One of the biggest challenges for photographers preparing their images for printing. Not only do you need to think about color profiles, ratios, and file format, but you also need to think about enlarging photos.
When it comes to enlarging photos for printing, we need to make sure the image retains its high resolution. In this article, we give you the top tips on how to do it correctly.
Why Would You Want to Enlarge Your Image?
There are a number of reasons why you would want to enlarge your image. One of the main reasons is that you want to create a really big print from one of your photographs.
These are perfect as presents or even placed on your own home walls. You might even think of having a portfolio of work, where the images might need to be bigger than their initial resolution.
The other main reason for enlarging photos is working with low-quality images. You may have captured digital photographs at a time when the resolution wasn’t at its best.
But how to create a larger print without losing quality?
How to Get the Best From Your Images Every Time
In photography, we follow the basic rule of Crap In, Crap Out (CICO). Basically, this means, if your images aren’t up to scratch, you aren’t going to be able to get much out of them.
But, you can take an OK image and make it into something better. Here’s how to ensure you always get the best results.
Shoot Using Largest Size possible is probably the best advice anyone can give you. For all those who like to complain about raw vs jpegs, yes you can take a fantastic image with the jpeg format, it’s just more difficult.
By shooting in raw, you give yourself the change to adjust your image. Raw images give you up to six stops of exposure play when editing your image. This will depend on the scene you are photographing.
If you are going to shoot in jpeg, ensure it is set at the highest quality setting.
Another great tip is to photograph as best you can. What I mean here is use equipment and settings that will ensure a high-quality image. A tripod is essential for long exposures, for example.
A low ISO will eliminate any grain or digital noise. Consider using a remote shutter release, or applying the ‘mirror lockup’ setting in your camera’s settings. These will help to keep camera shake to a minimum.
If you aren’t photographing images using digital cameras, then you might be scanning in negatives. My advice here is to ensure you scan images well. I know it seems very obvious, but you might be scanning your images in a lower quality.
Scan at a high resolution to ensure for correct re-sampling of your negatives. Ensure your scanner and scanning software are up to the task. To help, we have a few articles to ensure you are on the right track.
For one, How to Find the Best Film Scanner for Photography is a great place to start. Next, read our Vuescan Review: Is it Really the Best Film Scanning Software?
This will give you an idea of what to expect.
7. Force Image Resolution / Re-Sampling
After digging around in your image folders, you come across a digital image from a few years back. The photo you find has the makings of a great image. Composition, color management, and even the subject are all interesting.
Yet, the resolution is only 250 pixels wide, its longest edge. You want to turn it into large prints, so we have to enlarge it.
If we change the size from 250 pixels to 650 pixels, the image gets bigger. But, the image quality drops substantially, and now the image is pixelated. What can we do about this?
The idea of re-sampling an image is better when used in small increments. Instead of jumping from 250 pixels to 650 (almost 150%), we want to do this in 10% stages.
We start with 250 pixels, then 275 pixels, then 325 pixels, up to 450 pixels. Here, you will probably start to see some pixelation.
This process helps to keep the resolution and image quality as high as possible. We do this while enlarging the image to emphasize the main focus of the image.
To do this, you need to ensure you have re-sampling enabled in your photo editing software. I recommend Pixelmator or Adobe Photoshop.
For more information on megapixels, you should read our article on the Best Resolution to Print From.
6. Increasing the Resolution
Megapixels are directly responsible for the good quality of your image. The more megapixels your camera’s sensor has, the better the quality and the bigger the prints.
Generally speaking, the rule for the printing size of your digital photos can be found using a simple equation. First, you need to know how many megapixels your sensor has, or the size of your image’s pixels.
Majority of the time, I use my Canon 7D. Its sensor has a megapixel rating of 18. The images it produces are 5184 x 3456 pixels. When I multiply these numbers together, I get 17,915,904. rounded up, this is the size of my sensor.
Second, by dividing the width of the image in pixels by 300, you get the highest quality print size in inches. 5184 x 3456 gives us an image size of 17.28 x 11.52 inches.
But, the image needs to have a resolution of 300 DPI (dots per inch). Anything less than this will result in less than the highest quality, ranging from good, all the way to terrible.
The quickest way to make sure your photograph is set at 300 DPI is by using an image editor. I use Adobe Photoshop for all resolution changes.
Go to Image>Image Size. You can change the resolution in the open dialog box. When you change this, the size of the image will also change, so take this into account.
You can use any software that lets you change the DPI size, not just Photoshop.
5. Avoid Lossy Formats like JPEG
It is always best to talk to your printing house beforehand. They will give you the most up to date information on printing your images in the highest quality possible.
Also, they will tell you the range of DPI you can use, the image’s largest size, and what color profile they can print with. They might even have one that works best with their printers.
The printing house will also tell you what file formats they can print from.
When it comes to file formats, you might only know jpeg. The problem with these is they are ‘lossy’ formats. This means, saving in these formats attempts to take information away from the photo.
You can’t improve the quality or resolution with a jpeg. When you save a jpeg at its highest quality/lowest compression, information from the brightest areas are dropped.
This happens every time you reopen and save the jpeg image. This is why shooting in raw has very obvious benefits.
Jpeg compression works by examining pixel brightness. That pixel is assigned a ‘score’ from the scale of -1024 to +1024. It is important to know this is only based on brightness, not color.
Many people feel that jpegs are great for printing because they look great on the web. The problem with that is, jpegs look good online because they were developed for this use.
Here, there are considerable file size considerations. Each website would take hours to download if the images were not compressed. You really need to be using Tiff or even PDF to retain as much information (resolution) as possible.
These file formats are much less lossy.
4. Increase Your Computer’s Memory for Faster Editing
One thing that could help the resolution of your image is hardware based. This is one area that many photographers overlook when it comes to photo enlargement.
Unlike other computer operations, photo enlargement is extremely memory consuming. This is down to the program running the image, the program used to enlarge and the completed, enlarged image.
All this happens in the memory at the same time. This is especially draining when using raw images, converting to a non-lossy format and using a large program such as Photoshop.
Luckily, computer memory is relatively inexpensive. You may find you’ll be able to do the above while listening to music after a few bytes of RAM.
3. Sharpen Your Image
Another way to make your image better for enlarging is to sharpen it. There are a few sharpening procedures you can use across your images to bring out their quality.
One way to do this is to use an ‘unsharp mask’. Most editing software have this feature. Basically (and it isn’t a basic tool to use) you need to copy your image and make the second version blurrier than the first.
These are then blended back together and it produces a faint ghost of the first image. A mask or filter over the original image makes it sharper.
Your raw processor might have automatically softened your images during import, or your DSLR camera settings were a little short of perfect.
Apart from the Unsharp Mask, you can use the High Pass Filter method, or Rough Edges – all available in Adobe Photoshop.
2. How to Resize Your Image to Avoid Quality Loss
Not all images are the size that we want them to be. We will need to resize them at some point, and it is important to know exactly how resizing actually works.
When we resize an image, we change its pixel information. If the image is reduced in size, information is also reduced. When an image is enlarged, the photo editing software must create and add new information.
It does this to achieve a larger size. This is only completed using the software’s best guess. A larger size results in a very pixelated, soft or blurry image.
When it comes to photo printing, say, an 11×14″ image, it isn’t necessary to resize the image to that exact size. The DPI amount and the ratio of the image are what’s important.
If you are aiming to fill an 11×14″ frame with an image that has a 2:3 ratio, the print will need to be printed at 12×18 and then cropped. Here, you lose 4″ of the image from the sides and another 1″ from the top.
As long as you have a DPI of over 250, you can print an 11×14″ from that same ratio (1.57:2).
1. Use Dedicated Photo Software for Image Enlargement
You might feel that programs like Adobe Photoshop or Capture One are overkill when it comes to enlarging photos. These photo editors have a lot of bells and whistles, but if you only need one, they are expensive.
Instead, there are a number of apps out there dedicated to enlarging photos. They do so without loss of quality and are easy to download and use. A Sharper Scaling claims to be superior to Photoshop.
This program works with Windows. There isn’t a dedicated software for mac, but Waifu2x offers a strong option. There is also the simple Image Enlarger. I also heard good things about Let’s Enhance.
Basically, as these programs have one job, they do it well. They ‘guess’ much better than other programs, and create sharper images when resized.
You have to give them a try to find out which one works best for you.
Enlarging your images might be necessary at some point. Either you decide to sell your prints online as part of your business model, or you want to give them to people as gifts. Even hanging them in your own home.
There isn’t one magical ‘fix all’ system. I use many of the above tips together.
I might enlarge photos using image editing software, and then, I’ll check to see if it needs sharpening. If I’m not printing at home, I’ll contact the printing lab to see what they need from my print.
This is the best way for my work to get printed. It is different with each image. Use these tips above and don’t be wary if you need to use more than one or two.
After all, you want to have the best possible print, right?