RapidStudios's Tip 7: Understanding colour

Understanding colour

Colour can be quite tricky, every device, due to how it’s designed and what components have been used, records and represents colour slightly differently. Colour representation is also very objective, most monitor and printer manufacturers all invest a lot of resources on getting their colour representation to “look nice”, moving away from a more accurate reproduction. We all prefer a nice looking image to an accurate image.

Common problems when taking and printing digital photos:

White balance:

If your camera is unable to properly select the right “white balance profile” images come out with a yellow or orange or blue tint.

You can try and choose a white balance profile in the camera’s settings yourself, or try correct the photos in Photoshop.

Blow out:

Print is toner dots on white paper. If there is a pure white area in an image no dots are placed, only the white paper is left, looking naked and crisp. You can fade smoothly between 100% dots and 10% dots, but between 1% dots and 0% dots you will always see the difference very clearly. For this reason it’s very important that there are no 100% white (blown out) areas in your photos. They don’t look nice at all. Many digital cameras have an option to highlight blown out areas when you preview the photo on screen after taking it.

Bad skin tones:

Skin tones are often very tricky as people are quite sensitive to be too dark, too red or too pale. There are many software packages available to correct skin tones. Correcting by hand can be troublesome for amateurs.

So what do we do now?

We here at RapidStudio put our priority into colour accuracy as opposed to “niceness” – this is best for photographers who have their devices calibrated and have expectations as to how their colour is going to come out and people with medium to high end digital cameras who don’t do colour touch-ups on their PCs. For the most part camera screens are pretty accurate, especially higher end cameras, while computer monitors, home inkjets and lab prints are usually not accurate but adjusted to “look good”.

Our advice:

• Avoid at all costs blown-out areas in your photos.
• If a photo looks too red or too dark on your camera’s screen, try do some touching up on your computer, just remember your monitor is probably not calibrated. You’ll probably notice the colour difference between your camera screen and monitor.
• Never save or use a CMYK jpg.
• Only use RGB files in your album (Never CMYK or Pantone).
• Trust your camera screen more than your monitor, printer or lab.
• If you touch up colour on your PC, make sure the monitor is on it’s default settings, try looking at it on other monitors to see if there’s a difference.
• Make sure you have the newest software

For the more technical - The main differences are due to the following.

Colour balance:

Different lighting conditions (sunlight, fluorescent or incandescent) produce a very differently tinted light. Our brain automatically compensate for these different tints, and in a similar way, the small computer in your digital camera analyses the image and selects from a set of predefined light filters that make the image look how it thinks is most correct. Look for grey balance, neutral balance and white balance on your digital camera.

http://en.wikipedia.org/wiki/Color_balance

Colour temperature:

Colour can be shifted to look “warm” or “cool”. Often people will use this colour temperature setting on their monitor to change the image according to their preference.

http://en.wikipedia.org/wiki/Color_temperature

Gamut:

Gamut is basically all the possible colours that the device can accurately reproduce. The larder the gamut, the more accurate the device will be able to display the colour, the smaller the gamut, the more likely it is that other devices will accurately reproduce the colour. As every device (your camera, your monitor or your printer and our press – even different batches of ink or toner and different papers each have a unique gamut.) has a different gamut, the colour will look different. This is obviously something we have no control over.

http://en.wikipedia.org/wiki/Gamut

NB! Colour mode:

While most digital devices work on RGB (Red Green Blue), printers use CMYK (Cyan, magenta, Yellow, Black). This means that the colour has to be converted from one mode to another whenever you print, meaning the colour will change. Home printers have a small computer built into them that converts the colour. Each printer will have it’s own conversion software meaning each will convert slightly differently. The fact that there is a conversion means the colour will never be rendered exactly the same. For this reason most printing companies ask for their files to be supplied in CMYK mode, this means the customer has seen the CMYK image and have a more accurate expectation of what they’re going to receive. JPG image files are natively an RGB format. You shouldn’t really ever save a CMYK JPG file, while some software allows you to do this, it’s not at all good practise – if you need a CMYK file, save as a TIFF or a PDF. RapidStudio’s Photo software however only works with RGB JPG files. If you have CMYK jpg files the colour will not be accurately reproduced at all.

http://en.wikipedia.org/wiki/Color_theory

Backlight:

Your monitor has a backlight, rendering colours with a much higher luminosity than they could ever appear on paper. As your monitor ages the colour will also change.