Epson 4870 resolution setting vs true resolution vs print DPI (ATTN Epson 4870 Resolution Test contributors?)

Epson 4870 resolution setting vs true resolution vs print DPI (ATTN Epson 4870 Resolution Test contributors?)

Post by false_dmit » Sat, 10 Apr 2004 16:54:45


owe you a response. :)

Thanks once more for your outside opinion. It helped me revise my
appraisal of detail levels. I now agree with your opinion of the
600ppi image (more below). However, to my uninformed eye, there were
subtle hints of detail in the 4800 that the 600ppi image could not
fully reproduce--for example, some faint lines of the eyeglass frame.
I don't think the test image needs to go past 600ppi, but it's enough
of a borderline that I'll continue to watch for exceptionally sharp
prints that might benefit. Nice to know the extra resolution might
still come in handy for non-transparent media. :)

Kennedy McEwen < XXXX@XXXXX.COM > wrote in message news:< XXXX@XXXXX.COM >...

<snip>

(re. fractal resizing)

I also recall claims of exceptional compression, but that was ages
ago. I can't remember the ratio. It's probably changed since then,
anyway.

<snip>

(re. my test images)


The blur made the difference. Resizing directly to 4800 in PSE2 left
subtle but visible pixellation along curved edges. With your method,
it was indeed possible to nearly match the appearance of the 4800ppi
original starting from the 600ppi scan. I tried the USM at 100% and
was satisfied (not that I really know how to apply it properly... :)

And, of course, this is independent of dedicated scaling software or
future improvements in the PS/PSP algorithms. With all important
detail present at 600ppi, I'm comfortable setting aside the additional
resolution until it proves useful.

Any tips on independently acquiring knowledge such as when to resize
twice with a blur in the middle? I'd never have figured that out on
my own.


Out of curiosity, might some future algorithm do a better job at
resizing or sharpening the image when starting from a nice, clear set
of grains? It doesn't strike me as a forseeable concern, just the
only case in which the higher resolution would matter for my scans.

Regards,
false_dmitrii