44. PRINT RESOLUTION

IN LESSON 42 I mentioned that the Dimensions checkbox in the Guides panel can provide some helpful information (Figure 44.1). This is where it’s going to come in handy.

Let’s say we have an image ready to print on a 17 × 22-inch sheet of paper, and it looks like the overall cell size is about 20 × 11 inches. But we need to know the resolution of the image that we’re working with (Figure 44.2).

If you look at it from a general point of view, most images print the sharpest at about 240 pixels per inch, or 240 ppi. In the Print Job panel you will see a Print Resolution checkbox with 240 ppi written next to it. This up-samples any image with a resolution lower than 240 pixels per inch to get it to a target resolution of 240 ppi. However, we need to know the original resolution of the image in order to judge whether this will give us a good print.

Make sure you’ve selected the Dimensions checkbox in the Guides panel so that you see the image dimensions at the top of the cell. Now when you uncheck the Print Resolution checkbox, you will see the resolution of the image next to the dimensions. In Figure 44.3, you can see that our example image is 20 × 11 inches at 368 pixels per inch—this file is huge. There is more information in the file than I need to get a good print of the image. In fact, I could probably print this file much larger and still get a really sharp image because the resolution is so high.

Figure 44.1 Make sure you put a check in the Dimensions checkbox.

Figure 44.2 Checking the print resolution on a file.

Figure 44.3 Uncheck the Print Resolution checkbox to see the original resolution of an image file.

In Figure 44.4, I have a low-resolution JPG of Dancing House. Notice that I’ve unchecked the Print Resolution checkbox, and Lightroom is telling me that if I were to print this image at 19 × 13 inches, my resolution would only be 76 ppi. That’s not good at all. But I wouldn’t know this information if I had that Print Resolution checkbox checked. The ppi would not be shown next to the dimensions and I’d have to be okay with Lightroom taking the image from 76 pixels per inch all the way up to 240.

This doesn’t necessarily mean that the print is going to be bad, but you do need to consider whether or not you want to print with that much of a resolution jump. Any time you let Lightroom upsample your image, the software makes a prediction of what the missing pixels would look like based on the pixels that are there. I’m completely comfortable with making a jump from something like 180 ppi to the 240 ppi range. Lightroom’s upsampling technology is pretty good at getting to a final print dimension that doesn’t look to bad. But I begrudgingly make that concession. If I see numbers that are under 100 ppi, I’ll always opt for a smaller print. I equate this to jumping from one rock to another across a pond. The closer those rocks are to one another, the more comfortable I am in making the jump.

Figure 44.4 At approximately 19 × 13 inches, the resolution of this image is only 76 ppi.

If you lower the dimensions of the image, you will notice that the resolution will increase. In my example, the maximum resolution I could get for this picture would be in the 250 ppi range, and that would require me to resize my image to about 6 × 4 inches (Figure 44.5). So that’s about as big as I can go. In this case, I would probably choose a different paper size and print the image with a really big matte.

When you’re planning to print an image, you need to know how much information you have to work with so that you can make a decision as to how big your print can actually be. Checking the Dimensions checkbox and unchecking that Print Resolution box will give you the information you need.

Figure 44.5 I would need to resize my image to about 6 × 4 inches to get a high enough resolution for a good print.