Dynamic Range and keeping colours real.

The HDR method has become notorious for crunchy texture and oversaturated colour. However it doesn't need to be like that.

When I took the test photos for yesterday’s post, I also took a couple of bracketed sets with both my Pentax and Olympus cameras and the RAW format version were processed in the same default manner in Aurora HDR 2019. This new version of the software analyses each photo in the bracketed set before they are combined into a HDR extended dynamic range and bit depth format. Syklum, the developers of Aurora, call this the Quantum HDR Engine which in part uses AI technology to find the scene style and key objects and then adjust tonal balance and colour to ensure detail in the highlights and also details in the shadows. This seems to produce a very natural tone mapped image. This can also do a nice job off just one RAW image providing it is reasonably exposed. My experience (less than 2 months so far) has been you can save the image at this time and be happy with both the tonal balance and colour rendering looking very natural

On the Aurora screen you then see “Filters” (collection of related sliders that can adjust key aspects of the image) om the right hand side and “Looks” (aka presets, which are specific setting of the filters). The Looks tiles along the bottom of the screen will let you experiment with different approaches to the tone mapping and possibly lead you into the those oversaturated, crunchy HDR looks, so I’ll avoid then for now. At this stage I was happy with the tonal balance but felt to colours could be stronger (looking at the colour wheel). This is an important step, rather than use the Saturation slider in the color filter (which increases the saturation of every pixel by the same amount) I used the Vibrance slider slightly (which leaves the fully saturated colours alone and only lift the saturation of lesser colourful pixels). I also increased the Color Contrast, this slider adjust the relative contrast between colours in a similar way to the normal contrast slider works with tone (luminance). It is my experience so far that small adjustment of this slider to expand colour contrast can have a big impact on how natural the resulting colour balance appears, In other words used Vibrance and Colour Contrast lightly but keep you hands off the saturations slider.

The images above compare the resulting HDR image for my Pentax K20 (one the left) and Olympus OMD EM10iii. Like the straight out of camera jpegs the Pentax HDR image is a little underexposed compared with the Olumpus but the colours are still natural but a little richer than yesterday’s Jpegs.

HSL Luminously and Tint (Tone) & Shade.

The ability to adjust a specific hue is great and the HSL slider also gives you the ability to adjust Saturation and Luminosity but when they are used together there are some complications.

To understand this better we should first look at the way artist use and name their their colour mixes. When you add White to a colour it is called a TINT and stays in the same hue (family) but it looks paler and lighter. Paler and Lighter means the saturation of the colour is lower and the luminosity (brightness) is higher. When you add Black to a colour the result is called a SHADE and the reverse happens. The colour gets duller and darker, which is again lower saturation and also its luminosity is lower.

Artist also often use the term TONE when they mix in a Neutral Grey. This should not be confused with Tonal Values meaning when talking about relative exposure (particularly in Black & White images). In Photography the alteration of the RGB colours are only lightened (adding luminance or sometimes reducing saturation) or darkened (either reducing Luminance and saturation) so the best way is just to think in terms of Tint or Shade.Many artist never add black when painting (and I’m one of those) because even a tiny amount or black pigment “kills” the colour mix. So they may use a dark neutral (like Payne’s Grey) or better still mix their own dark neutrals with complimentary colours.

To get a feel for how much colour and colour judgment is actually related to luminosity (through tints and shades) a great experiment is to take saturation down fully (-100 in Lightroom so you essentially have a black and white image, but there are many other ways to get black and white but not for this exercise) next adjust the tonal values in the normal manner you undertake. This could be contrast & brightness, or separate shadows and highlight sliders etc. Finally restore the saturation back to its original setting (in Lightroom set it back to zero).

You probably will be surprised, your colours are likely to be richer and more balanced! Try it yourself,

PhotoFriday :: Saturation

Saturation but getting wet as well as colour

For PhotoFriday‘s topic Saturation

Where did the colours go?

onder where the colour has gone? You remember stronger or richer colours and probably the subject was better lit. Some of the many issues that contributes to this disappointment, are exposure (colour get paler and washed out when overexposed or is in very strong light), the light comes from a variety of sources (AWB Automatic White Balance might not be appropriate) strong contrast (which can greatly influence the saturation) harsh light desaturates colour (so many just take photographs in the golden hours after sunrise and before sunset) or the colours in the scene just bring each other down (contrasting/conflicting colours). At the simplest level the human eye can process a greater dynamic range of light than a camera but there is also a lot of psychology associated with colour perception. 

After reading a series of articles about colour harmony by Soraya French in the artist magazine. I realised something very significant. Most artist understand colour as a relative concept. Whereas most of the photographic purists seems to be stuck in a very detail absolute colour calibration obsession. However how we see colour is anything but well calibrated and consistent. 

The outcome is a deep yearning in many photographers for "snappy" colours, because what they have captured doesn't really match what they thought the saw. The issues are partly the materials and equipment but a lot is in the eye of the beholder. If an artist wants a red to look redder he or she will surround it with green (or perhaps a darker cool tone), whereas the photographer grasps at the saturation slider and moves it to the right (often just too far to the right). Perhaps just trying to use the light, within equipment limitations and means of reproduction isn’t enough. Colour is a relative issue we may need to take care of colour mix. just like we need to  compose a photo in the viewfinder, rather than expecting post-processing and perfect calibration to deliver rich colours.

.…Henri Cartier-Bresson wrote in 1975 about this issue

“we do not have yet have the chemical processes that permits the complex breaking down and reconstitution of colour (in the pastel range, for example, the gamut of green is made up of 375 nuances!)”.

Pigments and dyes and the surfaces we can print onto have improved a little since then but we are still looked into the same “constrained” mindset in a lot the digital photographic software and tool. Artist today don’t seem to be so restrained and frequently stray into gorgeous colour schemes without concern for media they are using or the intensity of the colour, but they usually understand the illusion of how the colours work together.

Any talk of colour always brings you to colour theory, (and yes I have spelt colour the correct way), but theory is in my view the wrong word here. What we know as colour theory, the colour wheel, complimentary and harmonious colour schemes is really more a practical guide to mixing colours beginning with primary colours (red, yellow & blue). Trouble is there can be many exception. The knowledge that colour could be both additive (in light) and subtractive (mixing pigments), dates back to Issac Newton but it was the German poet and thinker Goethe that formalised the colour wheel (his wheel in on the right) and introduced the idea that colour had a theory.  This colour wheel web app, is meant for web designers but it is immediately useful to both artist and photographers, the Kuler tool in adobe’s creative creative can now go one step further and pick colours off your photo.

 

Perhaps it is time photographers demanded some better colour tools.

With special thanks of Jessica Hische of Daily Drop Cap for the wonderful start to this post

Towards Blue(r) Sky(s)

Original (Polarizing)	Increased Saturation	Decrease Luminance
The light in summer here in Australia is very intense and it is really hard to get a decent blue sky. So I normally have a polaroid filter screwed on the front of my camera from November to April. The filter works a lot like the sun glasses, at different angles they will filter out and cut the intensity of the light. By rotating the filter you can see the darkening. As well as helping darkening the blue of the sky versus gulls or clouds, the polaroid can also work like a mini neutral density filter, to give you a slightly longer exposure on some landscapes.	The common approach is just make the sky bluer by increasing the colours saturation. In Lightroom you’d go to the develop module and slide the saturation slider to the right. Notice the gulls beak is also a more intense yellow	This is a less obvious route, In Lightroom you can go down to colour adjustment and in the HSL tab go into the Luminace panel and hold back on the blue a little. This just darkens the blue only and leaves the tonal range and colours on the gull untouched.