Because since LR 3, it's been shown that adding to the native resolution can aid in the rendering of some image detail...between 180-480 native res, you can get good results but adding 50% (or upsampling to 720 PPI) can produce superior results.
I to am a little confused by Jeff's two statements.
Jeff's 1st statement:
"First off, if the image resolution is 429 PPI at your print size, do not
downsample to a lower resolution. Depending on the image and detail, you
might find upsampling to 720 PPI may provide better super high frequency
image detail. High contrast diagonals or circles may render the edges better
when the resolution is set to 720. You should test to see on your own images
if you can tell a difference when going from 429-720. But you DON'T want to
waste the native resolution of the image by downsampling to 360 PPI. That
will produce less optimal results and simply leaving the native resolution
where it is and having LR apply the sharpening... " (...is this different
than what he says in his video)
Jeff's 2nd statement:
"Because since LR 3, it's been shown that adding to the native resolution
can aid in the rendering of some image detail...between 180-480 native res,
you can get good results but adding 50% (or upsampling to 720 PPI) can
produce superior results. " (So he is saying to add 50% upscaling when
your native resolution is between 180 - 480. If that result is above 360
ppi then use 720 PPI but if not then what? ...use 360ppi? And what if the
native resolution is greater than 480 PPI then just use 720 PPI? If that is
the case, then is he saying to print either at 360 or 720 PPI ?)
So my questions are:
- What happens when the native resolution - after being multiplied by
50% - is still lower than 360ppi (e.g. a cropped image being printed at 20
x 30" at Costco)? Are we to then upsampled by choosing 360ppi?
- And, only to apply this upsampling "50% rule" when the native
resolution is between 180 -- 480 PPI? - if not, upscale and used 720 PPI?
- If the above is true, again I ask, " Is he saying to print either at
360 or 720 PPI ?"
Jpegman