Tuesday, November 29, 2011
The Right Resolution
The conventional wisdom says set 300 dpi and forget it, but it turns out that there’s more to optimizing image resolution for fine-art printing
|This Article Features Photo Zoom|
I suggest checking the Dimension option in the Guides panel to see a readout of the dimensions and resolution of the image at the final print size.
Printing From Lightroom
First off, let me disclose the fact that I'm partial to and perhaps a bit biased toward the Lightroom Print functionality. I had a little something to do with the development of printing from Lightroom. I've worked with the engineers to optimize the printing workflow and incorporate output sharpening for printing directly in Lightroom. As a founding member of a company called PixelGenius, LLC, I was involved with former PG member Bruce Fraser when he developed a sharpening plug-in called PhotoKit Sharpener. PixelGenius worked with Adobe to incorporate the PhotoKit output sharpening for inkjet and screen display directly into Lightroom and Camera Raw.
This is the readout of the native resolution of 236 ppi of the image when printed at the final print size.
Native Resolution Vs. Upsampled Resolution
Before I get into the details, let me outline exactly how I created the following print output tests. The original raw images were printed from Lightroom after setting the optimal capture sharpening in the Develop Module of Lightroom. As shown in the following figure, the image had the Amount, Radius and Detail sliders set for optimal sharpening. I also applied a bit of Luminance Noise Reduction because sharpening will often increase the perception of the noise (Fig. 1).
Here, the Print Resolution option has been checked in the Print Job panel, and the resolution has been set to 360 ppi.
I printed the image at both the native resolution and the upsampled resolution from Lightroom. I used the Standard setting on the Print Sharpening option and chose Glossy as the Media Type. In general, you'll want to select the glossy settings for papers considered photo papers and the matte settings for matte and watercolor papers. The sharpening requirements are different due to factors such as ink absorption, dot gain and the texture and reflectance of the paper. Lightroom automatically applies the proper output sharpening, based upon the resolution being sent to the print.
For the purposes of the test prints, I used two printers; an Epson Stylus Pro 4900 and a Canon imagePROGRAF iPF6300. Both printers represent the state-of-the-art, 12-color, high-end fine-art printers. The respective print dialogs were set up as shown in Figures 5 and 6. For the Epson printer, I used 8.5x11-inch Epson Ultra Premium Photo Paper Glossy. For the Canon printer, I used Canon's Photo Paper Pro II.
You'll notice that in both drivers' settings, I've chosen to turn off bidirectional printing. The odds are, printing normal output at these resolutions using bidirectional printing wouldn't negatively impact the final output. However, unidirectional printing eliminates any potential issues.
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