together with Curves.
The image adjustment seems to be quite similar though.
What happens when you switch the Histogram from Before to After?

cheers
afx

[claudermilk]

You see the little triangles at the bottom corners of the curves? Grab those & drag to where you want to clip the histogram. Autolevels is way too strong in ASP vs Bibble5, so I've stopped using them & drag my endpoints manually now.

[DocBrown]

Auto Levels isn't frowned upon so much as it gives you what a photo "should" look like, which is only bad if you are trying to make more than just a snapshot. As an example, apply auto levels to a night or sunset shop and apply auto levels. Yech! It won't be a low light shot any more. Apply auto levels to shots taken at your last family picnic. Chances are they will see some improvement. If you are trying to replicate settings created by a tool like Auto Levels, Perfectly Clear, or some of the PhotoShop plugs that do "auto" type adjustments, then just use those tools. Its far too much work to copy something that already works just fine by itself. Not to mention auto levels doesn't apply the same curve changes to every shot. It analyzes the light in the shot and adjusts accordingly, based on what a "perfect exposure" is calculated to be. In other words, there is not one set of settings that you can use for every shot.

Sometimes using Auto Levels or Perfectly clear can provide you with a great photo, sometimes it can be the basis as a staring point for further processing, and sometimes it'll just give you crap. Experiment. That's the best way to learn when to use it and when to make your own decisions. There are lots of good tutorials on using the curves tool, just search on curves tutorial in Google.

[Autark]

The image adjustment seems to be quite similar though.

AutoLevels does a better job than AutoContrast, it's these screenshots that are too small to show the difference.

What happens when you switch the Histogram from Before to After?

[afx]

Whether AL or AC does a better job is debatable. AL happens earlier in the pipeline, AC is a convenience function for the curves tool.
So it all depends on what is happening in-between in the pipeline.

cheers
afx

[Autark]

Whether AL or AC does a better job is debatable.
afx

Sorry, I should have made clear that I was referring to this particular image.

[Autark]

[...]
Sometimes using Auto Levels or Perfectly clear can provide you with a great photo, sometimes it can be the basis as a staring point for further processing, and sometimes it'll just give you crap.

Sometimes I have found a good starting point using these tools, and then I find that straightening or cropping changes the contrast or having some other unforeseen effect. What I'm looking for is some way to "freeze" the effect of AutoLevels and continue from that.

[afx]

What I'm looking for is some way to "freeze" the effect of AutoLevels and continue from that.

That's called autocontrast

cheers
afx

[DocBrown]

[...]
Sometimes using Auto Levels or Perfectly clear can provide you with a great photo, sometimes it can be the basis as a staring point for further processing, and sometimes it'll just give you crap.

Sometimes I have found a good starting point using these tools, and then I find that straightening or cropping changes the contrast or having some other unforeseen effect. What I'm looking for is some way to "freeze" the effect of AutoLevels and continue from that.

The problems with that as I mentioned in my post is that AutoLevels will be different on each photo. Its not a generic application of settings that can be captured and reapplied to any photo.