Digital BW, The Print

On 05/25/2011 11:45 PM, Mel wrote:
>
>
> Thanks Ernst, you have confirmed what the consensus seems to be that Epson printers like 720 ppi.
>
> Do you think it would make any difference to the print quality if I sent the image to the printer at 360 ppi as I haven't yet checked this out ?
>
> Mel

The 360 or 720 PPI input/native resolution of the printer does not 
describe the actual optical resolution of the print. It is just the data 
resolution it likes to work with for different quality settings. The 
real optical resolution could be any odd number in LPI or better MTF, if 
someone ever measured the last. Paper, ink, printer quality delivers 
that optical quality given optimal data to start from. Creating optimal 
data is a first step.

In time resampling routines improved in most drivers and so did the 
resampling algorithms in applications. The last can still be better than 
the drivers are but not always. Think about downsampling with and 
without anti-aliasing on for example grainy scans of B&W negatives, 
sometimes the smaller print has the same rough (aliased) grain the big 
one has. Some applications do the extrapolation in an intelligent, 
automatic step on the fly at print time, including print sharpening etc. 
Qimage and Lightroom for example. I hardly ever check what the remaining 
resolution is of a scaled print in Qimage as I know it will upsample the 
resolution to what the printer asks in a good way. In extreme cases I 
lower the print sharpening so upsampling artefacts are not getting 
exaggerated by sharpening. If the data is not sufficient for the size 
something has to be sacrificed, I rather have blurred detail at one foot 
viewing distance than sharp upsampling artefacts in a print several feet 
wide.

So not a straight answer, you have to test what differences in image 
quality you get with different approaches and the printer/media you use.

-- 
Met vriendelijke groeten,   Ernst

Try: http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/

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