Improving the tonality of images is one of the most difficult tasks. Especially the shows are either to flat or even more often to dark. There are quite a few tools on the market that address this issue. The most well known is "Shadow Highlight" in Photoshop CS. In our opinion, "Shadow Highlight" has two major shortcomings::

• It can produce halos
• With its many sliders the use is not really easy

Here we think the Shadow Illuminator plugin offers a great alternative.

This version of Shadow Illuminator works in 8 bit mode only.

Shadow Illuminator

Here is a statement from the creators of Shadow Illuminator:

"Generally, we are looking to eliminate influence of harsh illumination. It is done by estimating the illumination field from the original image and then rerendering the image as if it was illuminated with the field that is uniform or at least less varied. In this sense, the algorithm is recovering the reflectance of the surfaces, i.e., their appearance irrespective of illumination conditions."

The use is as easy as it can get. The idea is to provide fill light for the areas that are in the shadow (some not so trivial math is required here which also takes its time). The small preview is not really helpful as small sized pictures look darker than the full sized original. Fortunately this is no big deal as we mostly use Shadow Illuminator with the default settings in a new layer and tone down the right effect using the layer opacity (a good way to learn about layers is through our e-book DOP2000)

Note: Shadow Illuminator also works in PS Elements 3.0

Here is a sample session where we will learn about the use and challenges:

THis picture at ISO 400 in Heidelberg. The deep shadow in the arch is to dark. Here is what the default processing would deliver:

We would say that this is to much brightening the shadow parts and we stepped back to a 57% opacity of our new layer:

Now it looks more natural.

The noise is in the shadows

If opening up the shadows had no side effects we would have the ideal camera with unlimited dynamic range. But the reality is that all the worst noise shows up in the shadows (remember that the Canon 20D has some of the lowest noise of all DSLRs).

Here is the noise visualized by using Shadow Illuminator at its max settings (never use this for real images but noise can be seen very easily that way):

Noise of the original image at 100% magnification (processed with ACR 2.3)

Noise slightly reduced using the Helicon plugin at 100% magnification

So be careful not to brighten the shadows to much and use a top class noise reduction application like Noise Ninja, Neat Image or Helicon. All the major raw converters are not really good enough in reducing stronger noise.

We find that Shadow Illuminator gets us a lot easier to the results we want than any other shadow tool we have seen so far.

Here is an other example:

Before

After

Best you get a demo version and play with it. We hope that the developers make the demo watermark a bit less aggressive so that you can better evaluate the effect.

Noise show up!

There is a nice side effect of Shadow Illuminator. If used at max levels you can easily show the noise in images for analytical purposes. We plan to use Shadow Illuminator for our future noise tests.

1Ds file (ISO 160) opened up in Shadow/Highlight

Here is a crop of the original file and you can see the noise at high magnifications:

100% magnification

Using Shadow Illuminator at max settings makes the noise analysis much easier to even see at 100% magnification.

THe brightened shadows visualize all the noise

If you want to be able to open up later some shadows in you images it is wise to stay at low ISO levels as even then the shadows will have more noise than you might expect.

Conclusion

At a short period of time Shadow Illuminator has become an integral part of our workflow.

As mentioned above you can get a demo version here.

Highly Recommended