Colour Consistency – was it more achievable before digital photography?
Colour consistency – was it more achievable before digital Photography?
A lot of problems occur in colour consistency these days due to misunderstanding of calibration, use of colour space and conversion between colour spaces. I have often heard photographers comment that analogue methods of film and print were a lot more reliable for showing how the colours of an image should be represented. A photograph or transparency will not change colour, whereas a digital image may look different depending on what monitor or device it is viewed on.
As someone who worked in a darkroom dealing with professional photographers early in my career I can definitely say that the above argument is not completely true. Colour calibration problems with accurate viewing of colours has always been there in one form or another, whether dealing with film and print or digital images.
Colour consistency in traditional photography
Below are a few ideas used to achieve tonal and colour consistency when dealing with film and photographic print:
These include film, paper and chemicals and form a solid foundation if high quality is needed. Possible areas where quality may drop is if film or paper is old or not correctly stored, making sure chemicals are adequately replenished and making sure working areas are as close to 100% light-tight as possible. Small amounts of light will not always cause obvious fogging, but will reduce the punchiness of the final result. The use of a densitometer will highlight problems caused by chemicals before they become visually obvious and help in maintaining colour consistency. I used to operate a densitometer to maintain quality on an E6 processor. It involved taking readings from a test film strip, plotting a graph and sending the results off for analysis.
It is important to make colour judgements for prints or transparencies based on consistent viewing conditions and a neutral light source. This means looking at prints under daylight bulbs or daylight fluorescent tubes. The colour temperature of fluorescent tubes changes as they get older, so they will need to be replaced regularly.
Transparencies need to be viewed on a lightbox with a neutral colour source.
If transparencies need to be matched up to prints a special viewing hood is needed where the backlit/lightbox sources and reflective overhead light sources match.
As you can see maintaining colour consistency in the pre digital days still needed a considerable amount of effort, time and expense. Having said that, when things did go wrong it was not usually as pronounced as colour problems in digital photography.
Colour consistency for Digital images
Colour consistency in digital photography starts with accurate viewing conditions. This means having a good quality monitor that is regularly calibrated, as a starting point. “Good quality” in this case, doesn’t necessarily mean a huge, high definition 4K monitor. More important factors are colour accuracy, tonal and colour consistency in different areas of the screen and viewing angle. It is possible to spend a huge amount of money on a monitor and still not get the best colour accuracy. Eizo and NEC make good quality monitors for Photographers, retouchers and graphic designers. Here’s a link to the Eizo range of monitors. I use the Eizo CG246 which is very quick to calibrate via the built in calibration tool and gives me confidence when making colour and tonal corrections.
Monitors cost significantly less without built in calibration, but if you go for this option I would recommend buying an external calibration device such as the i1 Profiler. You’ll probably save some money overall, but spend a bit longer calibrating your screen. The accuracy of calibration is very good whichever you go for according to all reports I have read.
If you’re not familiar with monitor calibration here’s a rough guide to how it works. The calibration software has a series of colours which it displays on your monitor, one after the other. These colours are measured, either by an external device such as the i1 Profiler, or your monitor’s built in device, which pops up only during calibration. These measurements are compared with the values of the colours stored within the calibration software and a colour profile created which corrects any inconsistencies.
If you need to print from digital images you may well need to give printer calibration some thought. Some solutions are beyond the budgets of most individuals. Conversely some printers give decent results out of the box without spending any additional money, providing you use good inks and paper. Most people using prints for personal use don’t feel a need for calibration.
If on the other hand you’re a commercial printer churning out tens of thousands of copies, or if exactly the right colours are important, any inaccuracies could be very costly. Calibrating a printer will improve things, but you need to bear in mind that some colours seen on a monitor cannot be reproduced on paper however good your calibration.
Remote calibration offers a relatively cheap solution if you have a lower budget. It involves downloading a colour chart, printing and sending it off. Readings are taken to produce a colour profile. This file can then be sent to you to be placed in your colour sync profiles and selected from your print dialog settings. The colour profile will be specific to your printer and paper type. A different profile will be needed for each paper type you use and each printer.
Some companies very conveniently offer an onsite calibration service, which is very popular if a little more expensive than remote calibration.
For those who need a consistently high level of colour accuracy the solution is to buy a spectrophotometer to create your own profiles. Prices vary from about £300 to £1000. For this you will get the convenience of being able to calibrate whenever you need.
There is a huge variation in the price and quality of scanners. At the lowest end you can buy a multifunction printer for under £100. In my experience the scanning function on these tends to produce over saturated colours with detail being lost in the dark areas of an image. They are often more relevant to text and graphics rather than photographic images.
At the other end of the scale are the Hasselblad Flextight Scanners (formerly Imacon), which sell for somewhere in the region of £16,000 and are clearly aimed at the professional market. I worked for many years one of these, building a digital archive of a photographer’s huge library of 5×4 transparencies and negatives. I haven’t come across any other scanner I would prefer to use for a job such as this.
If you want to reproduce the subtle balance of colours and tones of a photographic image choose your scanner carefully. For personal use I think the scanner function of the Epson xp850 produces good results at reasonable budget.
Most scanning software these days lets you alter the colour as you scan in. So is calibration necessary for a scanner? As with printers I think it depends largely on how important accuracy is to you. There is a subtle relationship between colours and tones in a photographic image. An uncalibrated scanner can upset this relationship, which is difficult and sometimes impossible to compensate for with the more general colour and tonal adjustments offered by the scanner’s software or any image manipulation software used post scanning. In addition you may also find you need to make a different adjustment to each image as the range of colours in each image are different. This means a calibrated scanner will also save time.
Calibrating a scanner involves scanning in a specific image or colour chart, which is then compared to a digital copy and any differences used to generate a colour profile.
Has the digital revolution been good for photography?
I have always worked at the post shooting stage and feel that my job is hugely more creative and enjoyable since the digital revolution. So for me the answer to the above question is definitely “yes!”. The ease of being able to make alterations to digital images is a good thing, but does throw up a new set of problems. Consider for example, an image that has been carefully colour corrected by the photographer on a calibrated system to match the mood they want and the original colours as they saw them. This same image may be altered by someone else to look good on their uncalibrated monitor and sent off to the printers, giving an unsatisfactory result. It is therefore important for anyone dealing with images in a professional capacity to be reasonably well educated when it comes to colour management.
Other consequences of the digital age are an expectation of a higher volume of shots, faster turn around times and in some cases a struggle to maintain standards of quality. These expectations could not be met by a photographer who chose to shoot on film. With the accessibility of digital photography providing cheaper alternatives, I feel that the value of the professional photographer has been devalued somewhat. It may be easier to set up as a photographer these days, but it is more difficult to earn a high wage from it.
As traditional methods of photography become a distant memory it will be more difficult to make comparisons such as these. I have witnessed a lot of changes in my career, seeing some photographers thrive and other choose alternative employment. These are my opinions based on my experiences. If you have any comments or differing experiences I would be glad to read them.