First, can we all use DPI and PPI correctly? They're being tossed around in this thread incorrectly, and may be confusing to the OP. Image resolution is defined in PPI - pixels per inch. DPI, or dots per inch, is a function of the print machine itself, and has nothing
to do with the image. I think most people here are referencing DPI when they mean PPI. Here's a basic primer... http://www.andrewdaceyphotography.com/articles/dpi/
Now, with that mess out of the way, the method for enlarging/printing varies from printer to printer. For example, most modern LightJet printers can print images at 150 PPI with no quality loss whatsoever. I print most of my larger art prints at 150 PPI, which helps a lot with native print dimensions.
If I do need to enlarge it, I can usually get some significant upsizing from PerfectResize
before I start seeing any type of resampling artifacts. I know one world renowned fine art landscape photographer who shoots exclusively with a 5D Mark II and relies solely on PerfectResize to get his 10' wide prints and larger. I won't do any name dropping here, but he explained his editing process to me from camera to print (which I have totally adopted), and this is it in a nutshell:
- Import to Lightroom from camera body
- Basic exposure/correction edits within Lightroom
- Export image at 150 PPI with embedded printer profile (I use TIFF at this stage)
- Open in Adobe Photoshop to softproof and enlarge with PerfectResize (if enlarging is needed)
- Perform any final color edits/corrections as needed
- Apply final sharpening within Photoshop (sharpening is always a final step - apply NO sharpening in LR!)
- Save final version as max. quality JPG and send to printer
I have enlarged a photo I took 3 years ago with my 40D to 60" in the longest dimension with no quality reduction whatsoever. PerfectResize is the schitt.