Understanding Photo Printing Paper Sizes or What is 4XD?

What is an aspect ratio?

Every photo or movie has an attribute called an Aspect Ratio. The aspect ratio is the relation between the horizontal and vertical sizes of the photo. To calculate the aspect ratio simple divide the width or a photo by its height. For example TV in normal mode has an aspect ratio of 4:3 or in other words if we were to divide the width of the screen by its height the result would be 4/3. TV in widescreen format on the other hand has an aspect ratio of 16:9.

When we take a photo with a camera light that travels through the lenses hits a sensor (a film in traditional cameras or a CCD in digital ones). The sensor in turn translates the light into a two dimensional photo. The sensor itself has physical attributes such as width, height, granularity (in films) and number of pixels (in digital CCD sensors).

The connection between an aspect ratio and photo printing

When photos are printed on paper the aspect ratio of the paper must be the same as the aspect ratio of the sensor that was used to take the photo. If the aspect ratios are different the result will be a blank area left on the paper or a stretched photo that fits the paper but distorts the objects in it.

Why does it happen? The answer is pretty simple. For the sake of explanation lets assume a photo sensor that is 6 inches wide and 4 inches high (real sensors are much smaller). Lets assume that we are trying to print the a photo taken with that sensor on a paper that is 4 inches high. If the paper width would be less than 6 inches we will have to crop part of the photo since there won’t be enough space available on the paper. If the paper width is more than 6 inches we will have to leave a blank area on the paper since we do not have “enough photo” to print on more than 6 inches. If we want our photo to exactly fit the page we can stretch or shrink the photo horizontally to whatever the paper size is – but then the objects in the print will be distorted and look more fat or thin as they were in real life.

Printing on a 4X6 paper

One of the most common paper sizes is 4X6. This size was used for many years for printing photos taken with traditional film cameras. The traditional film had an aspect ratio of 3:2 and thus the photos taken with a traditional film camera would fit perfectly on a 4X6 papers.

For reasons beyond the scope of this article digital cameras use sensors with a different aspect ratio than tradition film cameras. The following table summarizes popular image sizes in pixels and the respective aspect ratio (sensor pixels, width X height and aspect ratio):


2 MP – 1600 X 1200 – aspect ratio 4:3

3 MP – 2048 X 1536 – aspect ratio 4:3

4 MP – 2272 X 1704 – aspect ratio 4:3

5 MP – 2592 X 1944 – aspect ratio 4:3

6 MP – 2816 X 2112 – aspect ratio 4:3

8 MP – 3200 X 2400 – aspect ratio 4:3

As can be seen digital sensors, regardless of the number of pixels they support have a 4:3 aspect ratio.

So what happens when we try to fit a digital photo on a 4X6 paper? The photo just doesn’t fit! it is either too wide or too high. For example if we want to print on the full 4 inches height we will only fill 51/3 inches (4X51/3 is a 4:3 aspect ratio) and 2/3 inches will be left blank.

To solve this problem and use the full paper size many printing services allow the user to crop a part of the photo. The assumption is that instead of leaving a blank area on the print the user would prefer to cut a part of the photo that is not important and use the whole paper for the rest. Some services allow the users to choose a preference for either cropping the photo or leaving a blank area on the print and this preference is automatically applied to all his prints.

What is a 4XD paper?

In light of the popularity of digital cameras and digital prints many printing services are introducing paper sizes that are designed for digital prints. This means that the aspect ratio of the paper they offer is 4:3 and thus photos taken with digital cameras perfectly fit the paper.

The new digital compatible paper sizes have an aspect ratio of 4:3 (the digital sensor aspect ratio) and are as close as possible to their traditional film paper sizes. So – in the digital world a 4X6 paper size will actually become a 4X5 1/3 (a 4:3 aspect ratio paper size that is as close as possible to a 4X6 size).

As a marketing gimmick and instead of writing exact paper sizes many use the “digital” abbreviation of 4XD – which means 4XDigital or in other words “as close as we could make it to 4X6 that is digital camera aspect ratio compatible”.

As digital cameras become more and more popular it is expected that more papers sizes which are digital camera compatible will be introduced. In a few years from now most printing services will support the digital paper size by default and the film compatible one will be the exception.

Turn Your Old Photo Paper Prints into Modern Digital Format Albums

Although digital cameras have been around for a few years and are becoming more and more popular many of us still have a large number of older film camera paper prints, slides and negatives. Most people keep their paper prints and negatives at their homes and only use digital formats for new photos they shoot with their new digital cameras. In this article we will discuss converting your old paper prints into digital format.

Photos are usually kept at home in one of three formats:

Paper prints: the most common format, usually at sizes like 4X6 and 5X7. Over time paper prints tend to lose their quality. Depending on how well they are kept the paper might turn yellow and bend and the colors might fade.

Negatives: also known simply as film. This is the processed film usually 35mm from which the prints where made. Although negatives can get damaged over time they are more likely to maintain their high quality. Negatives are hardly used unless new paper prints are needed.

Slides: very similar to negatives used for projecting photos on a large screen.

There are many advantages to digital photography. Having your photo album in digital format allows you to easily print paper copies either at home or using a printing service, to view your photos on your computer, to share photos with friends and family and maybe most importantly to practically archive your photos for eternity. So if digital format is that good why not convert all those old photos from traditional paper and negatives to digital? Here is how:

There are different considerations when converting from paper to digital. Professional photographers spend a lot of time and money on this process. For most amateurs and consumers very simple methods can be used which are both cheap and easy. Scanning paper prints and negatives requires different equipment and considerations. For most home users scanning the negatives is not necessary.

Scanning paper photos prints

Photo paper prints are easy to scan. You can choose to scan them yourself at home (purchasing a scanner that can do the job is usually cheap and costs less than a $100). You can also choose to mail them (or hand them) to a professional scanning service that will scan them for you and mail you back the originals and a DVD with the digital scans (such services include www.digmypics.com, www.digitalpickle.com, www.britepix.com and many more)

There are pros and cons to scanning at home or using a professional service. If you have a small number of photos scanning at home is easier. If you have plenty of photos using a service might be easier but you can end up spending more money. In addition mailing your one and only hardcopy of your photos is a risk since they might get lost.

If you are going to scan at home consider the following:

Resolution: the resolution of a scan is measured by the number of dots per inch that the scanner can produce. Most scanners can scan at 1200 DPI or more. Usually the scanner can be set to scan at different resolutions. The higher the resolution the slower the scan and the bigger the photo file size will be. For most paper prints scanning at 300 to 600 DPI is enough but you can experiment scanning at higher resolutions if you feel it provides better results.

Speed: If you have a small number of photos speed is not an issue. If you have hundreds or more of photos scanning speed becomes important. To get fast scans you would have to scan at the lowest resolution possible that results in good enough scans – for most paper prints 300 to 600 DPI is enough.. Also if you’re going to buy a scanner check the scanning speed (usually measured in the number of scans per minute make sure that you check the speed at the DPI you’re going to use).

Photo feeding: if you only have a small number of photos this is not an issue. If you have many photos make sure that the scanner you buy allows fast and easy loading of photos. Some higher-end scanners will let you load a stack of photos and will automatically feed and scan them for you. These scanners are the right choice if you are planning on scanning hundreds or more photos.

Scanning negatives and slides

Scanning negatives and slides is harder than scanning paper prints. In most cases it is easier and maybe cheaper to use a professional scanning service (such services include www.slidescanning.com, www.myspecialphotos.com, www.pixmonix.com and many more). If you want to scan at home your standard flat scanner will not be good enough. In most cases you will need to spend money on purchasing a film/slides scanner. Those scanners are more expensive than the flat paper scanners. Negatives and slides are small high resolution sources and thus require scanning at higher DPI than paper prints. In most cases 2400DPI or higher should be used.

The considerations for scanning negatives and slides are similar to scanning paper prints. If you need to scan just a few negatives or slides speed and ease are not important but if you’re going to scan hundreds or more you should spend more money on scanners that can feed the negatives or slides automatically or can just load a roll of film and scan it.

The good news is that in most cases scanning negatives is not needed at all. For most amateurs and consumers scanning home photo paper prints is more than enough and scanning the source negatives is a not needed. It is recommended of course to keep the negatives in a safe place. You can use the digital scans for future prints or just for viewing on your computer screen and sharing with your friends and family.

In conclusion scanning your photo paper prints is easy. You can do it yourself at home or you can use a professional scanning service. You can convert all your memories into digital format with a small investment and make sure that you can enjoy those photos and also keep them in their original quality for eternity.