What are the sizes of photographs for printing? Standard sizes

In this article, we'll look at how image resolution affects print quality.

Have you ever downloaded a picture from the Internet and then when you printed it, got results that were, well, smaller than you expected? The image looked great on your computer screen, but when you printed it, it either printed at postage stamp size or normal size but looked blurry or "blocky"? The reason is the image resolution.

In fact, this is not entirely fair. It's not that the image resolution is specifically set in such a way as to make you unhappy when you print a photo from the Internet. The problem is that most photos on the Internet are very small pixel sizes, typically around 640 pixels wide by 480 pixels high. Or even less.

Because the image doesn't have to be very large to look good on a computer screen. And also because small images load much faster than larger ones ( this is a completely different question that we will not touch on in this article).

So what can we do to make photos downloaded from the Internet look like high-quality digital camera photos when printed? The answer is absolutely nothing. In most cases, online photos simply don't have enough pixels to print at high quality. At least if you don't print them in postage stamp format. Let's find out why.

First of all, let's move a little away from the topic of downloading images from the Internet, as such, and the fact that we really shouldn't do it anyway without the permission of the copyright owner. Let's look at image resolution in general.
The term " image resolution" means how many pixels of your photo will fit on each inch of paper when printed.

Obviously, since your photo has a fixed number of pixels, the more pixels there are in one inch, the smaller the image will appear on paper. Likewise, the fewer pixels per inch you print, the larger the image.

The number of pixels per inch when printing is called " image resolution". Image resolution determines the print quality of the image. It has nothing to do with how the image is displayed on a computer screen. That's why photos downloaded from the Internet tend to be much higher quality on screen than when you print them.

Let's take a photo as an example:

Not a very good photo of a horse

I can't help but laugh every time I see this photo of a horse that I took while driving through the countryside. Normally this horse is a proud, powerful, dignified animal, but I seem to have caught him in a rather unsightly position. She's standing at a slightly odd angle, straw hanging from her mane, and I think I caught her chewing her food.

Either that or she's desperately trying to smile at me. In any case, this horse is already embarrassed that I caught him at such a moment. Let's use this image as an example.

First, let's see what Photoshop can tell us about the current size of this photo. I go to the "Image" menu at the top of the screen and select " Image Size", after which a dialog box appears with the corresponding name " Image Size«:

The Image Size dialog box shows us the current photo size

Dialog box " Image Size"is divided into two main parts: " Dimensions in pixels"at the top and " Document Size"directly below it.

« Dimensions in pixels" indicate how many pixels our image contains. " Document Size” tells us how large the image will appear on paper if we print it. If we look at the section " Dimensions in pixels", then we see that this photo has a width of 1200 pixels and a height of 800 pixels. This may seem like a huge number of pixels ( 1200 by 800 = 960000 pixels!).

And this, of course, would be the case if we were displaying an image on a computer screen. In fact, at 1200 by 800, it may be too large an image to fit entirely on your monitor!

But just because it looks nice and big on screen doesn't mean it will be nice and big on print. At least not with a high degree of quality. Let's take a closer look at what the section " Document Size»:

The Document Size section tells you how large or small the photo will be when printed at a certain resolution.

Chapter " Document Size» dialog box « Image Size" allows us to know two things: what the current resolution of our image is and how big or small the image will be if we print it based on that resolution.

We currently have our resolution set to 72 pixels/inch, which means that out of the 1200 pixels that make up the right to left edge of the photo (the width), there will be 72 pixels for every inch of paper. And of the 800 pixels that make up the image size from top to bottom (height), there will also be 72 pixels for every inch of paper.

The value in the Resolution field is determined for the width and height, not the total number of pixels. In other words, for every square inch of paper, there will be 72 pixels per inch of height and width. The total number of pixels printed in each square inch of paper would then be 72 by 72 ( 72 pixels in width and 72 pixels in height). Which gives us 5184 pixels!

Let's do some simple math to make sure that the width and height shown to us in the " Document Size"is correct. We know from the section " Size in pixels"that we have 1200 pixels from left to right and 800 pixels from top to bottom. Print resolution is currently set to 72 pixels/inch.

To figure out how big our image will be when printed, we just need to divide the number of pixels from left to right by 72, which will give us our image width when printed. And also divide the number of pixels from top to bottom by 72, which will give us the height when printing. Let's do this:

1200 pixels wide divided by 72 pixels per inch = 16.667 inches wide
800 pixels divided by 72 pixels per inch = 11.111 inches in height

Based on our own simple calculations, at a resolution of 72 pixels/inch (ppi for short), our image would be 16.667 inches wide by 11.111 inches tall when printed. And if we look at the section " Document Size"once again:

Confirm print sizes in the Document Size section

This is exactly what is stated here! Wow, a 1200 by 800 pixel photo is large enough to print at 11 by 14 inches, we can even make it smaller a bit! Amazing!

Unfortunately no. If only everything in life were so simple.

The fact is that 72 pixels per inch is not enough to give us a sharp, good quality, professional looking image. Not even close. To give you an idea of ​​what I mean, here's a rough approximation of what the photo would look like on paper if we tried to print it at 72 pixels per inch.

You'll have to use your imagination a little. Try to imagine it's 11 by 16 inches:

What will a photo look like on paper when printed at a resolution of only 72 pixels per inch?

Doesn't look too good, does it? The problem is that 72 pixels per inch provides too little information about the image to print a sharp, clear photo on paper. It's like not enough peanut butter has been spread on a large piece of toast. The photo now looks blurry, boring and generally unattractive.

We don't see this on a computer screen because computer monitors are generally referred to as low-resolution devices. Even a photo with relatively small pixel dimensions, such as 640 by 480, will look great on a computer screen.

Printers, however, are high-resolution devices, and if you want your photos to print clearly and show everything small details, you need a resolution much higher than 72 pixels per inch.

So what is the maximum resolution you need for professional quality printing? It is generally accepted that this is 300 pixels per inch. Printing an image at 300 pixels per inch compresses the pixels enough to maintain sharpness.

In fact, 300 is usually a little more than you need. You can often see photos at 240 dpi resolution without any noticeable loss in image quality. However, the professional standard is 300 pixels per inch.

Let's take the same image, with the same 1200 pixels width and 800 pixels height, and then change the resolution from 72 pixels per inch to 300 pixels per inch, and see what happens.

Here is the dialog box " Image Size» with a new resolution of 300 pixels per inch. Please note that in the section " Size in pixels"at the top we still have 1200 pixels in width and 800 pixels in height.

The only thing that has changed is our resolution - from 72 to 300:

Print resolution has been changed to 300 pixels per inch

The fact that the resolution has increased from 72 to 300 pixels per inch means that of the 1200 pixels that our image is wide, 300 pixels are printed on one inch of paper. And out of 800 pixels of height, 300 are printed for every inch of height of paper. Naturally, with so many pixels per inch of paper, the printed photo will be much smaller.

And of course, the Document Size section now says that our photo will print at just 4 inches wide by 2.667 inches tall:

The photo will now be printed in a much smaller size than before

Where did these new width and height values ​​come from? Again, some simple math:

1200 pixels wide divided by 300 pixels per inch = 4 inches
800 pixels high divided by 300 pixels per inch = 2.667 inches

The photo will now be printed at a much smaller size than it was at 72 dpi. But what we lose in physical size we more than make up for in image quality. At 300 pixels per inch ( or even at 240 pixels per inch) we will enjoy clear, professional quality results:

Higher print resolution results in smaller photo sizes, but the image quality is much higher.

Of course, most people don't print their photos in custom formats like 4 by 2,667. So how do we make sure we get professional quality results when printing in a more standard format like 4 by 6? Great question, and we can get the answer by turning to boring arithmetic again.

Let's say you took photos from your recent family vacation, taken with a digital camera, and you want to print some of them on a 4 by 6 printer. Now we know that in order to achieve professional quality photos, we must set the resolution images at a minimum of 240 pixels per inch. Although the official standard is 300 pixels per inch.

Let's look at both of these resolutions to see how large the camera images need to be in order to print them out in good quality at 4 by 6. First, let's look at 240 pixels per inch.

To figure out how large in pixels our images need to be for them to print at 4 by 6 in professional quality, we just need to multiply 240 by 4 for the width, and then 240 by 6 for the height ( or vice versa, depending on whether your photos are in landscape or portrait orientation).

Let's do this:

240 pixels per inch x 4 inches wide = 960 pixels
240 pixels per inch x 6 inches high = 1440 pixels

Based on these calculations, we see that in order to print a digital photo in 4 by 6 format at 240 pixels per inch and still maintain excellent quality, the pixel size of the photo must be at least 960 by 1440. We see also how many pixels should a photo have overall, 960 times 1440 gives us 1382400 pixels.

Let's round this value to 1,400,000 pixels. This may seem like a large number, but in fact it is. 1.4 million is the minimum number of pixels needed to print a 4 by 6 photo at the minimum normal quality resolution of 240 pixels per inch.

The good news is that most digital cameras on the market today are 5 MP (“ mega pixels" or "millions of pixels") and higher. So you won't have any problem getting good quality 4 x 6 prints even at 300 ppi.

Of course, we haven't yet calculated exactly how many pixels we need to have to print a professional-quality 4 by 6 photo at 300 pixels per inch. So let's do it. We will use the same simple formula that was described above.

We are often asked: - “Can you print A4 photos?”

Of course, we can print photos in almost any size, but this issue requires clarification.

Photo paper formats differ from international ISO formats, but most often in everyday life we ​​operate with terms and sizes that are familiar to us, such as A4, Whatman paper, etc. Although photo paper and regular paper formats are quite similar, they are still different from each other.

Major photo formats have aspect ratios similar to those of modern digital cameras, 1:1.5 (2/3) or 1:1.33 (3/4). Standard international paper sizes have an aspect ratio of 1:1.4142, meaning they are not the same proportions. When printing on Noritsu minilabs, photo standards are used. The familiar photo frames and photo albums for storing photographs also meet photo standards.

This table shows the ratio of the photo formats we print to standard paper.

Now let's look at each of the photo formats in detail. The popular 10x15 format is 2 mm smaller on one side than standard A6, and 5 mm larger on the other. Therefore, if you need A6, you should order a 15x21 photo and trim off the excess manually.

Below you see how the 10x15 format compares with the well-known A4.

A 15x21 photo will be slightly larger than an A5 sheet. On one side by 5 mm, on the other by 1 mm. Therefore, if you need A5, feel free to order a 15x21 photo, you will cut off the excess.

Below you see the ratio of 15x21 to A4.

The 20x30 format is almost A4, but the photo is 6 mm smaller on one side and 9 mm larger on the other than A4. 20x30 and A4 are disproportionate.

Below is the ratio of a 20x30 photo to A4.

If you need A3, then choose a 30x40 photo. 30x40 is 9 mm on one side and 1 mm on the other more than A3. Feel free to order and cut it yourself =).

Below you see the ratio of 30x40 and A3.

Photo 30x45 is larger than A3. This can be seen in the picture below.

A 30x60 photo is difficult to compare with regular paper. 30x60 is significantly smaller than A2 (whatman paper) and significantly larger than A3. But this does not prevent 30x60 images from being popular among photographers.

Below you see the ratio of a 30x60 photo to A3.

Below is the relationship between photo formats.

Hello!!!
In the 20th century, photographers had no questions about the format of the image being created. Back then it was possible to develop a photograph of any size. Now there are several formats that are most popular. This is explained by the prevalence of standard photo albums; in them, photographs of a non-standard format do not look very attractive.
What are the sizes of digital photos?

An ordinary photograph printed on photo paper has only physical dimensions. Digital photography has many more different properties. Theoretically, you can print almost any image. But if this process occurs at a pixel density of less than 300 dpi, then some artifacts will appear on the printed photo. Therefore, there are some restrictions, which will be discussed below.
Photo sizes in pixels

The most important parameter is the size (resolution) of the digital image. Computer programs display photo sizes in pixels. To print a standard photo, you need a resolution of at least 1795 x 1205 pixels. Any digital camera can now take a picture of this size. Even in mobile phones, it is very rare to find cameras that cannot save photos in this resolution.
Photo dimensions in cm (centimeters)

Aspect Ratio
An equally important parameter is the aspect ratio. This property shows how much longer one side is than the other. The standard aspect ratio is 3:2. Most matrices installed in modern cameras have the same parameter. Sometimes other ratios are provided in the camera menu. When you select them, a banal cropping of the edges of the image occurs. In this case, the resolution is reduced to one or another value.
Often photographers choose an aspect ratio of 16:9. It's called widescreen. Now many monitors and TVs have the same parameter. On them, such pictures are displayed in full screen. But the sizes of photographs for printing also change. The width of the printed image must be increased. When choosing a standard print format, you will have to crop off a fairly decent part of the image.
Photo paper

The emergence of new standards is dictated by photo paper manufacturers. No photo lab will print an unusually sized photo for free, as this will require cutting. finished photo. And this already applies to additional services.

Small photo sizes

Let's get acquainted with some terms that are used in the world of digital photography.

Linear photo size is the width and height of the printed photograph in millimeters. The linear size of a photograph can be obtained by measuring it with a regular ruler. For example, the linear size of a 9x13 photograph is 89x127 mm.

Pixels- these are the points that make up the image. Just as a mosaic is made up of pieces, a digital photograph is made up of pixels. The more pixels, the finer details you can see in the image.

Size in pixels is the width and height in pixels of a digital image. For example, digital cameras take pictures of standard sizes 640x480, 1600x1200, etc., and the number of pixels displayed on a computer monitor is 800x600, 1024x768, 1280x1024.

Permission is a number that relates the size of the image in pixels and the linear dimensions of the print. It is measured in the number of pixels (dots) per inch (1 inch = 25.4 mm) - dpi (dots per inch). The recommended resolution for printing high-quality photographs is 300 dpi. Practice shows that the minimum acceptable resolution for printing photographs is 150 dpi.

In most cases, you print photos of standard format 9x13, 10x15, 13x18, 15x20, etc. Each format corresponds to strictly defined linear dimensions. For each format, you can calculate the recommended dimensions of the original image in pixels so that the resulting print has a resolution of 300 dpi or more.

For example, the linear dimensions of the 9x13 format are 89x127 mm. Multiply the height of the photo (87 mm) by the resolution (300 dpi) and divide by the number of millimeters in one inch (25.4 mm), the result will be the number of pixels of the original image in height

89*300/25.4=1027 pixels.

Same for width

127*300/25.4=1500 pixels.

Thus, for any image whose size is larger than 1027x1500 pixels, when printed on a 9x13 format, the resolution will be greater than 300 dpi. In practice, it often happens that a photograph with a resolution of 150 dpi looks no worse than the exact same one, but with a resolution of 300 dpi, it depends on what is shown in the photograph and from what distance it will be viewed.

When placing an order online, the system automatically determines which formats are recommended for printing the uploaded photo. If you have chosen a format other than the recommended one, then a corresponding message is issued, and The administration is not responsible for the low quality of the printed photograph.

Table of standard formats and corresponding linear dimensions.

- inkjet or less commonly laser. We also all know that there are certain popular photo sizes. But what are the standard photo sizes for printing? Let's put them in a table in which we list all the sizes of photographs for printing.

Quite often, when we decide to print our photographs, we encounter a problem and ask ourselves: what size should they be? Of course, most modern digital cameras automatically select the required photo resolution, but it also happens that you need to print photos downloaded from the Internet or captured on your phone, what to do in this case?

First, let's answer the question - why should you know (and accordingly adhere to) standard photo sizes for printing? The point is that having come up with standard photo sizes, photographic paper began to be made in the same size. Therefore, the correct ratio of height and width of the photograph is very important. Otherwise, the photos will end up stretched both in height and width. The resolution of the image is also important - it affects the quality (sharpness) of the image when printed.

The sizes of photographs for printing are shown in the table

Where there is a standard or format, this is the aspect ratio that it is advisable to adhere to so that you do not have to crop or stretch the photo. The second column contains the photo sizes in centimeters, the third in pixels, I think this is understandable.

Standard sizes The photos have dimensions of 10.2 x 15.2 cm (highlighted in the table) - these are the usual album photos that we are used to seeing.

What to do if the photo has different dimensions?

Let's say you compared the sizes of photographs for printing, the table of which was presented above, and found out that your photo has different sizes, what should you do in this case? If the aspect ratio is different, then simply increasing or decreasing the centimeters will not do. You will have to crop the image to the desired format.

How to quickly crop a photo to the desired size?

There are two main ways.

The first way is to use the simplest image editing program. Almost all versions operating system Windows yes Paint program in the "Standard Programs" tab. Having opened a photo file in this program, you need to drag the border of the picture on the right or bottom and thus crop the photo to the desired size in pixels. The image size in pixels is shown at the bottom of the program window.

The second way is to use specialized image editing programs. Most often used Photoshop program- she is the most popular and the most professional. I note that we need to precisely adjust the photo to the desired format (depending on the version of the program, the location of this button may change - just squeak it on the toolbar).