Tips ’n Tricks
What resolution do my photos need to be?
There is probably no single issue that causes more confusion or lost time for our clients than image resolution. Nothing is more frustrating than gathering photos from all over the office, region or country only to have the designer say, “Sorry, the images are too small, we can’t use them. Can you please go back and get higher resolution?” What?
Accurate’s Effective Resolution Calculator
Whether you are printing a small postcard, posting images to a website, creating a tabloid poster, or a large tradeshow exhibit, acquiring images with suitable resolution is a must.
But how do you know if you have the correct image size? You’re not a design professional with sophisticated software. How can you analyze your images to ensure they are good to go? Let’s start with some fundamentals about resolution.
- Understanding DPI: In our industry we refer to ‘DPI’ when we talk resolution or “dots per inch”. You may also hear the equally correct term “pixels per inch” PPI. So you say, “That sounds pretty simple. The more pixels per inch the bigger my photo can be used, right?” Not so fast.
- Understanding ‘effective resolution’: The effective resolution of an image is the maximum size it can be used on the end product. Just because your photo is 300 DPI doesn’t mean you can use it for a wall mural. For example, your photo may be ‘high resolution’ (300 DPI) but the maximum physical size it can be used may be only 5” x 5”. That same photo cannot be enlarged to a 10” x 10” poster because a 200% enlargement reduces its ‘effective resolution’ to 150 DPI.
How to determine effective resolution
By now you’re probably understanding that if you grab an image off your website and you hoped to use it for your trade show booth… well, you get the picture. Before you commit to an image you need to confirm if it has the effective resolution you need for your end use.
To do this, follow these three simple steps:
Step 1: Determine the final intended size of your product.
- How is your end product being published? Is it destined for a printing press? Are you creating a 5” x 7” printed post card or an 8′ x 10′ exhibit? Print images require an effective resolution of 300 DPI at final size. Exhibit or wall murals require an effective resolution of 150 DPI at full size. Photos used on the web require an effective resolution of 72 DPI at final size.
Step 2: Determine the pixel dimensions of your image.
- For MAC: Select the image. Under “FILE” select “Get Info”. A pop-up window will open. Under “more info” see “Dimensions”. The image’s pixel dimensions will be presented as pixel width x height (eg. 1200 x 800)
- For PC: Right click on the image file, look at “Properties”, and then the “Summary” tab. The image’s pixel dimensions will be presented as pixel width x height (eg. 1200 x 800)
Step 3: Test your image(s) with Accurate’ Effective Resolution Calculator.
- We’ve created a very simple tool at the top of this page that will take the guessing out of how large you can use your image files. Enter the pixel dimensions of your file and choose between the intended use of ‘Print’ or ‘Exhibit/Display’ and voila! The maximum size your image can be used is calculated for you.
- Your image cannot be enlarged beyond that size without degrading the quality.
- Any end use smaller than the calculated size will be fine.