Blocked Shadows? What Presets Can Do to Help

We had a few rainy days and I took the chance to explore the dynamic range of my camera using Ansel Adam’s Zone System/Method and see, what PhotoLab can do to get the most of it - and how.

The following can help to extend shadow details, specially in shots of dark places, but it’s by no means the magic bullet.

Let’s have a look at this screenshot:

We see three rows of images that PhotoLab exported from an exposure test series

  • Top row: Jpeg output of images treated with the “DxO Standard” preset
  • Middle row: Jpeg output of images treated with the “No Correction” preset
  • Bottom row: Same as top row, but Colour Rendering set to Neutral/Realistic/Gamma 2.2
  • Images marked with a green dot don’t show any structure

While highlight rendering does not change (leftmost images correspond to Zone X), we can improve shadow details by 2-3 stops (using DxO Standard) and another 1-2 stops by setting Colour Rendering as mentioned above.

Using this colour rendering…
Bildschirmfoto 2021-12-05 um 12.34.00.894
…will start your images with a fairly bland appearance, but it will show you what otherwise might be buried in the shadows. Note that for prints, the usable range of contrast extends to about 7 stops, which corresponds to 2 stars and above - in the middle row of images.

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Ansel Adam’s Zone System doesn’t really work for digital positive images as it was designed for negative film, which has a much more restricted dynamic range.

Indeed printing range on “wet” prints is around 7 stops but I have found that inkjet paper can cope with 8 (at a push). However, B&W negative film has a range of 10 stops, hence the 10 zones in the Zone System - the idea being to expose a negative in such a way that, in the case of a contrasty subject, any parts of the subject outside of those 10 stops are “compressed” into the 10 stops; and, in the case of a low contrast subject, they can be “expanded” to better fill the available range.

Exposing for a B&W neg involves starting by “placing” the darkest part of the subject, for which you require to see detail, in Zone 3; measuring the brightest part of the subject to determine the total range and then calculating how many stops above Zone 3 you have left to fit the rest of the range into.

Most modern sensors have around a 12 stop range at low ISO (some more, the Nikon D850 has 14.6).

But, more importantly, instead of placing the shadow detail minimum in Zone 3, you need to take account of the fact that 12 stops of dynamic range is very unevenly split around the 18% grey level that exposure meters measure for.

In the case of an example 12 stop range sensor, you will usually find that you only have 2 stops above 18% grey before the highlights on a subject are irretrievably blown.

So, taking this into account, I have devised my own DZS (Digital Zone System), which is based on the highlight end of the available dynamic range rather than the shadow end for negative film.

In the case of a subject with high dynamic range, you start by “placing” the brightest zone around +1 to +2 stops above the 18% grey level that the exposure meter will measure.

I usually start by putting the camera in manual exposure mode and setting the exposure compensation to a positive value that suits the tonality of the brightest part of the subject: if it is pure white set it to +2, if it is off-white, set it to +1, or somewhere around that.

Then, with the metering mode set to Spot mode, I measure the brightest part of the subject on the zero marker of the meter, reframe the shot and take it.

This will give an image that is perfectly exposed for the highlights but that will appear quite dark for everything else. Which is where PhotoLab’s excellent tools come into play to recover those “lost” shadow details.

Instead of using any of the DxO supplied presets, my standard procedure is to start by applying a Spot Weighted Smart Lighting correction…

Before…

With the zones defined and the mode level set to 50…

This has now “anchored” the highlight and shadow levels on the Tone Curve, which can now be adjusted to better separate out the tonalities in the lower end…

Capture d’écran 2021-12-05 à 14.07.16

This gives us the digital equivalent of the over-exposure and under-development needed to compress tonal range with B&W negative film. All that is needed now is to adjust things like fine contrast and graduated filters/Control Lines, etc to finalise the image.


This in no way invalidates what @platypus suggest, instead, it just offers an alternative methodology that I have found very useful and fast.

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Thanks for your additional input, @Joanna.

No matter what we do, we need to take into account that sensors are much less tolerant to bright light than negative film and, as we all know, that clipped highlights are pretty much the upper limit (except for cloning stuff into burnt areas) of what can be reproduced.

Bending the tone curve can bring out shadow details as you demonstrate. Not being careful with the tone curve can introduce ill effects or can be useful for psychedelic effects…

Starting out with the best possible continuous range of displayable tones is my aim here, and I do it by using the shown colour rendering variant. I can then always increase contrast etc. to get the image I want. I prefer this way to the one of “recovering” stuff that has been messed up by default presets.

Anyway, it’s just another way to Rome…

That sentence appears wrong to me. I think maybe because Ansel Adams = black and white prints. But it makes a lot sense if I put in colour negatives into the equation,

No. Like in “never”. Long times I also thought so, but it’s the photographic paper which brings in the biggest limits. B&W film goes way higher than only Zone X. Trouble is to compress the range of film to the range of paper.

Your example shows excellently why the zone system is not working well with colour pictures. Here the detailed cloud doesn’t help against the massive dark foreground, which on the other side lacks clear blacks, erasing the blue shadow tint. Sometimes a real HDR is the better way to go, I believe.

Thank you very much to bring this up. You inspired me (finally) to try some test pictures.

e.g. for B&W → https://www.northlight-images.co.uk/a-black-and-white-test-image/
Screen Shot 12-07-21 at 10.49 PM.PNG
Keith Cooper

e.g. for colour → https://www.northlight-images.co.uk/printer-test-images/#datacolor


PDI


DataColor


combined with a simple grey step

I opened the files in PL5 with “No Correction” and applied “DxO Standard Preset (DxO Smart Lighting, Uniform, 25)” to a virtual copy. – Now it’s easy to compare them instantly.

To visualize the different RGB-values ( easier with the grey step )
I chose the pic’s VC and set comparison to “No corrections (with geometry)”,
Screen Shot 12-07-21 at 11.10 PM
set the mouse pointer over one step and toggled [Strg + D] between VC and original.

It was very interesting to see the effect on different pics (also to change the given value).
And yes, it’s much easier to start post with a not to contrasty pic.


  • note 1:
    please download the shown test images from the indicated site to work with (not the screenshots)

  • note 2:
    For printing finished files (e.g. test pictures), I use PS’ softproof and might correct there the shadows, which depends on paper and subject.

On reading it again myself, I would agree that I could have worded it better.

What I’m trying to say is that the Zone System is based on reading darkest shadows with discernible detail and that B&W film, without using the Zone System, is restricted to roughly 10 stops, which is less than most modern digital sensors.

Totally agreed that the range of paper is the final limiting factor in terms of available range.

Using the Zone system allows us to exceed Zone X, but only if we apply N+ exposure/development routines; the idea being to produce the best possible negative, in order to produce the best possible print.

Usually this means “compressing” tonal range into 10 stops on the neg if possible, in order to provide a tonal range that is more easily printable - at least using darkroom techniques. In fact, we have found that you can digitally scan more than 10 stops from a neg, but Ansel Adams didn’t have that kind of help available. The most amazing example of the flexibility of scanning was the time that we accidentally under-exposed a shot, of a waterfall in a heavily wooded valley, by 4 stops! And yet we were still able to pull a printable file from it, even though the negative appeared to be virtually clear film with a couple of light grey streaks.

In this case, that is not a blue tint you can see in the shadows, but the actual colour of the rocks.

@Joanna, of us both you have the larger and deeper experience with large format and you’re still using the zone system while I was fooling around with a “simplified” JoJu version like 20 years ago.

The key of your post was: For film there’s a limit of lowest energy you need to catch, for digital sensor that limit is clearly on the highest part of energy the sensor can digest - or not.

And it doesn’t matter if that range is 12.6 or 12.8 stops as everything photographical measurements is not “all that clear” as the digital values of whatever zero point anything per stops try to suggest, I know that. I never got a proper densitometer to measure the range, so what can I say? I was a bit under the influence of a lately re-read chapter from Bruce Barnbaum’s “Art of Photography” about “10 myths of photography”. I really like Ansel Adams’ American landscapes, but Barnbaum’s “Visual Symphony” touched me more. And he knows as well how to handle a large format as he knows about digital cameras (at least about the first generations…). So I only got confirmed what I (without measuring it exactly) already seen. Some films can take a huge range of contrast.

And about the blue rocks, I’ve been in Brittany a few times, but never for long enough to discover the wide range of colours. I believe, printed you image will look stunning. Here in the small format and on a screen it looks a bit fake at first glance. Which can be deceptive… :relaxed:

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Interesting discussion…nevertheless, I cited Adam’s Zone System as the source of a way to assess capabilities of a digital pipeline rather than as a dogma.

For all who do print, compressing the tonal range of a capture remains something to consider - and adapting Adam’s method is one possible way to proceed, even hough it might not be used literally.

Customizing is about starting with the widest possible playground, printing is about how to make do.

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This is interesting.

I assume that the difference between the presets like ‘DxO Standard’ and ‘No Correction’ is to activate or de-activate certain adjustments. And in case of activation to apply a specific value for that adjustment. And that there are no other ‘behind the scenes’ adjustments.

For the preset ‘No Correction’ none of the adjustments is active. So ‘Color Rendering’ and ‘RAW White Balance’ are de-activated. But I assume that some kind of Color rendering is applied when the RAW is exported to a TIFF or JPG.

If PL applies the same color rendering and white balance as for ‘DxO Standard’, then the only differences between these presets are:

  1. DxO Smart Lighting (25)
  2. Optical corrections: Vignetting, Chromatic Aberation, Lens Sharpness, Distortion
  3. DxO Denoising (HQ)
  4. Crop (auto)

I don’t think that 2 and 4 will have impact on the shadow details. Maybe Lens Sharpness will apply a kind of local contrast on edges.

So for the difference between the top and middle row it’s likely that DxO Smart Lighting is responsible for the significant differences.

And it’s nice to see that changing the Color Rendering from ‘Camera default rendering’ to ‘Neutral color, realistic tonality (gamma 2.2)’ adds another boost to the shadows recovery.

Did you also check the other renderings:

  1. Neutral color, factory tonality
  2. Neutral color, neutral tonality
  3. Neutral color, neutral tonality v2?

The latter is part of the preset ‘Neutral colors’ in combination with a Contrast adjustment of -20 and a Color Accentuation of (Vibrance = +10, Saturation=-10).

Yes, I did, but decided to post the results of the presets that give a wider range of tones with visible details. The “jump” is in the “Neutral…(gamma 2.2)” rendering. Switching Smart Lighting on and off can make a difference too. Check out what SL does with real images and you might find that it can improve an image or make it worse… I mostly keep SL at low values or off - because it can counteract other settings.

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Joanna, I have to say I’m very grateful to you for that method (you shared it with me a while ago). Placing the two spot zones on the highlight and the lowlight makes things a lot easier for me. Although it works better for me to allow just a little over exposure on the highlight and pull that back because it gives me more room to manoeuvre in the foreground where my work lies.

The highlight is a bit far gone in this one. I did have a lower exposure that gave me more of the highlight but the foreground was more difficult to recover without too much noise and weird colour. Now that I have Deep Prime I might effectively have another stop to work with in the foreground. What do you think? Anyway, I owe you one with your name correctly spelled. :slightly_smiling_face:

Can you post the original to the lower exposure version? Either that or send it to me in a DM if you are worried about copyright

It’s long-deleted. Next time I work with a similar bracketed set I’ll send them to you. Lets do it with your name. :slight_smile: I’ll send the RAW set (NEF). I just don’t know when I’ll get to the beach again.