The JPEG format is popular because images can be compressed to reduce their size, but the quality of a JPEG image will degrade if it is edited and saved multiple times. It's better to edit and save your images in the TIFF format, and in this article I'll explain why.
JPEGs Are For Sending
Most digital cameras use the JPEG format to save the images you capture. The advantage of a JPEG is its relatively smaller file size. JPEG images are compressed substantially so more can be stored on the camera's memory card and downloaded to your computer faster. The smaller size also makes JPEGs the best choice for emailing or uploading images. If you are sending someone an image of your artwork, a JPEG file is what you want.
But the reduced file size comes at a price. When a JPEG image is compressed, some of the detail is lost because the algorithm used to make it smaller is "lossy". The more the image is compressed, the more detail that is lost. Fortunately, you aren't likely to notice the effect of the compression if you use the highest image quality setting on your camera or when saving the file on your computer.
However, each time you open the image on your computer, edit it, and then save it as a JPEG, you are compressing it again and losing more of the detail. After repeatedly editing and saving the image, you will start to notice the cumulative effect of compression on its quality.
... TIFFs Are For Editing
The TIFF format provides an alternative for editing your images and is supported by most software. TIFF is a "lossless" image format, and the quality of a TIFF image is not affected by repeated editing and saving. This makes the TIFF format the right choice for images that will be edited further.
The first time you open a JPEG image to edit it (to crop or correct the color, for example), immediately use "Save As" to save the image as a TIFF file in a different "working" folder. Use this file as your "master" image for any editing. Never edit your original JPEG image because many changes you make cannot be undone later. Instead, make all of your edits to the TIFF master image.
Save The JPEG For Last
Eventually, though, you'll need a JPEG image to send to a gallery or submit to a juried show. And the best way to prepare that JPEG is from your master image and only when you need it.
Open your master image, resize it for the intended use (or according to any instructions you received), and save it as a new JPEG image. Be sure to save the JPEG as "Baseline (Standard)", not "Progressive", and use the JPEG Quality setting in the software to adjust the file size (usually between High and Maximum). You're done! Now you have the JPEG to send, and you still have your master image for future use.
So edit the TIFF image all you want, but save it as a JPEG last.
And click here to learn more about TIFF and JPEG formats in the Learning Center at ShootMyArt.com™.
June 30, 2008
June 16, 2008
The Colors Look Dull and Muddy
Have you sent a nice digital image of your artwork to the printer for a show and the postcard came back with dull, muddy looking colors? It happens all the time, and in this article I'll explain why.
RGB In
Since the late 1920’s, scientists have developed a variety of mathematical formulas – or models – for defining the individual colors we can see.
Computer screens, digital cameras, and scanners use an "RGB" color model, which combines Red, Green, and Blue light in varying proportions to produce other colors. This is an "additive" model because equal amounts of red, green, and blue light added together produce white.
Commercial printing uses a different model, "CMY", to produce the color in printed images using Cyan, Magenta, and Yellow inks. This is a "subtractive" model because ink absorbs light that would otherwise be reflected off the paper. An equal amount of the three inks eliminates all reflected color and produces black.
In practice, though, black ink also is added to provide the detail in a printed image and to produce neutral grey tones and a true black. The combination often is referred to as "CMYK", process color, or 4-color printing.
... Garbage Out
The color of a pixel in an RGB image is determined by three numbers, or values, representing the intensities of red, green, and blue light. The same color in a CMYK image is represented by values for the amounts of cyan, magenta, and yellow ink. Because the RGB and CMY models define colors differently, these values are not interchangeable.
And this is where the trouble starts. An RGB image must be converted to CMYK in order for the colors to be reproduced accurately. Printing from an unconverted RGB file will produce a printed image with dull colors that are somewhat muddy looking and darker than the original.
Nearly all of the images commercial printers receive are already CMYK and can be printed directly. If you don't tell the printer the image is RGB and ask about conversion, they are likely to assume it is a CMYK file. And when the postcard you get has dull, muddy colors, it probably means your RGB image was used without first converting it to CMYK ... Oops.
Ask And Tell
Converting images to CMYK requires some skill and knowledge of printing processes. Many commercial printers will make the conversion for free or at a nominal charge. If you're using a professional photographer or a graphic designer, ask them about converting the image to CMYK. Or try the conversion yourself if you are comfortable using Photoshop® and know what printing process is going to be used.
So, the problem is an easy one to avoid. Ask about conversion to CMYK and tell the printer if you're sending an RGB image. Otherwise, don't expect to be satisfied with the colors on the postcard.
And click here to learn more about color models in the Learning Center at ShootMyArt.com™.
RGB In
Since the late 1920’s, scientists have developed a variety of mathematical formulas – or models – for defining the individual colors we can see.
Computer screens, digital cameras, and scanners use an "RGB" color model, which combines Red, Green, and Blue light in varying proportions to produce other colors. This is an "additive" model because equal amounts of red, green, and blue light added together produce white.
Commercial printing uses a different model, "CMY", to produce the color in printed images using Cyan, Magenta, and Yellow inks. This is a "subtractive" model because ink absorbs light that would otherwise be reflected off the paper. An equal amount of the three inks eliminates all reflected color and produces black.
In practice, though, black ink also is added to provide the detail in a printed image and to produce neutral grey tones and a true black. The combination often is referred to as "CMYK", process color, or 4-color printing.
... Garbage Out
The color of a pixel in an RGB image is determined by three numbers, or values, representing the intensities of red, green, and blue light. The same color in a CMYK image is represented by values for the amounts of cyan, magenta, and yellow ink. Because the RGB and CMY models define colors differently, these values are not interchangeable.
And this is where the trouble starts. An RGB image must be converted to CMYK in order for the colors to be reproduced accurately. Printing from an unconverted RGB file will produce a printed image with dull colors that are somewhat muddy looking and darker than the original.
Nearly all of the images commercial printers receive are already CMYK and can be printed directly. If you don't tell the printer the image is RGB and ask about conversion, they are likely to assume it is a CMYK file. And when the postcard you get has dull, muddy colors, it probably means your RGB image was used without first converting it to CMYK ... Oops.
Ask And Tell
Converting images to CMYK requires some skill and knowledge of printing processes. Many commercial printers will make the conversion for free or at a nominal charge. If you're using a professional photographer or a graphic designer, ask them about converting the image to CMYK. Or try the conversion yourself if you are comfortable using Photoshop® and know what printing process is going to be used.
So, the problem is an easy one to avoid. Ask about conversion to CMYK and tell the printer if you're sending an RGB image. Otherwise, don't expect to be satisfied with the colors on the postcard.
And click here to learn more about color models in the Learning Center at ShootMyArt.com™.
June 2, 2008
Get Whiter Whites
As the laundry detergent commercial asks, "Do your whites look dull and dingy?" Can the same be said about the images of your artwork? In this article, I'll explain how to get whiter whites (and without using detergent).
White Is Not Always White
All light contains color, and the color of a light source is similar to the color of metal heated to a particular temperature. As metal is heated to higher temperatures, its color changes gradually from “red hot” to “white hot”.
Color temperature is the term used to describe the color of light and the relative proportions of yellow and blue in it (the "white balance"). Light from an incandescent bulb has a lower color temperature with more yellow in it. Direct sunlight has a higher color temperature with more blue in it.
The brain automatically adjusts to a wide range of different light sources so that we perceive a white sheet of paper as white regardless of the color temperature. As a result, we don't usually think about the color of light.
... Because The Camera Never Lies
But a digital camera records the actual color of the light. The white balance setting on your camera must match the light source to reproduce colors accurately. This setting tells the camera how to adjust for the color temperature of the light and avoid an undesirable color shift to yellow or to blue in the image.
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If you photograph artwork hanging in a gallery and the camera's white balance is set to "daylight", the whites will look "yellowish" because the incandescent lights in the gallery have a lower color temperature (more yellow). The upper half of this example shows the result. Similarly, if you photograph a piece of artwork outside and the white balance is set to "tungsten", the whites will look "bluish" because sunlight has a higher color temperature (more blue). This effect is shown in the lower half of the example.
An image with the correct white balance will have accurate color as well as neutral whites and greys.
Get the White Balance Right
Fortunately, the problem is easily fixed ... no detergent needed. Just find the instruction manual for your camera and learn how to set the white balance. Then remember to check it each time you photograph at a different location and change the setting, if necessary, to match the light source. If you aren't sure which setting to use or are photographing in mixed lighting (a combination of sunlight and interior light, for example), then set the white balance to "automatic". With this setting, the camera will try to figure out the best white balance and you'll be close.
So I'll end my version of the commercial with this tagline, "To avoid the embarrassment of dingy colors in your images, get the white balance right for whiter whites."
And click here to learn more about color temperature in the Learning Center at ShootMyArt.com™.
(The artwork “Lilies” is used by permission of Candace Law © 2001.)
White Is Not Always White
All light contains color, and the color of a light source is similar to the color of metal heated to a particular temperature. As metal is heated to higher temperatures, its color changes gradually from “red hot” to “white hot”.
Color temperature is the term used to describe the color of light and the relative proportions of yellow and blue in it (the "white balance"). Light from an incandescent bulb has a lower color temperature with more yellow in it. Direct sunlight has a higher color temperature with more blue in it.
The brain automatically adjusts to a wide range of different light sources so that we perceive a white sheet of paper as white regardless of the color temperature. As a result, we don't usually think about the color of light.
... Because The Camera Never Lies
But a digital camera records the actual color of the light. The white balance setting on your camera must match the light source to reproduce colors accurately. This setting tells the camera how to adjust for the color temperature of the light and avoid an undesirable color shift to yellow or to blue in the image.
.jpg)
If you photograph artwork hanging in a gallery and the camera's white balance is set to "daylight", the whites will look "yellowish" because the incandescent lights in the gallery have a lower color temperature (more yellow). The upper half of this example shows the result. Similarly, if you photograph a piece of artwork outside and the white balance is set to "tungsten", the whites will look "bluish" because sunlight has a higher color temperature (more blue). This effect is shown in the lower half of the example.An image with the correct white balance will have accurate color as well as neutral whites and greys.
Get the White Balance Right
Fortunately, the problem is easily fixed ... no detergent needed. Just find the instruction manual for your camera and learn how to set the white balance. Then remember to check it each time you photograph at a different location and change the setting, if necessary, to match the light source. If you aren't sure which setting to use or are photographing in mixed lighting (a combination of sunlight and interior light, for example), then set the white balance to "automatic". With this setting, the camera will try to figure out the best white balance and you'll be close.
So I'll end my version of the commercial with this tagline, "To avoid the embarrassment of dingy colors in your images, get the white balance right for whiter whites."
And click here to learn more about color temperature in the Learning Center at ShootMyArt.com™.
(The artwork “Lilies” is used by permission of Candace Law © 2001.)