Ansel - Image Zoning

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A plug-in for the camera RAW image processing program Bibble.
Author: Sean Puckett (

Bibble 5 note: This is a Bibble 4 plug-in. It does not work with Bibble 5.

What does Ansel do?

Ansel is an advanced plug-in for altering the histogram of your image according to the theory of light zones. It comprises three different tools which, in sequence, give you almost complete control of lighting in your image.

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If you purchase this plug-in, you do so knowing it is not compatible with Bibble 5. I do not provide installation support for Bibble 4 plug-ins, and in purchasing them you do so at your own risk. Further, I do not guarantee that any Bibble 4 plug-in will be available for Bibble 5.

Sample Output

Rudolph's Red Nose

High ISO, lots of noise. Most of the background is buried in the noise floor but there was still some detail I pulled out of the little girl's coat. I also increased the contrast on her face a little, and pulled down the highlights to make the bulbs a little hazy and add a little magic.

Ansel Sample 1 Original Info

Ansel Sample 1 Output Info

Dawn by Monitor Light

Very underexposed natural room light shot. Still, there's plenty of colour and contrast down in the blacks. Most of the magic here was just using the Midtone slider. A little bit of extra Zone 9-10 presence to add some flare to the highlights and it's pretty good.

Ansel Sample 2 Original Info

Ansel Sample 2 Output Info

And Then, the Ice Giant Sneezed

Side by side they look pretty similar, but the output is far superior as far as tonality in the blacks and detail near zones 7-8 in the ice blobs (see one of the UI screenshots for how I addressed this image).

Ansel Sample 3 Original Info

Ansel Sample 3 Output Info

Do you have a great success with Ansel you'd like to share? Please contact me at to see about getting your before/after image (and a link back to your gallery) in this space!

User Interface (two of them)

Ansel Tabbed UI Info

Ansel Zones UI Info

There are two versions of the Ansel UI. Both of them do the same thing, but approach it in a different way. When you're first starting out, you'll probably want to use "Ansel-Zones" which contains nine individual sliders; one for each zone from black to white. As you become more familiar with Ansel, you'll almost certainly want to switch to "Ansel-Tabs" in which these nine simple sliders are switched for six full-featured multizone "adjusters." (If you're at all familiar with the audio world, then you can think of the Ansel-Zones UI as a nine band graphic equalizer, whereas Ansel-Tabs is a six channel parametric equalizer.)

You can use either the Ansel-Tabs UI or the Ansel-Zones UI -- or both. The Exposure and Film Curve sections are duplicated, but the zone adjustment tools are seperate. In this way you can choose which UI to use for each image, and not worry about those settings being disturbed when you choose the other UI for a different image.

Whichever UI you choose, Ansel has some common elements -- the Exposure, Film Curve and Modifier groups. We'll talk about those first. But first... the usual Enable/Reset/About explanation...

Enable Checkbox

The enable checkbox controls whether Ansel's settings affect the image.

Neg. Checkbox (new in 1.1)

Negates the image for easier inspection of shadow and near-black values.

Reset Button

Clicking the reset button forces all of Ansel's sliders to reasonable defaults, and disables the plug-in.

About Button

This button shows a popup with the version number, author, and homepage of the plug-in.

Exposure Controls Group

It is best to tackle image adjustment with Ansel in steps, as earlier steps modify greater portions of the image than later steps. You'll become quite frustrated if you start adjusting zones right away and then later try to tweak the exposure -- it will throw everything off. As much as possible, then, focus on each group in sequence, getting the image as close as you can to perfect before moving on to the next step.

Linear Slider

Changes light values linearly, by stops. Similar to the built-in exposure slider but with a much larger range +/- 8 stops. Be very careful with increasing exposure with this slider as it will clip at white, and highlight recovery can't save you once that happens. Only use it when you're sure you won't clip, or you are intentionally wanting to clip. All other cases should use the Midtone Slider.

Midtone Slider

This slider is almost magical -- it changes the visual "exposure" of your image without hard clipping. It works very well for recovering shadow detail in underexposed images, and highlight detail in overexposed ones.

Film Curve Group

This group recreates the effect of a film response curve in your image. Using it to increase contrast and adjust shadows and highlights to preserve the right amount of detail can produce extremely vivid and dynamic images.

Contrast Slider

Increases/decreases the film latitude. Moving this slider to the left makes the film curve steeper and compresses highlights and shadows.

Balance Slider

Shifts the curve midpoint to favour lighter or darker tones. Best used in moderation to alter the character of the image rather than as a correction for under/overexposure (use the Midtone slider for that).

Shadows Slider

Adds more latitude to the darker half of the film curve without affecting the lighter half. Best for recovering shadow details that you can't live without.

Highlights Slider

Adds more latitude to the lighter half of the film curve. Helps recover texture in near-white.

Modifiers Group

Chan/Lum Slider

Ansel, by default, adjusts each channel individually. For the most part, this means that increasing contrast will increase saturation. I, personally, like this effect. But sometimes you want to scale that back. This slider shifts Ansel from operating per channel to operating on total luminance (which is the way Siggy works). Often, I find that if an image becomes too saturated that moving this slider just a little ways towards "Lum" helps restore a more natural look.

Mixer Slider

Allows you to control how much of the "Ansel Effect" is applied to the image. It was suggested that it is often easier to go too far with a series of adjustments so that the effect is easy to perceive, and then "back off" the final result slightly so the effect is still there but at a less perceptible level. The mixer slider allows you to do this. In the audio realm, this slider would be called the "Dry/Effect" slider. A setting of 0 is 100% Ansel (in music terms, "Effect"). A setting of -1 is the original image ("Dry"). I allow you to go beyond 100% up to 200% (+1 on the slider) just because I can.

Ansel-Zones UI - Nine Zone Sliders

The set of nine sliders is the easy approach to using Ansel. Read the section below "how zone Adjustment Works" to understand more about how these are used.

The checkbox next to each slider is a visualize switch -- turn it on to see which part of the image a slider will affect. Each of the sliders affects slightly more than one zone-width of the image, so you can use them in combination without fearing for unpleasant overlabs.

Ansel-Tabs UI - Six Adjuster Tabs

This section describes the advanced UI of Ansel accessible with the Ansel-Tabs plug-in. The set of six tabs in the centre of the plug-in is the heart of Ansel. Using them will allow you to fine-tune contrast and zone presence in your image. Each tab has the following controls:

Enable checkbox

Activates/deactivates that tab's effect on the image. Flick it off/on to see how this individual adjuster is affecting the image.

Visualize checkbox

Shows you which parts of the image are affected by the tab. Actually, this isn't quite correct. All parts of the image are affected by an adjustment in Ansel -- but the Visualizer helps you see which parts of the image are central to the effect. Use the visualizer to find the part of the image you want to change. The Visualizer stays on even when you change the adjustment amount so you can continue to see the parts of the image most affected. Don't leave it on unintentionally!

Memo text field

You can type a short reminder word here for your reference. It doesn't affect the image in any way, it's just a sticky note for your convenience. I just put a word in here like "shadows" or "water" or "skintone" or whatever I'm working on. Makes it easier to come back later and make changes.

Zone slider

Selects a zone for this tab to affect most directly. Zones stretch from black (0) to white (10). The slider actually allows you to select from -1 to 11, which gives you the power to move image data down below black or above white, in a manner of speaking.

Width slider

Chooses how many adjacent zones the tab will stretch to include. The wider a zone is, the more prononced its effect -- but the less isolated it is. Narrow zones make precision adjustments, wide ones make big changes. Use the visualizer to see just what's included in the width of the adjuster.

Presence slider

Controls contrast/presence for the selected zone. See below -- this slider works just like the sliders in the Zones UI.

How Zone Adjustment Works

Read the following sentence and think about it: "Changing a Presence slider changes how many pixels appear in the zone." What does that mean? It means if you move a zone 10 (white) slider to the right (more presence), more of your image will be moved towards white. If you move a zone 5 (grey) slider to the left (more contrast), there will be fewer "grey" pixels -- they'll be shifted either darker or lighter, increasing contrast about the greys.

The presence sliders do not work as follows: "Move the slider to the right to make values lighter." That's not what happens. When you move a presence slider to the right, you cause the entire image to be adjusted to favour light levels in that zone. Conversely, when you move a slider to the left, increasing contrast, that zone becomes unfavoured, and fewer image pixels appear there.

So, how do you use it? You have to think in terms of your image's zones -- the shadows, the midtones, the highlights. Don't think about histograms, don't think about brighter or darker. Think about "there should be more detail in the shadows" or "the midtones are hazy" or "I want those clouds to stand out more." Then, pick a tab that isn't being used, turn on the visualizer, move the Zone slider until that part of the image is highlighted, tweak the Width slider if necessary, then turn off the visualizer. Now -- click to the left or rigth of the the Presence slider. Is it better? Click again. Worse? Click back. Take it gradually. These adjusters can have dramatic effects, and if you drag them you'll make huge changes. One click at a time is the way to go.

Ansel FAQ Page

Ansel FAQ - Frequently Asked Questions about the Bibble Plug-in


  • Ansel is copyright 2007 Sean M Puckett, all rights reserved. Ansel may not be distributed except via direct download from its homepage at
  • Ansel is not endorsed or sponsored by the Ansel Adams Trust, and no relationship should be inferred.
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