All You Need to Know About Sending Us Photos

As you can imagine, we're sent lots of photos every day and we're used to working with a range of images. Because of this, we are sometimes a little guilty of taking for granted that our customers know exactly what and how to send files to us!

One of the main concerns our customers have is whether their image is of sufficient quality to make a good canvas print. The image files we receive come from many sources, including digital cameras of all types and scans, and so vary in quality enormously.

Generally the larger the image, the better the print. Most images from digital cameras are much smaller in size than the canvas print they will be made into.

Unfortunately, judging whether an image will make a good quality print at a certain size is not as simple as just checking the file size. Many factors in how the image was created and how it was subsequently saved affect the overall quality and suitability for printing...

File Type: The format in which the file is saved. Formats such as JPEG use compression, which is a method for making the file smaller and easier to send.

Compression: The greater the compression used, the lower quality the image. Some types of compression give better results than others. High compression is easily recognised as blocky "artifacts", especially at the edges of detail in the picture.

Resolution: The total area or pixel size of an image can be expressed in a number of ways. You may see images referred to in sizes such as 1280 x 1024, which is the height x length in pixels. Size can also be measured in real world units such as inches or centimetres.

DPI: Dots Per Inch is linked to the image size. It refers to how much detail is saved per square inch of image. 72dpi is the standard for images that should look good on a monitor or the web. However, a 6 x 4" image will print smaller than this at 72dpi. Therefore, the standard DPI for printing at full size is 300dpi.

Interpolation: As most photos aren't as large as the desired print size, or at 300dpi, they must be enlarged. Digital enlargement requires the computer to stretch the pixels in the image apart, and then fill in the gaps with 'guessed' pixels.

Most popular graphics software is capable of interpolation, although most give unsatisfactory results at anything other than minor enlargements. This is because of the quality of the guesswork when filling in the extra detail depends on the quality of the interpolation software.

Imagine taking a photo of a book from a foot away. The book would fill the frame and even with a modest camera, you would be able to read the pages of the book. Now imagine taking another photo of the book from 20 feet away. The book would now be a tiny part of the photo and you wouldn't be able to read the words.

A piece of software like Photoshop could stretch the blurry, tiny book so it was the same size as in the first photo. However, it would have to make an approximation of what the words should be, which wouldn't be as accurate as taking a nearer photo.

This is why we ask our customers to leave any enlargements to us, rather than use software like Photoshop to artificially enlarge the image to a bigger size. We use specialist interpolation software to obtain the optimal result possible from the original image.

To complicate these quality issues even further, many popular photo album and email programs apply their own compression to images, reducing them in size and quality for easy sending.

As a quick rule of thumb, images over 1mb in size should give a good quality print at most canvas sizes. However, for a more accurate assessment, you can always send us your image so we can let you know whether it will be work as a Photo On Canvas...