Color Management – Equipment Calibration

Monitor color problems and monitor calibration

A picture is worth 1,000 words. How about three pictures? (A total of 1567 words in this article). Please read this brief intro section carefully to ensure that you know exactly what each of the three images depicts. Click the image to enlarge.

What you are looking at is side-by-side monitors on my desk.

  • They are connected to the same computer (I use dual monitors)
  • Each monitor is different in make, size and quality –
    • thus colors and sizes vary between them even though they are set up and calibrated regularly to be as identical in color as possible
  • They are each displaying this color reference chart opened in separate browsers, one on each monitor.
  • The images are intentionally out of focus to remove (blur out) jagged lines caused by photographing the monitor

#1 & #2 are both photographs as they came from the camera

#3 shows the result of post-processing photograph #2.

So – what does it all mean? I am going to use these three images to demonstrate why capturing good color in your camera, in & of itself, is meaningless unless your monitor is calibrated. We’ll follow that up with a consideration of the ramifications of the monitor color problem on a print. Isn’t it a shame to waste the time, effort and expense in getting a great image if we can’t display it properly? It sure is.

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Image #1 shows the color reference chart on two calibrated monitors. Note that even on properly calibrated monitors the colors are not 100%  identical. The monitor on the right is older and is at the limit of its color “adjustability” due to age (and is not used for color critical work – just things like email & text).

Image #2 shows the chart after I completely “ruined” the color calibration on the right hand monitor (the things I do for this course ;-)). I changed the R/G/B percentages to 90/60/30 percent of their calibrated settings. This gives the overall color a warm cast (high in red content and low in blue as compared to the correct settings). Note that the chart on the left hand (calibrated) monitor remains the same as it was in #1.

Here’s the situation I’d like you to imagine. You took a picture of a paper copy of this color reference chart (available) and nailed the colors perfectly. Further, assume that you have just a single monitor (nothing for comparison except an actual copy of the reference chart).  Your single monitor is the one on the right above. If you looked at your photo on a calibrated monitor, what you’d see is as shown in #1 (and, since you nailed the colors , that matches the copy of the chart that you’re holding in your hand for comparison). Now instead, suppose you looked at it on an uncalibrated monitor like the right hand one in #2. In comparison with the chart you’re holding there is no comparison. Something is wrong color-wise. You have two major decisions at this point –

  1. You can decide that your monitor needs calibration and do that before doing anything further with your images, or
  2. You can decide (for whatever reason) to accept the monitor calibration (colors) as they are

If you made the 1st decision, your problems are over. If you made the 2nd, they are just beginning. Let’s follow along with the 2nd choice and see where that leads

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You’ve decided that rather than recalibrate the monitor, you are going to make post-processing color adjustments to your image (which, recall, is perfect in color; it’s the monitor that’s wrong). You load the image into your post processing software and the chart appears – with colors just as in #2. You proceed to make adjustments  as you try to bring the chart’s colors in line with your paper chart that you have in front of you; you’re trying to get the right hand display (chart portion ONLY) of image #2 to look like it does in #1. Image #3 shows a possible result of your attempts.

Look at image #3. Think back to the color problems introduced into this monitor – in particular, the blue component was turned way down. You can see this in image #3 where, in order to get the chart somewhat normal, lots of blue is being added back. You can see this in terms of the effect it’s having on the rest of the image (the non-chart portions). Now, look at how much the chart on the left of #3  has changed.

In our imagined scenario, you see nothing except the right hand monitor in the real world situation. The left monitor in image #3 is added solely to demonstrate what your attempt at post-process color correction is doing to the REAL image. When you save your once correct file with these corrections that you just made, these new colors are correct for only one condition – when viewed on this specific uncalibrated monitor. Now – go load your “corrected” file on a calibrated monitor. What do you think you’ll see? If you said “The chart with colors as depicted on the left monitor of image #3“, you’re right.

Look at the bottom row of the chart. That row is supposed to be neutral in color – white, grays, black. Neutral is how it is on the left screen in images 1 & 2. Add some blue to “fix” the color problem while using the right hand monitor and see what you’ve done. The neutral colors in image #3’s left monitor all have a blue cast. That’s your final image as it will be seen by anyone with a calibrated monitor.

By choosing to correct the colors in your image file (that’s what post-processing did – it changed the colors and substituted them for the correct ones in your image file) – you’ve ruined your image. Unless you saved a duplicate of the original (or used “Save as” after your corrections) it’s gone forever. A terrible, terrible decision you made in not calibrating the monitor.

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Monitor Calibration – How do you calibrate a monitor? Read this. I use this device – detailed description and illustrations are here. The HH club should consider purchasing one for members to use.

Let me observe at this point that most monitors aren’t as poorly calibrated as our example. However, with the right (wrong?) combinations of subjects & color it doesn’t take much to throw things off enough to be easily visible – especially when you go to print (see next section). Take the time to calibrate your monitor and keep it calibrated. This isn’t something you do once and forget. Monitor colors “drift” and require recalibration regularly. I do mine every four weeks; professionals do theirs more often. “Never” isn’t often enough. There are lots of sample tests to get an idea of how well your monitor is calibrated. Look at sites like this one (especially good, LCD monitors only) or this one.

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It gets worse! How can it get any worse? It gets worse if you print your new file. Assuming your printer is calibrated properly, guess what your print will look like (besides terrible)? If you guessed that it would look like the chart on image #3’s left hand monitor, you’re right.

See how the color problems just cascade as you go from camera to monitor to printer. However, if you get the first two parts – camera & monitor – right and then take the file to a reputable printer you should have no further problems. Costco, believe it or not, is excellent and reasonably priced (cheaper than I can print at home), but your results may vary from store to store; right now Manassas, VA is great.

I’ll leave printer profiling, paper, ink and the rest go until towards the end of this course. If you take care of the color in your camera and ensure that your monitor is calibrated, the printing will largely be OK. If you don’t, nothing further I can say here will help. A few thoughts though –

  • Printer profiles are unique for every printer, paper, and ink combination
    • A profile is a “Rosetta stone” that translates the language of color
      • Suppose I want red (R/G/B = 255/0/0) to be printed
      • The profile knows for this printer, paper, ink combination how to make the printed color match 255/0/0
      • Change any one of the three – paper is the most typical – and the profile must be changed
  • Visit Dry Creek Photo (mentioned in the color management intro) and look at their free printer profile downloads for Costco
    • There is a different one for every store even though most use the same make/model printer
    • At a given store, there is a different profile for every different paper
  • This is why when you print on your home printer you are asked what type of paper you’re using
    • Every paper has its own unique profile
  • If you use 3rd party inks, there’s another possible error source as inks affect profiles
  • BOTTOM LINE, follow the guidelines I’ve laid out for camera & monitor and then take your prints that matter to a commercial printer unless you’re satisfied with the the prints from your home printer. I use an Epson 3800 and am delighted with my prints – but that’s nearly $1300 worth of printer (and over $500 when it’s time to refill the ink – which fortunately isn’t often. My cost – paper & ink – runs higher than having Costco make the print, but it’s worth it to me for reasons like paper selection and control over the entire camera to printer process. Not necessary for most amateur photographers.)