DIY Calibration Chart

 A DIY Calibration Chart for Photographing Your Art (No Expensive Gear Needed)

Ever taken a photo of your artwork only to have it look completely different once it's online? You're not alone. Professional calibration tools from companies like X-Rite or Datacolor Spyder can help fix this, but they're expensive and actually only work on devices you control. The real problem is you have no control over how someone else's screen displays your image.

So, I created a simple chart to tackle the biggest issues that come up when photographing art for the web. It’s a low cost printable calibration chart you can use any time you photograph your art to be shared on-line.

Getting Started

Download the chart (as a .jpg file) and print it at 4 by 6" (10 by15cm) on photo paper. Choose matte or semigloss over glossy to avoid reflections. Any inkjet printer works, or take it to a photo print service like Ted’s, Officeworks or Harvey Norman.

You can use the chart before you shoot, or after, when editing. Fixing lighting issues before you shoot saves time and gives better results overall. Just place the chart on or next to your artwork, under the same lighting conditions.

Why Dynamic Range Matters

Dynamic range describes how much detail a camera captures from shadow to highlight. Your eyes handle huge contrasts easily, from sunlight to starlight, but cameras struggle. That's why bright skies blow out to white or shadows go pitch black in photos.

The chart has grayscale steps down each side, each representing a 2 percent shift in light intensity, plus small target circles for finer detail. The more steps you can distinguish in your photo, the better your lighting is working. If steps disappear into the background, especially on the darker side, add more light, but don't overdo it or you'll blow out the highlights.

With practice, you'll learn to spot overexposure (dark steps look too light) and underexposure (light steps look too dark) just by reviewing the upper or lower greyscale on the chart.

This trick works after the shoot too. Use your photo editing software's exposure, contrast, and shadow/highlight sliders can make changes on your photo containing the chart, then copy those settings to the rest of your batch. Thus you only need the chart in one reference photo per series where all the photos are taken umber the same conditions

Colour is trickier than tone. Our eyes adapt to lighting variations automatically; cameras don't. The chart includes seven reference dots, six colours plus black, representing the core building blocks of the sRGB colour space used in jpeg files. The table below show how each of the tiny coloured lights (red,green,blue) on your TV screen of computer monitor are lit up to get the given colour. Zero indicated the light is off and 255 that the tiny light is fully on. These lights then make up a single pixel within the photo image.

(255,0,0)         R            0 Red
(0,255,0)         G            Green
(0,0,255)         B             Blue
(0,255,255)     C            Cyan
(255,255,0)     Y             Yellow
(255,255,255) M            Magenta

After taking the photo, you could use a colour picker to compare your photo's dots against these values. This won't give you pixel perfect correction, but it'll reveal a colour cast. The main thing to watch for. Do the dots still look clean and bright, or dull and grey?

Dealing with A Colour Cast

Colour cast is sneaky because your brain corrects for it automatically without you noticing. Old incandescent bulbs throw a yellow-orange tint; overcast daylight can add a blue tint. Reflections from walls and furniture are often the biggest culprits, since your brain filters these out but your camera doesn't.

To check for colour cast, look at the white background behind the chart's colour temperature panel. If the white looks yellowish or bluish instead of neutral, you likely have a bias. The nine squares can help confirm this.The three colour squares of the same colour as the bias will appear brighter and/or stronger, while colour on the opposite side will appered duller or darker.

The fix is usually simple, find better light. If using artificial light, Daylight LED bulbs (around 5000k) are cheap and reliable. If using natural light, shoot in soft shade rather than direct sun, like near a window indoors, under a veranda, or in an open garage. A white board opposite your light source can bounce light back and soften harsh shadows.

When editing, use white balance, warm/cool sliders, HSL adjustments, or LUTs, always test these changes on your reference photo first before applying to the batch.

One Final Tip

Avoid the saturation slider orfilters when photographing art. They can make your image look garish, especially on screens where the viewer has already boosted their own contrast and saturation. If colors look flat, use the vibrance slider instead, and go easy with using it.

With this one printable chart, you can catch lighting and colour problems before they ruin your photos, and fix them quickly if they slip through. No expensive gear required.

Introducing a DIY Calibration Chart

Why You Should Calibrate Your Screens (And How This Little Card Helps)

Ever wondered why a photo looks perfect on your phone but flat and washed out on your TV or a print? It is not you. It is your screens. Even the best cameras, monitors and printers cannot capture or display the full range of light and colour that your eyes can see. That is where a simple calibration card comes in, and once you understand how to keep your equipment acceptably accurate.

Photographers talk about dynamic range, the span of light a device can capture, measured in stops. Each stop doubles the amount of light involved. Your eyes can handle around 15 stops. A good modern camera manages 9 to 11. Most TVs and monitors only reach 7 to 9, and even quality printers top out around 6.5.

That gap matters. When a device cannot handle the full range, it clips the extremes. Dark tones near black collapse into pure black. Bright highlights blow out into pure white. Detail and colour simply disappear at both ends.

Colour is its own puzzle, it doesn’t really exist as something physical, and there are two divergent interpretations of what creates it. How a device captures and reproduces colour is pure physics and maths of energy and light. How your brain perceives colour is much more personal, shaped by cognitive psychology and the lighting around you. Neither view is more "correct" than the other. The calibration chart will not give you laboratory precision, but it will nudge your average colour rendering and tonal contrast in the right direction.

Step One: Calibrate the Input (Your Camera or Phone)

Tonal calibration, getting the brightness and darkness levels right, is the single most useful adjustment you can make for realistic photos.

Look at the calibration chart and you will see a grey scale gradient running from black to white, with small grey rectangles down each side. On the right, the rectangles start light grey and get progressively lighter toward an almost white target. On the left, they start darker and step down toward a very dark target. Each little step represents a 2 percent shift in light intensity.

Here is the trick: point your camera or phone at the chart and check how many of those rectangles you can actually distinguish. You will probably lose a few, especially near the very dark or very light end. That is completely normal. Digital sensors simply cannot match your eyes' range, and cameras are designed to expose for an average middle grey tone anyway, so they will usually “clip” the extreme tones.

Start with your camera on an automatic exposure mode (A, P, or the green auto setting on a DSLR or mirrorless camera, or the default mode on your phone). Manual exposure is not necessary here.

Check the result somewhere you can actually see the screen properly. Camera and phone screens are notoriously hard to read in bright daylight, so review indoors or in shade.

If you can only spot a few rectangles on the dark side, the chart probably needs more light. If you cannot add light, try adjusting the exposure value (EV) on your camera or phone instead.

Advanced camera calibration (colour accuracy, white balance, lens distortion, sharpness) varies wildly between brands and models, so this card will not replace a proper colour profiling system. What it can do is flag obvious problems, like a consistent colour cast, or tonal issues worth investigating further.

Step Two: Calibrate the Output (Your Screens)

Now views a photo of the ca on your monitor, TV, phone or projector. This is where brightness and contrast come in, usually tucked inside a picture or display settings menu, accessed through a settings button or remote.

Start with brightness. Push it up and the screen gets lighter, revealing more rectangles on the dark side. Pull it down and you will see more detail in the light rectangles instead. The goal is a balance where you can see a good number of steps on both sides.

Next comes contrast. This stretches or compresses the range of visible tones. Getting it right is a bit of a balancing act between contrast and brightness. If you can see plenty of rectangles on one side but hardly any on the other, nudge the contrast up slightly, then pull brightness back to rebalance.

A quiet warning here: if you regularly use your screen in a bright room with strong light behind you, chances are your contrast is already cranked to maximum, which clips both ends of the tonal range. If that sounds like you, reset contrast to the middle, adjust brightness first, then slowly bring contrast back up while rebalancing.

Screen technology has changed a lot over the decades, from old cathode ray tubes to today's LED and LCD panels, and every manufacturer implements these settings a little differently. Materials also degrade over time, which is worth remembering if your screen seems duller than it used to be. When in doubt, the factory reset option is usually a safe, well calibrated starting point.

Step Three: Get Your Colours Right

Once tone is sorted, it is time for colour. Look for settings labelled colour, tint, colour temperature, hue, saturation or intensity, though the exact wording  and what bit changes depends on your device.

Saturation is often cranked up by default to compensate for ambient light, so check the row of coloured dots on the card. They should look natural sitting against the mid grey background, not artificially intense.

Many screens also offer picture modes such as vivid, natural, cinema, standard or eco. These bundle together saturation, brightness and contrast settings, so cycling through them is often the fastest way to find something that suits your eyes, though be aware they can override the careful brightness and contrast work you just did.

The chart itself has a colour temperature section running from warm reds, oranges and yellows through to cool blues and violets, sitting on a clean white background. If that background does not look properly white, you likely have a colour cast issue.

Small reference squares next to this section are arranged in 5 percent increments of colour strength. The top row handles colour temperature, from yellow through to blue purple. The bottom row handles “tint”, from magenta through to green. The middle row, goes from a red to a cyan .

To use them, simply check which square looks whitest against the background. If the background leans slightly green, for instance, a square on the magenta side will probably look closer to true white. That tells you which direction to nudge your tint control.

One last thing worth remembering: your room's ambient lighting will influence how you judge all of this. Do not calibrate for magenta while sitting in a room bathed in green light. Match your adjustments to the conditions you will normally be viewing in, and you will end up with a screen that shows your photos the way they are meant to be seen.

You should now have better screens to judge your images, that may be photographing your art, a portrait or to judge your results as you edit or modify your photographs with filters and app.

Another Microsoft favourite bites the dust

I thought I had put off any Microsoft updates for 5 weeks, but the updates happened last night. Maybe it was 5 weeks

It proudly announced that it updated itself and had five things to show me I don't think any of them were particularly new and/or exciting. They just wanted me to let them access my settings which I decided wasn't a good idea. The one thing I did immediately notice was that my phone link had a big message at the top and it wanted me to read the QR code on the screen. I had gotten used to using Phone Link and liked it.

Not unexpected, I had also updated my Android phone (I had trouble recharging my 7-year-old phone battery) and perhaps thought it was to do with a setting on the new Android phone. I did use Android Switch which worked quite well, and transferred most things. There were a few inputs required, I had to re-establish some connections with passwords etc. However the transfer was very smooth.

I aimed my camera at the QR code and clicked on the link, which took me to the site aka.ms (which is where you download the phone link segment for your phone), BUT, and it's a big but, it was a blank screen, so I tried again, investigated what response I could get, waited a while, then tried again and again. I could see from the display on my laptop it was still pointing to my old phone so I went and found it and made sure it was turned off. I went back to my phone and just typed in the address aka.ms to get to that URL. The phone seemed to think for a little while and then came up with a big red warning that my phone was not suitable because it wasn't connected to a VPN, which it isn't. The message also conveniently suggested that I could use Microsoft Azure as my VPN, and again no thank you. I don't really want Microsoft snooping on my phone as well.

If you're listening, Microsoft my trust in you is diminishing everyday

Can Watercolour Paper Deteriorate?

If you've pulled out a beloved pad or big sheet of watercolour paper only to find it's soaking up paint like a sponge, don't panic. You're not alone, and it's probably fixable.

Watercolour paper, whether cheap or expensive, cotton or cellulose, can deteriorate over time. There are two main culprits worth knowing about.

1. The first is chemical and/or biological damage. Acids from household cleaners, food smells, vinegar, even alcohol can drift through the air and quietly degrade your paper. Moisture give the opportunity for mould or algae, attracts insects or animals to stop by and snack. You'll usually notice yellowing, dark patches, tears, crumbling or even holes. Unfortunately, this kind of damage is pretty much permanent. there's not much you can do to rescue it. If this is effecting existing art work, especially if its precious, don’t attempt to fix it yourself seek out professional conservators. There are ways to improve the storage and display that can halt further deterioration.
2. The second culprit, the more common one, is the sizing breakdown. Sizing is the term used in paper making circles that refers to any substance added to or applied to the surface to reduce the absorbency of water. Most quality watercolour paper is coated with gelatine, the same stuff that makes jelly set. It's brilliant for painting because it holds moisture and pigment at the surface rather than letting them bleed deep into the paper. The problem is that gelatin is sensitive to humidity, temperature fluctuations, and light exposure. Humid environments or climates are particular culprits, but even leaving your pad on the back seat of a hot car can cause it to fail in patches. The result? Your paper suddenly behaves like blotting paper.

The good news is there are ways to bring sizing back. The simplest fix for the more expensive papers that will have both internal and external sizing is to wet the entire sheet, let it dry completely, and paint on it straight away. You can add the desired level you require in that new painting session. It sounds almost too easy, but it genuinely works, there are plenty of experienced painters who swear by it. The catch is you really only get one go at this, so time it well.

If that's not enough, you can re-size the surface entirely. Powdered gelatine is one option, though it's a bit fiddly. A more practical route is using a commercial watercolour ground.

I have found acrylic gesso also works well. Thin coats work best, I aim for two light layers, keeping the water content below about 30% to avoid bubbling and poor coverage. The dilution allows better flow/coverage and also gives you control over absorbency. More water leads to more absorbency, so a bit of experimentation and you can get back to something close to the original paper feel.

One tip worth trying: instead of a brush, use a small foam roller to apply the gesso. It leaves a fine, even texture similar to cold-press papers that's genuinely lovely to paint on. Especially if you're working with granulating pigments that like to settle into small dips and hollows.

So before you throw out that dodgy paper, give it a second chance. Chances are, it's not as far gone as it looks.

Towards Building the Perfect Sketchbook Holder

With a paint-out weekend in Castlemaine on the horizon for the Watercolour Society, it was time to build a sketchbook holder that could actually handle the job and coimg winter weather.

After two prototypes, I had a pretty good idea of what I was looking for. The foam core version was light and semi-waterproof, but it quickly buckled in the middle. The framing matte offcut held up better until it got wet. The sticky side of the velcro tape also caused problems by lifting the paper surface off the matte board rather than releasing the velcro, when I tried to remove my palettes. 

I found a sheet of 5mm craft wood (MDF) that was sturdy enough to do the job but light enough to hold in one hand. A couple of coats of acrylic paint should ensure the waterproofing. Then came the fun design tweaks. I added internal slots to hold bulldog clamps to nicely hold the sketchbook open. I slightly changed the shaped to better fit A5 sketchbooks in both portrait and landscape formats. Two rows of velcro and a felt bumper to keep my larger palettes snug and secure.

The result is a holder that keeps my sketchbook and palette firmly in place with one hand free to actually paint. Back to plein air testing.

More Nonsense

After spending hours last month untangling the mess Microsoft made by quietly inserting OneDrive into an active role on my Windows 11 machines, I thought I had finally sorted things out. OneDrive had been redirecting my Documents, Pictures and Videos folders into its own subdirectories and syncing them to the cloud, all under the guise of "backing up" my files. In reality, it was removing them from my control.

After some research, I restored everything to its proper location, removed OneDrive and the equally annoying Copilot, and delayed Windows updates as long as possible (note: Windows 11 Home users can only delay updates, not stop them entirely).

Then last week, updates from both Microsoft and Google undid much of my work. Copilot reappeared, desktop icons went missing, my machine started launching straight into Edge on startup, and OneDrive was back, once again redirecting my Documents, Photos and Videos folders to its own directories. Fortunately it was not uploading to the cloud this time, but the intrusion was unwelcome regardless. 

I am clearly not alone in finding Windows updates frustrating and error-prone. A NotebookLM "podcast"on the topic covers the issue well. I’m very conscious that AI generated content is frequently incorrect, just AI slop, however this is worth a watch.

 

Whilst on YouTube I found a video that explains specifically how OneDrive sneaks back through a backdoor Microsoft leaves open during updates, its longish and detailed with steps to keep it Microsoft at bay at least for now.

If you are running Windows on a computer or laptop, good luck! Make sure you keep a current backup of all your files at all times.

Plein Air sketching follow up

What Actually Worked (and What Didn't)

Over the past month, I’ve had a trips down to the Mornington Peninsula, Venu Bay, and I'm partway through the Plein AirPril challenge, whereby I’m supposed to do an outdoor painting every day in April. It has been a great chance to properly road-test my three DIY portable setups I'd been tinkering with.

The clear winner: the sketchbook holder

I haven’t used my tripod easel at all, but I’ve used the sketchbook holder constantly. It securely holds both my A5 sketchbooks, one with a hardcover sewn-spine, the other a wire-coil visual diary style. You slide the book covers behind the holder, fold the pages forward, through the slot and spread the pages to where you want and clip them with large bulldog paper clips on either side, and you're done. Even in the wind, it stays put. It's light enough to hold one-handed while standing, or it just rests across my knees when I'm sitting.

The whole setup takes almost no time: a pencil, a pen, a water brush, and my homemade CD dot card palettes. Done. It pays to be agile when the fickle Melbourne weather decides to throw storms, rain, wind gusts, but is mostly grey and overcast with occasional surprise sunshine at me all in the same afternoon.

The watercolour sketchboard: promising but …

I only pulled this one out a couple of times. It works, but it's heavier, slower to set up, and critically, the prototype was made of matte board. Getting drenched a few times took a real toll on it. The bulldog clip slots are a clever idea, and worth keeping in any future version

Lessons learned the hard way

Bag organisation matters more than you think. Rummaging around for that specific brush or pen mid-session is genuinely annoying. I've since started bundling brushes and pens in cord concealer spiral tubing and keeping them in small ziplock bags. Bonus is less disruption searching,

Using Velcro was trickier than it looks. Its holding capacity between its hock and loop surfaces is powerful. So powerful when I taped it to plastic palettes, the sticky backing kept pulling off surfaces as I removed the palettes. It was also lifting the paper surface off the matte board, strong double-sided tape and hot glue didn't work well either; PVC glue was slightly better. Still experimenting, looking for a heavy-duty version of this tape.

Keep your water brushes topped up. I nearly ran out of water mid-sketch one day. Lesson learned: empty, clean, and refill water brushes before heading out.

The spray bottle is actually pretty mandatory as well because it lets you keep whatever form of watercolour palette you’re using moist and the paint easier to pick up, especially with a water brush.

What's next

I'm planning to rebuild the sketchbookholder in plywood, with slots at the side to hold the sketchbook pages and a slightly bigger top flap for my larger palettes. For larger work or when using larger watercolour pads or blocks, I'll stick with my existing drawing board (the one with the tripod mount) with a camera tripod for a proper travel easel setup.

Overall?  Happy with how it went. Sometimes the simplest, lightest setup really is the best one.