Digital BW, The Print

Helen Bach wrote:
> I printed a checkerboard of one pixel squares and sets of lines one
> pixel wide at 1440, 720, 360, 300 and 288 ppi using the Epson driver
> and OPM on two different 2200s loaded with glossy paper.
> 
> With the Epson driver at the 1440 and 2880 dpi settings the only print
> that was free of artefacts was the one made at 288 ppi. The 360 ppi
> was close, and the definition of the lines was very good. At higher
> ppi the checkerboard and lines were not well defined.
> 
> With OPM the 360 ppi print had the fewest artefacts, but none were
> artefact-free. Moire-like lines were evident on all the prints, but
> least noticeable at 360 ppi. The definition was also best at 360 ppi.
> At higher ppi the checkerboard was not properly defined. 
> 
> There appears to be a difference between the 'native' horizontal and
> vertical resolution.
> 
> If the test patch had been too small, all the artefacts would not have
> been evident. The test patches were one inch square at 360 ppi.
> 
> Best,
> Helen 


This page describes some test methods that may be more 
suitable for photographic images:

http://www.ddisoftware.com/qimage/quality/


Ernst

                    --
           Ernst Dinkla


www.pigment-print.com
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