Martin Evening
  • Marrutt Evening

Resolution Comments - Martin Evening

Hi John,

Firstly, thank you for contacting me. I have purchased supplies from Marrutt in the past and always appreciated the service offered.

What I would say is that over the years the advice has had to change to keep pace with the associated changes in technology. For example, 20 years ago inkjet printers were just beginning to be taken seriously for photographic print output. Back then the advice was to ensure the print resolution was a number that divided into the print head resolution. i.e. if printing at 2880, choose a resolution such as 480, 360 or 288.

The method I use now is based on advice I got from Jeff Schewe. This is regards printing via Lightroom, which is my preferred method. Here is what I have written in my Lightroom book:

"Lightroom automatically resizes the image data to the print size you have set in the Layout panel. Providing the print output image ends up falling within the range of 180 to 1440 ppi, there is no real need to use the Print Resolution option to interpolate the print data. Basically, Lightroom automatically applies the correct amount of sharpening on a sliding scale between 180 and 1440 ppi and it is best to let Lightroom work out the optimum pixel resolution and sharpening.

With some prints though, it may help to manually increase the resolution. If you are making blow-up prints that contain high-frequency edge detail, it is worth checking the Dimensions info box. This can be done by enabling ‘Dimensions’ in the Print module Guides panel. If the output resolution appears to fall significantly below 360 ppi, and especially if making smaller prints, it may be worth using the Print Resolution box in the Print Job panel to manually set the file’s resolution to 50% more than whatever the native resolution happens to be. When you do this, Lightroom applies an adaptive upsampling routine that combines the Bicubic and Bicubic Smoother interpolation algorithms prior to applying the print output sharpening.”

This advice confirms your observations that when making smaller size prints it can be beneficial to print at higher print resolutions. More specifically, it is more beneficial if the subject matter has fine detail. There isn’t much point if the subject contains low-frequency edge detail. But note that the advice from Adobe is to just allow your print to print at as high a resolution as it allows (up to 1440 ppi).

In practice, I have been recently making A2 and A1 size prints for an exhibition and been very pleased with the sharpness and detail of the final prints. This is probably down to the fact that the source landscape image files are mostly around 40 MP or bigger in some cases. There is therefore ample resolution for me to print with. But it is also mostly due to the use of output sharpening. What is great about Lightroom’s print module is that you simply check to add print output sharpening, choose between matte or glossy and Lightroom calculates the rest for you, targeted to the precise pixel output resolution, whatever that might be. Now, I should disclose that I was personally involved with Pixel Genius that created the sharpening routines that we licensed to Adobe. However, the original PhotoKit Sharpener plug-in has now ceased offering support and can be downloaded for free. Which means those people who prefer to print via Photoshop or a RIP can get the Sharpener plug-in for free to apply essentially the same type of sharpening output to files before printing. Getting the output sharpening right is probably most important to achieving satisfactorily sharp prints.

Links:
www.pixelgenius.com
www.photoshopforphotographers.com

Kind regards,

Martin