Digital BW, The Print

I am glad to see that you also cleaned up the LPI section of the file,
it was also hampered by jpeg artifacting, hence did not have clean
black to white line transitions and could be translated differently by
different drivers and was certainly not a valid test. If you want to
see a clean line from a printer, you have to start with a clean source
line. In fact, it's quite possible that any driver that excelled with
that portion of the test has some built in sharpening as the original
Pro24 RIP did.
This file has been floating around for quite a while used as a
technical reference, any source material used for comparisons like
this need to be very carefully considered.
Thanks for your efforts, anyone using the old should consider
replacing with these.
Tyler

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Daniel Staver"
<daniel@p...> wrote:
> > The compression probably messes up some of the transitions 
> > but I think the main thing you are seeing with the vertical 
> > lines is just the individual 256 steps of gray.  Photoshop 
> > will create two kinds of gradients -- 256 hard edged steps 
> > and smooth dithered gradients.  The "dither" option in the 
> > Gradient tool there a check box for the two kinds.
> 
> I think there are more problems than just the individual steps
> showing... Here I've increased the contrast on the stepwedge to make the
> problem more visible, then enlarged it quite a bit:
> http://daniel.staver.no/img/compressedstepwedge.jpg
>  
> > It's real easy to fix up the 21step.  Just select the top 
> > half and make a new gradient with dither on.  Select the 
> > bottom half, make a gradient with the dither off, and 
> > posterize to 21 levels.
> 
> I made a new cleaned-up version without artifacts and updated the
> technical.psd file with the new stepwedge. I also made a smaller version
> of for test prints. All three files are available here:
> 
> http://download.petraflux.com/technical.zip (3.59mb)
> 
> --
> Daniel Staver
> http://daniel.staver.no