Why are my prints too dark ?
This is probably the most common question photographers ask when trying to match their prints with their screens. Invariably the people who are having problems with this issue aren't having a general problem with overall dark prints, but that their darker (and mid) tones are too dark, but highlight areas are usually quite acceptable.
There can be several contributory factors that can give rise to this problem, but the most common single cause is actually more simple than most people realise; Their monitor is set too brightly.
Let's explain that in more detail.
When you're working with photographs on a computer knowing what is "right" can be a tricky business, all you're really working with is numbers in a data file that only become a photograph when displayed or printed.
There's often a misplaced assumption that the monitor image is somehow "right" and the print is wrong, but how can you be sure ?
Too many photographers simply unbox their computers and start working with them without considering if their monitors are set up correctly and displaying the image accurately.
Monitors often have high default light outputs to make them "punchy" and attract attention in the computer shop. The maximum brightness levels are often quoted in sales literature that gives the impression that high output levels are somehow to be desired, although this is often counter productive in delivering high tonal accuracy for photographic work.
The problem has been exacerbated with the increasing take up of flat screen monitors, compared to the old tube monitors used in the past. These monitors can deliver very high light outputs as sought for domestic television viewing and are often promoted on the brightness of the screen, which may be a useful feature for people working in bright offices on text documents, but less useful for photographers who are striving for tonal accuracy.
An unfortunate side effect of these bright screens is they aren't as accurate at lower output levels and usually exaggerate the tonal separation in low level shadow and mid-tone ranges. This means that some cheaper flat screen monitors are incapable of accurately displaying low level tones irrespective of how they are set up.
It's interesting to note that the most expensive monitors promoted for graphics work don't claim high light outputs or huge contrast ratios, but promote themselves on the quality of their output and a wide gamut range instead.
Another important aspect to this problem is physiological. Your brain is clever and always tries to expose your eyes correctly. We need to remember that we don't look at printed images in the same way as we view computer images when we will sometimes look at small areas of the image highly magnified completely isolated from the rest of the image. So if you fill a screen with low level shadow detail your eyes adjust to the low levels to reveal that detail. If the whole image was viewed, rather than just an isolated section, your eyes then expose for both highlights and shadows and that dark detail wouldn't be as apparent.
It's worth trying an experiment by viewing a normal image with a wide range of tones backed by different coloured surrounds on your monitor.
If your editing software has a full screen view use that to remove any distracting screen clutter and view the monitor from far enough away so that you can concentrate on the whole image, not just sections of it. Ensure that there is a wide margin around the image then change the background colour, look way, then view the image. You'll see that when the surrounding colour is bright low level tonal details seem less obvious as your eyes have balanced their exposure for everything in your field of view, conversely if the back ground is dark, shadows will seem more open and detail will be easier to see.
Another interesting experiment is to watch how the general tonal appearance of images can change as the size of the image changes. A thumbnail image in a browser often appears darker than when the same image fills the screen.
How to solve, or at least reduce, the problem.
Setting up monitors has two basic components to the process.
Firstly setting the luminance (light output) of the device, then adjusting the colours to ensure they are displayed correctly.
We would strongly recommend that you purchase a proper monitor calibrator like the X-Rite Eye-One display or Colorvision Spyder to help set up your monitor. This type of product will allow you to accurately set up and calibrate and profile your monitor and ensure that any changes in the monitor's performance are compensated for. Setting monitors by eye is almost impossible. We've found that the monitor on-screen menus vary greatly from model to model. As an example our own NEC Spectraview monitors gives an accurate image with settings of around Brightness 53.8%, contrast 50%, whereas a recent customer using a Samsung screen had to drop his brightness down to just 10% to get an accurate match.
A database of settings can be seen on TFT Review's page.You'll see there most on screen display brightness settings are 40 or lower.
Firstly carry out a proper hardware calibration of your monitor and set an appropriate screen luminance. At this point we need to start putting numbers to the settings. Good calibration software should allow you to specify what luminance level your screen is set to, the exact figure will depend on how your prints will be viewed.
Figures around 100cdm² will be ideal, possibly as low as 80cdm might be appropriate if the lighting condition you view your prints under isn't very bright.
If possible us a gamma option of L* (perceptually linear response curve) in your calibration software, unfortunately there aren't many packages that offer this yet so the best alternative is a gamma value of 2.2.
Colour temperature is best targeted at D65 for most non-commercial press work.
Initially this may seem a dimmer screen image that you're used to and will seem "wrong" as a result. Stick with it though, once your eyes become accustomed to the lower output you won't see it as "wrong" and may even find the screen less tiring to work with for long periods.
The downside to this is that once a lower and more accurate screen luminance has been established you may find that some images edited on a high output screen in the past now look wrong and too dark, but they will probably start to match the "problematic" prints!
Colour calibration of the monitor with a hardware device should correct, as far as is possible, any deficiencies in the reproduction of the graphics card and screen, but relies on the correct settings for the screen's luminance output. Unfortunately some low end monitor profiling hardware and software doesn't offer the option to set specific luminance values. Unless you take care to get the luminance output of the monitor correct before running the profiling software you can still run into problems with too high a luminance output from your monitor.
Once the screen is calibrated and profiled you should have a better benchmark to work from, however you will still need to appreciate the differences between the illuminated screen and the reflective print.
One trick that can help evaluate the screen image is to step back from the monitor so that your eyes take in all of the screen and image in one glance, then you may see that darker tones more closely match the printed output.
No system is completely perfect. Cheaper monitors may simply be incapable of accurately displaying some tones or colours, so take the time to understand where the limitations of the systems are and take these limitations into consideration when preparing and assessing images for output.