Building a Digital Colour Wheel

Most of us are familiar with the conventional colour wheel. It is the colours of the rainbow wrapped around and joined at the purple/violet segments. It normally shows 12 colours, the primaries (Red, Yellow & Blue) then the secondary colours easily mixed from those (Orange, Green & Purple). Finally the six tertiary colours mixed from the adjacent primary and secondary colours. Whilst many people instinctively know a harmonious colour scheme (eg red & green, Blue & Orange, Yellow and Purple) They might find it difficult to describe why. The tradition colour wheel can come to the rescue here, colours on opposite sides of the circle are called complementary, beside each other are call analogous, In addition if one of the complimentary colours is left out but the analogous colours either side of the missing compliment are present then this is described as a split complementary. All these combinations are know to be harmonious (and desirable for an artist, photographer, home decorator or fashion designer). The colour wheel is very useful and you can read a bit more about Basic Colour Theory at Color Matters.

Some complications arise when you start to look at how cameras and TVs work. They use a three colour palette RGB (Red, Green & Blue). This doesn’t fit onto the traditional colour wheel very well (first image below). These three colours are also know as the additive palette. These three colours do work well in terms of how our eyes (specifically the three types of  “cones” in our retina) recognize colour. A lot of people not familiar with this system are very surprised at the lack of yellow, but if you add red and green light sources you will see yellow. Things get even more strange when you consider the approach developed by traditional colour printers (including your ink jet printer) which use the  CMY [K] (Cyan Magenta & Yellow) subtractive palette. The K in square brackets stands for blacK, as printers find they need a true black, because a mixture of magenta, cyan and yellow inks or dyes tends to be a muddy dark grey and leaves images flat. Black is not really a colour, but I wish to avoid the argument on that for now. It is even harder to fit these colours on a traditional colour wheel (there is no matching segments for Magenta or Cyan for a start). You can read a bit more on the RGB & CMYK colour systems at Colour Matters.

This is the point where I decided to combine these two palettes, and form 6 new primary colours. I’ve since discovered I’m not the first to have attempted this (eg see Warren Mars website) and this configuration is often known as the modern or digital colour palette, sometimes even the RGBCYM[K] palette.

You can then fill in the intermediate segments with new secondary colours to get a simple 12 colour wheel again. Amazingly if you employ the idea that opposite colours can be complimentary or adjacent colours analogous and you find they are also harmonious. What is going on here is the traditional colour wheel wrong? Perhaps for both their photography and printing aspects digital photographers might be wise to adopt or at least consider this new colour wheel. I will be discussing many of the issues for digital photographers in coming blog posts.

The very last image shows the colours Adobe Photoshop and Lightroom give you control sliders over. I’m still no closer to being able to explain this colour selection.

Photographing Artwork with a Copy Frame (update)

Somewhere along the line (with window 10 updates I suspect) lightroom became very flackey in tethered mode (at first I suspected the canon drivers, but installing updates just made the problem worse). Thus the benefits of my repurposed copy stand connected to the computer evaporated. It was back to clicking the shutter button. However I soon discovered using my little Olympus, with the tilt screen set up at a suitable viewing angle  could let me regain a little of the productivity. I could use the touch screen to both select focus and/or trigger the shutter.  So it was back to -

1. Position the art work.
2. Check the screen, perhaps refocus...
3. Tap the screen again to take a photo.
4. onto the next artwork…

Still considerably faster than scanning.

I like to use an mid grey background (matte board), to avoid the colour and/or tone biasing the artwork (particularly useful in preserving the white of the paper in sketches)

Using the OI.share app I can also set up my phone, Using remote control to get a live view from the camera, set all the key controls, focus and take the shot. All that is required is to set up the camera to connect to my phone via WiFi. I loose the screen view on the back of the camera but can see everything on the phone. I’m not sure it is any faster than just using the touch screen but it does remove the possibility of moving the copy stand as I tap the screen. It is also a bit of geeky fun, think of it as wireless tethering to your phone.

One big advantage of using OI.share on your phone is you can then post the captured image directly to instagram from the camera (and/or go through snapseed if you want to incorporate edits )

Yet another Reason to Photograph Art, rather than a scanner

I’ve been using the built in scanner in my HP Photosmart printer (an A4 typical all-in-one style inkjet) for my INKtober works. However yesterday’s included some Fluro acrylic paint to match my grand daughters pattern on her school art project (a hand painted mould of her hand), I a strang loop self reference sort or manner I decided to use that as my subject for my INKtober sketch for today,

I remembered that I had had trouble scanning the fluro colours before (on my beach people project) so I also took a photo (under artifical light). The differences are again shocking!

I probably should have waited for natural light and/or worked on the white balance but the camera (images on the right) gives a much better representation of the feel of my art work and closer to the true colours.

Towards a new Colour Wheel, but Why?

For a while now I have been bending the ears of my colleagues and friends incessantly about a “digital” colour wheel with 6 primary colours rather than 3. Looking back in the blog post I  hadn’t posted anything in here (yet!) So now is the time to fix that.

	Adobe Primary & Secondary Tertiary Red Red Red Orange Orange Orange Yellow Orange Yellow Yellow Yellow Green Green Green Aqua Blue Green Blue Blue Blue Violet Purple Violet Magenta          ? Red Violet

I started to personally  question the colour wheel adopted by adobe ( within lightroom and photoshop) for their omission of some colours in their digital post processing. It only gave me 8 colours, halfway between the convention 6 primary & secondary or the 12 primary secondary & tertiary colors I expected)?

Why have they done that?

So I looked at the ways are colours are handled in the camera, computer screens and then onto printers. Well they are not even in the same colour spaces, or built using the same colour models. Cameras and Computers screens (and any direct transmission of light) follow the RGB (Red Green Blue) colour model.  This an called an additive model of how colour works, because different wave lengths of light get added together. This somewhat matches the rods in out eyes which give use colour perception. We can only discern colour because different cones in or retina can detect different wavelength. If you mix projected light of these three colours you get pure white. Ok good but should that be yellow rather than green (green is a secondary colour isn’t it?). Damn if I mix green and red light I can get yellow?

Things get even more bizarre when you start looking at printing colour.  Traditional three colour printing and many inkjet printers use a different set for their primary colours (CYM) Cyan Yellow and Magenta! This is called a Subtractive colour model because certain wavelengths are removed from the reflected image. What is going on here? When in comes to reflected light and pigments mixing colour is again different, for example to get green you mix your light blue (cyan) and yellow!! If you mix all the three colours you get a dark muddy colour, close to black but not a true black. So many primers (and ink jet manufacturers) also use a per black to create the CYMK (K for black) scheme.

Close to a year ago I was doodling in my sketch book, and realized by combining these two colour schemes I had a new colour model with 6 primary colours. Not surprising, the idea of a RGBCYM[K] colour scheme has occurred to others and is sometimes called the modern or digital colour wheel.

I know I haven’t answered the big question why Adobe and many other photoeditors only give to eight color sliders. I can’t find out why (at the moment). This is a big topic so I will build and develop over several blog post to come.

Other Blog posts in here around the mysteries of Digital Colour Theory

• Building a Digital Colour Wheel
• Just How Many Colour Models/Spaces are there?
• Getting more Colours with Bit Depth
• The Gamut of Colour Spaces
• Chasing the Missing Colours
• Colour Names and the Martian Colour Wheel
• Luminosity and Tints & Shades
• Colour should be Fun
• Colour Calibration :: Before You Panic I
• Colour Calibration :: Before You Panic II

Putting Linux to work on my Air Gapped Archive

Yesterday’s realization about Linux, reminded me that I have an older computer dedicated to Linux, the Ubuntu flavour. I only use it occasionally (only 3 times in the last year) and its not connected to the Internet. Its my Air-Gapped Archive. However it is a very important to me. I use this older netbook to handle my photo Archive of original Photographs, including RAW images & photos of my art works.

I choose Linux for a couple of reasons. First the attempts to upgrade my little toshiba netbook to windows 10, initially half worked and progressively slow until an attempted system reset ensured it never worked in Windows again, but I found it worked well with Ubantu . Second Ubantu (and Linux) are Open Source, not propriety operating system so there is less chance of being depricated or abandoned.

I must admit I have only updated twice so far since setting it up and today will be the third update (effectively I’m averaging every 4 months (not 3 months) and that means each year I will be running through the full cycle of Son – Father – Grandfather. This year I’m using a series of Old Hard Disk, which I have reformatted and now I am copying on the complete back up set a fresh (from the external Hard drives (in this case in the red covers). Its not fast, I expect it will take about 3 hours to copy and verify approx. 2.7TB of data.

I have also downloaded a couple of programs to help me out if I end up with only the LINUX access at any time. These are Linux version of XNView MP, a cross platform version of the popular photo/movie viewer and converter, and DarkTable, an excellent open source photo editor, that is also available on several platforms including Linux. Both can handle jpeg and the three RAW format I have .cr2, .pef .orf, I feel happier being able to see my photos. Even though this archive is essentially a digital dataset, seeing it is the best assurance that it is a true archive.

PS I left the complete rebuild run over night and it seems it took closer to 6 hours o copy and verify 2.8GB of photos & videos

This came as a bit of a Surprise

I’ve a had a weekend of well meaning folk giving me a hard time because I avoid apple products, particularly the IPad and IPhone and most things “appleverse” (like calling their shop a “city square” and their salespeople “geniuses”). I’m not an apple hater. I still have my iPod, (even though its battery is shot and can’t be user replaced, an incredibly common design flaw in most apple hand held devices, giving them only a guaranteed 2-4 year life expectancy). I just think they are overprices and whilst they do a restricted number of things very well they are pretty inflexible at others… ok I’ll stop there because I don’t want the emotion rhetoric or flame war to start. Anyway it piqued my interest and I decided to look at just who looks at my blog. This is the summary graph by operating system produced by blogger, which hosts this blog

I was surprised! Even If I add together all the Macs, iPhones & IPads its a little over 15% of my readers. So the apple fanboys probably won’t be reading this anyway. What did stun me was the number 39% for Linux users. Obviously I assume I must appeal to the free thinkers, less conventional and nerdy types (or maybe just search bots) as well as the corporate world and more precisely those that can afford the cheaper PCs (windows user 38%). The lesser surprise is the also small number of phones 10%, whereas my website stats have shown viewing with a smart phone to be approaching 50%. Is this because blogger is a bit ordinary in mobile mode or there are no popular HTML “readers” for mobiles. Maybe I am not seeing the true picture, but perhaps it is good that I have avoided the “shiny new toy” syndrome that seems to just focus on gear, (most photography podcasts, you tubers, blogs, and owners of the latest apple gear) not how they can be used. It steels my resolve to return to the mission I started with this blog over 15 years ago, that is “Things They Forgot to Tell You About Digital Photography”.

Can you find the Kookaburra?

Taken on the Jells Park Photowalk :: Seeing as the Camera Sees.

This is a good example of my new approach to handling a (big) batches of photos without wasting time and waiting for (slow) software. (ie bringing the fun back into photography). Taken from the camera card with Photo Mechanic (180 images, 90 pairs of jpeg+raw), adding metadata, select and rating the best (under 3 minutes) then pumping 40 raw files out to photolemur 3.0 to see what is possible (another 2 minutes for that to happen, time to make an espresso) Then I sat down (5 minutes later) and choose half a dozen photos to work on.  All I had to do with this one was crop the photolemur output. Voilà.

Then I used Photo Mechanic Upload tools to send this cropped image to both flickr and twitter (in less than 2 additional minutes)

For a couple of photos I will go back and take them into On1 Photo RAW and three sets of 5 images each I will take into AuroraHDR 2019. Even though I’m not under any time constraint taking the chore aspect out of culling ranking and caring for my photos before I can even start the fun of enhancing things, give to time to reflect and hopefully lift my creativity

Missing Files after a Windows 10 Update, with the Benefit of Deja-vu

Microsoft could have avoided the brew-ha-ha over missing files, after the latest Window 10 update, if they had bothered to reply to any of my several reports on the problem (to their support sites), all ingored , back in the last update in June. There were probably several hundred others in a similar difficulties reporting to various forums, and microsoft was silent.

The reported discovery that the missing files was cause by the "Known Folder Redirection (KFR) which is supposed to help remove duplicate files, makes sense to me as it was files or folders I had recently been using that “disappeared” during the june Windows 10 update. So this is not really a new issue.

I had a good backup of my working files (on a mirrored NAS drive and a separate external USB drive). I discovered my own work around, just take the affect USB external drive to a different computer, and the missing files were visiable! However I had to go through about 6 weeks of angst and update distress.  Not to mention a total reset and reinstall all my software (and explain to various venders that I need to reinstall software on the same computer (ie without exceeding my install/sites limit). My trust in Microsoft was severely dented and I for one would be happy if I could say NO to any future windows updates. This latest admission is not helping me change my mind.

The big question is how are these problems getting through Microsoft’s testing and their much hyped Insider feedback system? I know, they probably ignored them as well….

The Sunset in HDR :: three ways

There was a half decent sunset tonight, and a perfect opportunity to test out a 5 bracket exposure and three different approaches to post processing the higher dynamic (and 32 bit colour) image in the new AuroraHDR 2019.

Firstly I really confirmed that the default tone mapping is pretty good (almost good enough by itself). However it was then easy with the adjustable Gradient filters to add a little vibrance and warmth to the top of the photo. Giving a result perhaps a bit closer to what I experienced. Then I tried a couple of presets (now called “looks” in Aurora HDR) and settled on Warm Landscape as the best match albeit perhaps a little too colourful. This is powerful stuff and a joy to use.

Playing with Looks & LUTS in AuroaHDR 2019

The new Aurora offers a many new capabilities, particularly in how it “prepares” RAW files to be merged by applying an AI (artificial intelligence) neural networks derived from how other photographers approached exposure, tone mapping and colour renderings of similar scences, to the individual input photos before they are combined. Rather than formulaic presets/filters applied to the merged and higher dynamic images after they are prepared. The difference is a bit like an unseen black box process. There are a few aspects however of the new Aurora that make themselves very obvious to the user. These are looks (the new name for presets) and LUTS (look up tables).

I thought for now I would just show how much these can affect a single input photo of some native flowers. They are all achieved with a single click once the input image is tone mapped.

First look at AuroraHDR 2019

I had been eagerly awaiting the release of the update to Aurora HDR (AuroraHDR 2019) particularly to see what use Skylum would be making of their AI capabilities (Quantum HDR engine). I was impressed but also a little surprised!

I needed to use the anti-ghosting selection because the girl on the path is walking towards me and the leaves on the trees were blowing in the winds. It worked well.

The way the AI  enhancements are applied is individually to each image before they are merged (a surprise but probably the best approach). However this slows the merge process considerable as the program goes through the following steps (at least it tells you what is it is doing, where several other programs just show a static screen and make you wait.

• Loading Images
• Detecting Scene Type
• Detecting Scene Objects
• Improving Dynamic Range
• Enhance Image Structure
• Improving Colour
• Final Touches to make it Awesome*

i*after the google+/google photo failed attempts at AutoAwesome, I’ve been sceptical of any awesome claims]

The wait is worth every bit of the delay. The default tone mapped image was really great, (I refuse to use the word awesome) and the tiniest amount of adjustments to smart tone, highlight and shadows, then straightening and cropping gave me the wonderful results below. Pretty dare good for a first run through.

Marvin returns for INKTOBER inspiration

Marvin : Mate how about cleaning me up and colouring me.
Norm : But I'm not suposed to use a computer for inktober sketechs
Marvin : I fell nude in raw ink
Norm : OK, Just for you.

B is for Burst mode

I haven’t really had the opportunity to test out my higher rate burst mode (continuous shooting) on the Olympus OMD EM10iii. Mainly I had not been in the desirable position of the sun behind me and a cross wind so any birds where taking off while they fly past as I panned. The magic happened late yesterday. Well the camera performed well.

I was shooting in RAW+jpeg and I got the above sequence in a little under two seconds. Not exactly 8fps as claimed but it does give a great range of the full graceful wing movement of a bird in flight. I’ve cropped in a little on the RAW versions, not perfect but I am impressed.

More on Photographing Art … with a Cameraphone

Anne-Laure Jacquart of “following the White Rabbit” on you tube has a couple of quirky but easy to follow video guides on the important steps using a cameraphone to photograph and post process your art (eg tidy up, straighten etc) and it is primarily oriented to getting your art looking its best when to posting on instagram or other social platforms.

It is worth following her around her flat and her fast french accented delivery, particularly how to best use natural daylight, where to find the good light and avoiding distortion by holding the camera parallel to the art. Lots of god advice explained by doing it.

In this second video she demonstrates the adjustments using snapseed, which can still be downloaded for free from both Itunes store and google play. (If you don’t have it yet now is a good time to try it out). However the steps can be applied is most image or photo editors around today,

I

If you are into watercolours and/or urban sketching, or just eed to get a creativity boost follow Anne-Laure on Instagram &/or YouTube

Could AI help Photographing Art

Well after all it is my new “toy”, sorry I should have said tool. Will AI (Artificial Intelligence) be of help when photographing art?

I have found that photolemur generally does better on the olympus RAW (.orf) files, and as I generally take RAW + jpeg I did have a RAW version of my multimedia sketch (I’d used in the previous comparison).

And It did! The creases are a consequence on my folding the original A3 to get the sketch to fit on my A4 scanner. Otherwise we are getting much much closer to the original,  improvement id exposure and colour rendering but not perfect reproduction yet.

Looking at Photographing Art Works (again)

I have known for a while that my conventional flatbed printer/scanner doesn’t do a particularly good job of photographing coloured art works. (BTW Its fine for ink line drawings such as cartoons)

Last night I went to a great talk by Wayne Degenhardt at the Watercolour Society of Victoria, about Photographing Art. This inspired me to take some photos of my multimedia sketch I created at the Discover Nature through Drawing workshop last week, because I was a little disappointed with the scan, it was flat and very pale.

The results shocked me!

I haven’t gone to a lot of trouble to make this a scientific comparison, the cropping and rotation are inconsistent for a start. Further, the results are all jpegs, straight out of camera with only cropping but importantly all taken under the same lighting conditions. Upper left is the conventional scan (on a HP 8110 Photosmart printer) The apper left is my Android HTC 11 Cameraphone. The lower left is camera on my HP Spectre Tablet. The lower right is the jpeg from my Olympus OMD EM10iii.

So which is best?  Well, none really! If I had to choose one it would be the cameraphone but i’d have to lighten and correct the colour f the background. I can see further investigation is required here.

How close is too close?

I had a great opportunity yesterday while walking on the wall of the Cardinia Reservoir to  test out the reach of  my new olympus OMD EM10iii camera, using just two lenses (14-150mm and 75 to 300mm) and a multi-image stitched panorama.